EFFECT OF SHAPE OF AGGREGATE ON

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INDIAN HIGHWAYS A REVIEW OF ROAD AND ROAD TRANSPORT DEVELOPMENT Volume 41

Number 3

March 2013



Contents

ISSN 0376-7256

Page 2-5

Editorial

6-9

Meet the New President & Vice-Presidents of the Indian Roads Congress

10

Advertisement Tariff

11

New Developments



Technical Papers

12

Imperative of Risk Management in Highway Projects Indrasen Sing, Pralhad Kabra and Anand Kulkarni

27

Design of High Embankment Using Red Mud Sarat Kumar Das, Subrat Kumar Rout and Tapaswini Sahoo

35

Effect of Shape of Aggregate on Pavement Quality Concrete Kundan Meshram and H.S. Goliya

43

Nanotechnology in Highway Engineering Y.C. Tewari and R.S. Bharadwaj

49 Comparison Between Coarse Aggregate Shape Factors and Resulting mix Properties Using Conventional and New Universal Gauge Instruments Mohamed Ilyas Anjum 55-76 Circular’s Issued by Ministry 77

Tender Notice of NHs Kanpur

78

Tender Notice of NHs Lucknow

79

Tender Notice of NHs Madurai

80

Tender Notice of NHs Chennai

81

Obituary

The Indian Roads Congress E-mail: [email protected]/[email protected]

Founded : December 1934 IRC Website: www.irc.org.in

Jamnagar House, Shahjahan Road, New Delhi - 110 011 Tel : Secretary General: +91 (11) 2338 6486 Sectt. : (11) 2338 5395, 2338 7140, 2338 4543, 2338 6274 Fax : +91 (11) 2338 1649

Kama Koti Marg, Sector 6, R.K. Puram New Delhi - 110 022 Tel : Secretary General : +91 (11) 2618 5303 Sectt. : (11) 2618 5273, 2617 1548, 2671 6778, 2618 5315, 2618 5319, Fax : +91 (11) 2618 3669

No part of this publication may be reproduced by any means without prior written permission from the Secretary General. Edited and Published by Shri Vishnu Shankar Prasad on behalf of the Indian Roads Congress (IRC), New Delhi. The responsibility of the contents and the opinions expressed in Indian Highways is exclusively of the author/s concerned. IRC and the Editor disclaim responsibility and liability for any statement or opinion, originality of contents and of any copyright violations by the authors. The opinions expressed in the papers and contents published in the Indian Highways do not necessarily represent the views of the Editor or IRC.

From the Editor’s Desk

WAY FORWARD FOR INVESTING IN HUMAN RESOURCE IN ROAD SECTOR Dear Readers, The massive road development programme being witnessed since last few years and may continue for many more years also demands for adequate attention towards not only quantitative but qualitative availability of requisite man power to meet the demand of all spectrum of activities of this sector. Therefore, a focused attention is required to be given to this crucial issue . Today, the task in front of road engineers & professionals is not as simple as is commonly perceived. They have to function in a highly restrictive and competitive environment while catering to all issues related to financial, administrative and legal aspects in addition to the technical matters. The roads are considered to be one of the basic facility & amenity and thereby every citizen considers his right and demands for the same. Similarly, the other sectors of the economy take the availability of the roads as granted. This intricate paradoxical scenarios of “Cater-all” & “please-all” builds additional pressure on the road sector professionals. Therefore, the road sector, thereby per-se demands that the sectoral professionals should be exposed and equipped with the techno-management skills so as to allow him to make potential decisions & sustainable propositions within the limit of the resources, man, materials and machinery. Just remember, the quote from Holy Bhagwad Gita: “While doing your duties let me tell you, never bring in any of the attitudes of the outer self. Anger, hate, jealousy, attachment, all pertains to the outer self. Be in oneness with your inner self and do all of your duties; nothing will touch you or pollute you. This living identity with your inner self will give you the attitude of equanimity. The equanimous view of everthing that you come across whether it is man or material, is the ultimate goal of life.” Keeping the above in view, the road sector professionals can become the enablers of economic growth besides becoming in true sense the force behind empowering the people socially. However, the transformational potential results of human potential in the road sector are not very easy to comprehend. The human potential is a complex, composite of instinct, intelligence, personality, knowledge, skills, motivation, attitude and behaviours besides he is continuously shaped by his genetic inheritance, family, friends, education, surroundings as well as his personal life experiences. Therefore, to what extent the real human potential can be utilized gainfully by any sector depends upon the enabling environment prevailing therein. This is equally applicable for road sector also. Everyone knows that Indians constitute about 1/6th of the total world’s population. The unique Indian characteristics like commitment to inclusive growth, a long term perspective on business objectives and the much wanted proclivity for the “Jugaad – the improvisional ability to find workable solutions around seeming intractable problems” are internationally recognized and respected. However, these strengths are yet to be adequately be harnessed and channelized in the road sector.

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EDITORIAL Essentially, we will be able to analyze and deliver seamless economic benefits to the people of this great country, if different technologies are effectively harnessed in the road sector i.e. Leveraging technology for real growth through improvement in efficiency of deliverance and effectiveness of infrastructure created; Deployment of right people with right skills at the right place for optimization of human resource output, etc. It is always good to remember that when technologies, services and human intelligence convergence in radical creative ways, then a new powerful application emerge which transforms the industry and redefine the sector. As mentioned earlier, the road sector in India is witnessing unprecedented demand and pressure besides opening of the opportunities for this sector to be one of the most crucial enabler for sustainable economic growth. The employees, like in any other sector, in the road sector also require continuous up-gradation in their competencies and for this there is a need to have a proper system in place. The due investment in the road sector with an aim to bridge the competence gap towards building skill and productive work force to meet challenges of competition & sustainability in this sector requires a serious approach from all concerned. What we require today is an “out of box” skill enhancement approach not limited to just thinking but with demonstrative practices. Employees, as individuals, reflect the collective caliber of an organization. When an organization hopes to achieve its set out goals & objectives, the competence of the employees plays a major role. Therefore, “competency” provides the basis for investing in them when said in an organizational context. The scientific approach of competency modeling, measurement and deployment pave the way for continually enhancing collective capability. This is nothing but a concept of “partnering for progress” in a mutually beneficial way. Whenever any sector faces difficult time, then it is necessary to go for an in-depth introspection. The common result of sectoral introspections generally points towards the skill gap falling into three main areas :- Critical thinking, Communication capabilities and Ability to function as an efficient team. Even in the normal circumstances the organization/sector loses its pace of growth if the sector does not have “critical thinkers”. The critical thinking is an important requirement for effective problem solving system. It is generally defined as a type of higher order thinking that questions prevailing assumptions. Adept a logical reasoning, critical thinkers believe that there is more than one route to a desire outcome and they can leverage this flexible approach for optimal results. Organizations value critical thinkers for what they bring to the table, normally the ability to change the status-quo, driving change and innovation in the process. The critical thinking as a collective skill can be organizational building attribute but how many organizations as well as educational institute provide or consider for the same! The developed countries have their own system of skill development and harness the human potential for the benefits of their respective country’s goals, growth and development. The Japanese organizations have a system of “Genba” as their strength. It is a “bottom – up” approach and is the site where all important processes takes place, where people have full power and responsibility for what happens. This approach helps in involving & associating the workforce right from the grass root level and helps in building dedication and loyalty towards the organization. But in today’s scenario where the rapid technological changes are transforming the management approaches the world over, the road sector may become more strong and sustainable if a combination of “Bottom-up” and “Top-down” approach complementing each other is adopted. This Human Resource building approach may help in bringing required stability in the profession. INDIAN HIGHWAYS, March 2013

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EDITORIAL The road sector professionals is not only to manage but also to find solutions to the various issues right from the stages of conceptualization & planning stage in regard to land acquisition, rehabilitation, environmental clearance, environmental mitigation plans, financial tie-ups, material linkages, technological tie-ups, revenue collection (toll collection and management”), road safety management, etc. Therefore, comprehensive employee training programme with an emphasis on application and problem solving to serve as a drive to build the road sector organization on sustainable basis are needed to be given a serious consideration. In addition the new Techno-Management Technique of “Collaborative Leadership” is very much applicable for the road sector under the current scenario. It is a “Techno-Managerial” way wherein leaders avail the synergetic relationship between team members to create a bigger and better organizational structure. It is a articulated skill of working together, sharing knowledge, ideas and thoughts to achieve a common goal. It facilitates in creating an inhibition-free atmosphere beside resulting in significantly improved efficiency, productivity, accountability and competence. Moreover, using simulated scenario and other training modules, road sector employees can be exposed to the ‘quick thinking techniques’ to think quick & logically in order to come up with reasonable/ practical solutions within a given time. It is necessary that each road organization identify the training needs of their employees by carrying out specific ‘Training Needs Assessment’ (TNA) exercise on regular basis to identify the skill-deficit areas to bridge the same. The training modules should be such that they should create avenues to produce the breed of innovators and problem-solvers who are not afraid to push the boundaries at work. While working out the skill development training programme in the road sector, the outcome should also be evaluated on regular basis to ascertain whether the training imparted have imbibed the skills required to excel in the identified areas, analytical thinking and logical approach, zeal, persistence and confidence in the participants. The human resource development may not be accomplished without allowing and creating an enabling framework for research & development. R&D coupled with innovations requires an enabling environment to spread the benefits of development within the reachable reach of all stake-holders. However, research has much more to do with independent, unorthodox and creative thinking then with strategic thinking. This system practiced in some of the developed countries allows a large number of researchers to realize the fruits of their intellectual labour (which would have been harder to achieve in the country of their birth) and at the same time benefitting the country in which they carried out the research. Today, the need of the hour to make the Indian road sector vibrant and to allow holistic development of human resource of this sector demands for an urgent need to create enabling framework for research & development and enabling environment for innovators and their innovations so that applied research can be promoted and practiced. This may help in making this sunrise sector “Techno – Economically” sustainable. As mentioned earlier, we are witnessing the World’s biggest road sector initiatives. In order to ensure the resounding success and sustainability of results of this mega initiative, it is necessary that not only due investment is earmarked for Skill-enhancement , Skill- development, Skill- demonstration and Skillimparting programme but requisite enabling & supporting infrastructure is also required to be put in place. The data of the employees imparted skill-enhancement/ development trainings should be web-based, so that it may become accessible to all concerned for utilization of their attained expertise. It also needs to be evaluated whether all the employees working in the organization are deputed for the trainings on regular basis without any discrimination & prejudice. Till this is practiced in true spirit, the skill – enhancement & development in road sector or any sector may remain loop-sided. For example, the Contract Management is

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EDITORIAL an intricate ‘Technical–Art’. The road sector professional should be exposed to the same so that he may be able to differentiate between ‘Administering the Contract’ from ‘Management of Contract’ and ‘Managing the Management of Contract’. Proper skill development trainings may help in better project formulations and handling especially PPP projects, thereby reducing the scope of contractual disputes and additional claims. Generally the Capacity building & training activity is considered a low priority as well as an incidental activity rather than a focused activity. However, little thought is given to the fact that Trained & skilled employees can make difference to the pattern of growth, development, dynamism & prospects of an organization. The crucial aspect that employees significantly contribute to the reputation of an organization as well as to the country is generally given a miss. This aspect plays in vital role in making a organization globally competitive as well. If road sector organizations desire to spread their reach globally in an effective way then they may require making a sincere effort towards the capacity/skill building exercise. The government, PSU, educational institutes and private sector organizations should join their efforts and inter-link their competencies & capabilities in the field of capacity building with an aim to cover all the professionals & work force every 5 years period. PublicPrivate-Partnership concept in capacity building in road sector is very much essential in today scenario, which may be not only an economical proposition to all but will create a win-win situation in this activity. The sector should also consider instituting the awards for efficiency & innovations. The skill-building exercise should be separated from the routine working & functioning of the road sector organization to allow them a space to function in a holistic manner. They may also cater to inter-linkages with the educational & research institutions so that young talents may be tapped at the initial stages itself. This may help in creating internationally competitive road sector professionals. This grooming of young professionals to become mature contributors to the growth of road sector is very much needed. Towards the same it may not be out of the place to mention that for the first time , IRC has allowed the M.Tech and Research students to become regular members of IRC to tap their potential to contribute to growth/development in the road sector as well as to enhance their employability. In the recently held 73rd IRC Annual Session at Coimbatore, a novel initiative was taken by providing opportunity to PG Students/ Researchers to show-case their innovations/research work on IRC platform. The organizations normally get much higher return on the investment made by them in human resource development. Leaving aside the other benefits like large percentage of employee retention, increased productivity, image building, etc. the financial return to the organizations are manifold and the same is also applicable for the government sector as well , keeping in view that with higher productivity & efficiency the deliverance of the government projects & new initiatives also get improves, benefitting the public at large as well as nation as a whole. Therefore. Earmarked investment in the capacity building/skill enhancement/ skill development should be made an essential & regular feature covering all stake-holders and entire-work force. “The end product of education should be a free, creative mind, who can battle against historical circumstances and adversaries of nature”. (Quote of Dr. S. Radhakrishnan)

Place: New Delhi  Dated: 21st Feb 2013 INDIAN HIGHWAYS, March 2013

Vishnu Shankar Prasad Secretary General 5

MEET THE NEW PRESIDENT OF THE INDIAN ROADS CONGRESS

SHRI C. KANDASAMY Director General (Road Development) & Special Secretary to the Govt. of India

Shri C. Kandasamy joined Central Engineering Service (Roads) of Government of India in 1976 and have held various positions in the Ministry of Road Transport and Highways as well as in the National Highways Authority of India. He was on deputation with National Highways Authority of India as General Manager and was associated with Phase-I of NHDP (Golden Quadrilateral). As Chief General Manager Shri Kandasamy was involved in Phase –II of NHDP (North South & East West Corridors). He took most of the projects under his jurisdiction in North-South corridor through the BOT model. As Member (Technical), NHAI, he was incharge of Phase III (BOT) of NHDP projects. In his long and illustrious career spanning over 35 years, Shri Kandasamy has been involved in all aspects of development of National Highways including implementation of NHDP. Shri C. Kandasamy held various positions in the Ministry and elevated to the post of Director General (Road Development) and Special Secretary in December 2011. Shri C. Kandasamy is a Life Member of the Indian Roads Congress. He is an eminent engineer of repute and is closely associated with Indian Roads Congress. He is Convenor of Apex Committees, Highways Specifications & Standards, Bridges Specifications & Standards and General Specifications & Standards of IRC. Besides, he is also instrumental in preparation of IRC Codes, Specifications, Manuals etc. Shri C. Kandasamy has been elected as President of the Indian Roads Congress during its 73rd Annual Session held at Coimbatore (Tamil Nadu) in January 2013.

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INDIAN HIGHWAYS, March 2013

MEET THE Immediate Past PRESIDENT OF THE INDIAN ROADS CONGRESS

SHRI P.N. JAIN Born on 22nd July 1957, Shri P.N. Jain graduated in Civil Engineering from L.D. College of Engineering, Ahmedabad in the year 1979 with distinction. He qualified the Direct Recruit Examination conducted by the Gujarat Public Service Commission and joined the Roads & Buildings Department, Govt. of Gujarat as Executive Engineer in 1980. Shri Jain was promoted as Superintending Engineer and Chief Engineer in the years 1990 and 1997 respectively. He has been involved in execution of various works, such as, Construction and Maintenance works of State Highways, Major District Roads, Other District Roads including Major and Minor Bridges of Gandhinagar, Mehsana, Banaskantha and Kutch Districts including Capital City Gandhinagar. He also worked as Secretary, Gujarat Slum Clearance Board, Ahmedabad especially in various schemes related to slum dwellers of low, medium and high income group of housing projects in different cities/ towns of Gujarat State. As Chief Engineer (Quality Control) and Addl. Secretary, he inspected many on-going projects related to Roads, Bridges & Buildings. Shri Jain worked as Technical Advisor to Vigilance Commissioner in the capacity of Chief Engineer & Addl. Secretary for more than 4 years. He also worked as Chief Engineer (Capital Projects) and Additional Secretary in charge of various works of Construction & Maintenance of Roads, Bridges & Buildings etc. of Ahmedabad & Gandhinagar. Shri Jain has also worked as Arbitrator for disputed cases of Government & Contractors.

INDIAN HIGHWAYS, March 2013

As Chief Engineer & Director, Staff Traning College, Roads & Buildings Department, Gandhinagar, he was responsible for providing Departmental and Special Training to Inservice Engineers of Roads & Buildings Department, Irrigation Department of Government of Gujarat of various cadres in collaboration with Experts of National and International Highways Institutes, Project Management Institutes, such as, UTiMMalaysia, NITHE-New Delhi, CRRI-New Delhi, NICMAR-Pune, GIDB-Gandhinagar, IEI (GSC) – Ahmedabad, Nirma University, GICEA-Ahmedabad and LD Engineeing College-Ahmedabad. Shri Jain is presently working as Chief Engineer (NH) & Additional Secretary, R&B Department, Gandhinagar looking after the construction and maintenance of National Highways of Gujarat and other important projects, such as, Railway Over Bridges, Railway Under Bridges on Annuity-BOT & CRF works. Shri P.N. Jain is Life Member of various other Professional Bodies like, Indian Buildings Congress, Institution of Engineers (India), Indian Concrete Institute, Institution of Indian Public Administration, Gujarat Institute of Civil Engineers & Architecture and Computer Society of India-Gujarat Chapter. Shri P.N. Jain was elected as President of the Indian Roads Congress during its 72nd Annual Session held at Lucknow (U.P.) in November, 2011 and he is Immediate Past President and member of Executive Committee for the year 2013.

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MEET THE NEW VICE-PRESIDENTS OF THE INDIAN ROADS CONGRESS

SHRI SANDEEP B. VASAVA Shri Sandeep B. Vasava did B.E. (Civil) with distinction from M.S. University, Baroda in 1989. In 1990 Shri Vasava passed the Gujarat Public Service Commission Examination topping the list. In 1991, he joined the Road & Building Department, Government of Gujarat as Assistant Executive Engineer. He was promoted as Executive Engineer in the year 1995 and posted in the National Highways Division, Baroda. In 1999, Shri Vasava was promoted as Superintending Engineer, National Highway Circle, Baroda. In this capacity, he has handled major BOT Project of bridges across river Mahi and Narmada on National Highway No. 8. In 2002, he was promoted as Chief Engineer and posted as Managing Director, Gujarat State Road Development Corporation. In 2006, Shri S.B. Vasava was elevated to the post of Chief Engineer & Additional Secretary (National Highways). At present, he is working as Chief Engineer (P) and Additional Secretary and Chief Executive Officer of GSRRDA. Shri Vasava is involved in Construction and Maintenance of Rural Roads and Implementation of PMGSY scheme of Government of India. He has also served on various Committees of Government of Gujarat. He was also the Member Secretary for the Sub Group of State Roads for Formulation of 11th and 12th Five Year Plan for Planning Commission, Government of India. He is also Council Member of the Institution of Engineers. Shri Sandeep B. Vasava has been elected as Vice-President of the Indian Roads Congress during its 73rd Annual Session held at Coimbatore (Tamil Nadu) in January 2013.

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SHRI KIRAN KUMAR YALLAPPA MAHINDRAKAR, VSM Shri Kiran Kumar Yallappa Mahindrakar graduated in Civil Engineering from BVB College of Engineering & Technology, Hubli in 1976. After graduation, he was involved as Site Engineer/Resident Engineer in construction of one mile long Malaprabha Right Bank Canal Aqueduct over Bennihalla River and completed 72 Nos of well foundations in black cotton soil and erected substructures from 1976 to 1979. Shri Mahindrakar joined as Assistant Executive Engineer as first batch of Border Roads Engineering Services in BRDB/MoRTH in 1979 through Combined Engineering Services Examination of UPSC. He was involved in road construction in far flung areas of North East devoid of basic amenities and having poor road communication. He showed his technical competence in planning & construction of bridges on NH-44. Due to his excellent result oriented attitude he was selected for Masters in Highways (Transport Engineering) from University of Roorkee and passed out with Gold Medal in 1986. Shri Mahindrakar was promoted as Executive Engineer in 1992 and in this capacity he was responsible for construction, maintenance of roads, bridges and causeways, widening of roads in insurgency infested region in the States of Nagaland and then in Manipur. He was promoted as Superintending Engineer in 1997.As Superintending Engineer he was responsible for construction of roads of strategic importance along the border in the States of Arunachal Pradesh and J&K. Shri Mahindrakar was promoted as Chief Engineer in 2003. In this capacity, he was responsible of road construction including widening of strategically important roads and National Highways in the States of Mizoram and Arunachal Pradesh. For his exemplary services, he was awarded Chief of Army Staff Commendation Card in 1986 and for his meritorious services he was awarded by His Excellency the President of India with VISHISHT SEVA MEDAL during Republic Day 2006. Presently, he is working as Dy. Director General (Pers) looking after Human Resources Department called Pers Dte in HQ DGBR, New Delhi. Shri Kiran Kumar Yallappa Mahindrakar has been elected as Vice-President of the Indian Roads Congress during its 73rd Annual Session held at Coimbatore (Tamil Nadu) in January 2013.

INDIAN HIGHWAYS, March 2013

MEET THE NEW VICE-PRESIDENTS OF THE INDIAN ROADS CONGRESS

SHRI A. SAMUEL EBENEZER JEBARAJAN Shri A. Samuel Ebenezer Jebarajan completed his B.E. (Civil Engg) from Govt. College of Engineering, Salem, Tamil Nadu in 1978. Shri Jebarajan started his Engineering carrier in Bharat Heavy Electricals Ltd., Trichy and was involved in execution of Multi-storied Buildings during 1978-79. He joined as Assistant Engineer in Corporation of Chennai and designed various storm water drains for Chennai during 1979-80. Then in 1980, he joined the Highways & Rural Works Department of Tamil Nadu and executed Bridge works, Rural Roads and National Highway Projects in Trichy and Salem Circle areas. He has put in exemplary service in Rural Development Wing and executed infrastructure projects, Road & Bridge works and various housing projects. He has executed Bridges in Chennai, across Coovam River and Major Bridge works across Kaveri River near Madurai. He held various positions in the divisions of Quality Control, execution of Major Ring Roads, Bridge works including maintenance of roads. He has put in four years of service under the aegis of Highways Research Station, Chennai in Concrete lab and as Deputy Director (Soils) and implemented new technologies, such as, usage of copper slag for GSB and pavement designs for distressed highways and other traffic studies for RITES and other researches in Traffic & Soils. He completed his M.Sc (I.T) from the Alagappa University by distance education. As Superintending Engineer (H) Shri Jebarajan has monitored execution of major Bridge and Road works in South Tamil Nadu. When he was promoted as Chief Engineer (H) he took charge as the Chief Engineer (H), Planning, Design & Investigation, Chennai during 2011-12 and monitored design of major bridges and grade separators. Shri Jebarajan is presently working as Chief Engineer (H), Metro monitoring the execution of major Grade Separators, Link Roads and other prestigious projects in Chennai Metropolitan area under State Fund and World Bank Projects. His earnest participations in various training programs under NITHE, New Delhi, international organizations such as IRF at New Delhi and IABSE at Chennai and at Venice, Italy has strengthened his technical ability besides the knowledge of Primavera for planning. Shri A. Samuel Ebenezer Jebarajan has been elected as VicePresident of the Indian Roads Congress during its 73rd Annual Session held at Coimbatore (Tamil Nadu) in January 2013.

INDIAN HIGHWAYS, March 2013

SHRI SWATANTRA KUMAR Shri Swatantra Kumar graduated in Civil Engineering from Malviya National Institute of Technology, Jaipur, Rajasthan in 1996. He has also done Post Graduation (MBA–Marketing) from All India Management Association, New Delhi in the year 2000. Shri Swatantra Kumar has started his career with Renaissance Aqua Sports Pvt. Ltd. New Delhi in the year 1996 as a Site Engineer and was involved in design and construction of Swimming pools and health club of different capacities. In the year 1997, he joined Aimil Ltd. as Engineer, Business Development for North India. Aimil is a market leader addressing instrumentation needs of the nation for the last 8 decades. Aggressively involved in providing total instrumentation solution to the wide range of industries like Roads, Buildings, Education, Thermal power, Hydro Power, Cement etc. He was also actively involved in getting accreditation of NABL and ISO for his Company. Shri Swatantra Kumar was promoted as Business Manager in 2005 and in this capacity he was responsible for business development of imported products of leading manufacturers from U.S.A. and Europe in frontier areas of Instrumentation. During this period, he was also responsible for promoting NDT (Non- Destructive Testing instrument ) to different sectors like DMRC, IITs, NITs, CPWD, PWD , Irrigation Department etc. Shri Swatantra Kumar currently working as Asstt. General Manager at M/s. Aimil Ltd. New Delhi, heads the Delhi Regional Team and he is instrumental in promoting state-of-art instrumentation across the country and also involved in bringing about various system improvements within the company. He is also responsible for providing technical support to Aimil users in India and neighboring countries like Nepal, Bhutan, Srilanka, Bangladesh etc. He has been serving IRC in the capacity of Council Member for the last 5 years. He has been an active member of Instrumentation Committee (G-5) of the Indian Roads Congress. Shri Swatantra Kumar has been elected as Vice-President of the Indian Roads Congress during its 73rd Annual Session held at Coimbatore (Tamil Nadu) in January 2013.

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INDIAN HIGHWAYS, March 2013

NEW DEVELOPMENTS Highways Research Station, Chennai has been accredited with the ISO-9001-2008 Certification. The Salient Features and facilities available with them as informed by HRS are as under:



   

SOILS LABORATORY Key Features ¾ Pavement Design ¾ Road Rehabilitation studies ¾ Ground Improvement Techniques ¾ Pavement Materials Testing ¾ Sub Soil Exploration ¾ Pile Load Tests ¾ Design mixes ¾ Structural Evaluation Facilities x Digital CBR x Digital Consolidation Apparatus x Digital LVDT for pile load testing x Geogauge x Electrical Density Gauge

BITUMEN LABORATORY Key Features ¾ Tests on Bitumen & Aggregate ¾ Mix Design for Pavements ¾ Evaluation of value added products – Modified Bitumen, Modified Bitumen Emulsion ¾ Failure Studies ¾ Bituminous Mix Characterisation Facilities x Rotational Viscometer x Dynamic Shear Rheometer x Universal Testing Machine – HYD25II x Beam Fatigue Apparatus x Gyratory Compactor x Laboratory Model Circular Test Track.

CONCRETE LABORATORY Key Features ¾ Testing of Concrete Materials ¾ Mix Design ¾ Testing of Steel ¾ Destructive & Non Destructive Testing ¾ Condition Assessment of Bridges. Facilities x Universal Testing Machine x Compression Testing Machine x PUNDIT/Ultrasonic test x Rebound Hammer x Half Cell Potentiometer x Load Testing facility for Bridges x Heavy Duty Test Floor

TRAFFIC LABORATORY Key Features ¾ Functional Evaluation ¾ Axle Load Survey ¾ Travel Time Study ¾ Junction Improvement Study ¾ Surface Conditioning Assessment ¾ Various studies to reduce Accidents ¾ Traffic Improvement Techniques Facilities x Portable Axle Weigh Pad x Hand held Roughometer x Speed Meter x ROMDAS x Advanced Data Collection Equipment

Exclusive Training Facility available for Highway Engineers Well Equipped Library with Rare Publications, Technical Journals Research Activities on Highway Engineering using latest Techniques, Sophisticated Equipments Eight Regional Laboratories with Sophisticated Equipments

For more details please Contact Shri E.L. Satyamoorthi, Chief Engineer (H), QA&R, Highways Research Station, Chennai – 25, Ph No: 044- 22354851, Fax No: 044- 22354852, Email: [email protected]; [email protected]

The Institution of Engineers (India), Roorkee Local Centre will be organizing a Workshop on “Ground Improvement Techniques for Difficult Ground Conditions” on 16th April 2013 at IIT Roorkee. Noted speakers from IIT Roorkee and Ground Improvement Industry are going to deliver expert lectures. For registration please contact Dr. Satyendra Mittal, (Convenor, Workshop), Associate Professor, Department of Civil Engineering, IIT Roorkee, Uttarakhand, Tele. + 91 11 01332-285837, Mobile + 91 9760014237, 9412074237; E-mail: [email protected].

INDIAN HIGHWAYS, March 2013

11

TECHNICAL PAPERS

Imperative of Risk Management in Highway Projects Dr. Indrasen Singh* Pralhad Kabra** and Anand Kulkarni**

Abstract Project risk is the cumulative effect of the chances of uncertain occurrences adversely affecting project objectives. Project risk management is the art and science of identifying, assessing and responding to project risk throughout the life of a project and in the best interests of its objectives. The constant goal of project risk management should be to move uncertainty away from risk and towards opportunity. The goals of risk management, therefore, are to identify project risks and to develop strategies, which either reduce them or attempt to avoid them. An infrastructure development is more prone to risks than ordinary industrial projects. Risks consequently, have the ability to adversely affect the implementation of a highway project. A successful highway project development and project finance transaction is therefore, the suitable identification, allocation and management of risks. The successful implementation of a project, it is essential that person involved in its Implementation whether engineers, lawyers, legislators, executives bankers or civil servants be sensitive to the risk-involved in the project and formulate most suitable structure for the management of such risks. If the persons involved in the implementation of a project are able to identify the risks regarding a proposed project and the means of its adequate allocation and reddressal or better more sensitive to the necessity of their adequate mitigation, it would go a long way in enabling the implementation of highway projects.

1

Introduction

Risks are nothing more than the variables or circumstances associated with the implementation of a specific project that has the potential to adversely affect the development of a project, Risks include circumstances or situation, the existence or occurrence of which, will in all reasonable foresight, result in an adverse impact on any aspect of the implementation of the project.

In projects management terms the most serious effects of risk can be summarised as follows: a)

Failure to keep within the cost estimate

b)

Failure to achieve the required completion date

c)

Failure to achieve the required quality and operation requirements

In highway construction projects risks are related to various aspects such as the contractor’s ability, design, technology, political and socio-economic environment etc. Moreover the impact of the risk varies from project to project depending upon the size of the project (its physical size, financial value, resources involved), the level of the novelty involved in the projects, the level of involvement of the number of agencies and the complexity of the projects. Risk management is the process of recognising risk, assessing it and managing it. The first and the most important step in attempting to deal with exposure to risk is to identify them which is called Risk identification. Many decision makers believe that the principal benefits of risk management come from the identification rather than the analysis stage The tools and techniques for risk identification include documentation reviews, information gathering methods, checklists, assumption and SWOT ( Strength, Weakness, Opportunities and Threat) analysis, and any appropriate diagramming techniques.

*

Professor, School of Civil Engineering, Lovely Professional University, Phagwara, Punjab, E-mail: [email protected]

**

Former PGP: ACM Students, NICMAR Goa.

12

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS Structural reviews and methods of team participation, through brainstorming etc, and the use of checklists, flowcharts, cause and effect diagrams, etc. to help identify risks are the core of this transformation step.

3.1

The outputs include the identification of all risks, what are likely to be the conditions under which they will occur, and if the risk identification process has identified further investigation of risk related matters in other knowledge areas ( scope, time, cost, etc).

a)

Where it is true that most projects contain a number of reasonably standard and recognisable risk situations, each new project requires careful and individual consideration.

c)

It establishes the conditions that make the project workable with environment

d)

It must also identify and assess the other hidden factors that are elements, situations or circumstances that influence the project but that can be unknown in the beginning or imply a risk to the project.

e)

Project review is a continuous process defining the critical parameters, which need to be controlled and monitored throughout the project life cycle analysis.

3.2

Determination of Scope of the Project

2

Project review is carried for all construction projects before implementation. With respect to the case study of project review involves:

a)

Experience with similar projects

b)

Depth of knowledge and

c)

Unique project environment

The study of risk of the project in terms of the total cost of the project has been divided under four cost centers that are:

Estimation of risks as well as their absolute parameters

b) It calls for technical and financial scrutiny of proposal and assessing the degree of each risk at each project phase.

RISK IDENTIFICATION PHASE

In the construction of any project, risk identification is done on the basis of:

Project Review

Collection of data regarding various risks influencing the project is now assessed in terms of degree of impact thus defining the scope of the project. Experience on past projects is a major source of risk impact.

a)

Technical

b)

Financial

Three major sources of experience can be summarized as follows:

c)

Socio-political

a)

Corporate

d)

Statutory



3

RISK IDENTIFICATION PROCESS

The process of risk identification for any construction project involves two steps:

This is a knowledge gained in the previous projects, which is dispersed throughout the organisation. The information may be stored as personnel memories, diverse reports or as database that compares plans and outcomes.

b)

Project Team

a)

Project Review



b)

Determination of Scope

This is sample of the corporate experience possessed by the individuals within the particular project team. Often such knowledge

INDIAN HIGHWAYS, March 2013

13

TECHNICAL PAPERS is very relevant although it might be limited and possibly biased.



*

What warranties will be provided relating to the construction?

c)

External



*



May be other projects from outside world from which relevant lessons could be learnt.

What completion and testing procedures will be used?



*

What is the timetable for construction?



*

Are their restrictions on subcontracting with third parties for financing or construction?



*

Who will be responsible for site surveys, ground and geotechnical investigations. Utility surveys, land issues and environmental surveys?



*

Who will be the project manager?



*

What are the development risk?



*

Who will finance construction cost overruns, and what assurances will lenders have that the funds will be available when required?



*

Are their joint and several completion liabilities amongst the construction contractors, equipment suppliers and subcontractors?



*

Who will monitor the construction, approve the contractor invoices, and provide commissioning and completion certificates?



*

Will planning approvals be required? Who is responsible for obtaining planning approvals and permits?



*

Will the construction contract include contractor incentives?



*

What percentage of the total project value will be required to secure with a performance bond?



*

What are the obligations and responsibilities relating to capital expenditure for major water and sewerage facilities?

4

RISKS IN PROJECTS

Risks in projects are many and varied. The identification, assessment and valuation of risks are difficult and indispensable tasks in the analysis of bids and contracts. Depending upon their nature, risks can be categorised as technology risk, design and latent defect risk, completion risk, cost overrun risk, traffic revenue risk, operation risk, demand risk, debt servicing risk, legal risk, political risk, partnering risk, regulatory risk, financial risk, environmental risk and physical risk. These risks can be dealt by a number of ways. They may be priced in the bid, insured, or assumed by the contractor, the owner or both. 4.1

Check List for Projects

Long term contractual relationships inevitably involve risk. Careful design of contracts and regulatory arrangements can help both reduce the level of risks and ensure that any remaining risks fall on the party that is capable enough to manage them. These issues are taken up in more detail and all the key risks are incorporated in the form of checklist. i)

Who is responsible for construction risk?



*





14

*

*

Who is responsible for delays in construction and higher than expected construction costs? What is the scope of the construction work and of the specifications for project infrastructure? Is there an annex for this information? What is the mechanism for changing the specifications?

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS ii)

What are the political risks?



*

How stable is the country?



*

Will export credit agencies guarantees against political risk?



*

Is insurance available?

iii)

What are the revenue risks?



*

How secure is the cash flow?



*

Willingness by users to pay for facility?



*

If the government provides support for the project. What form will that support take?



*

Minimum revenue undertakings.

guarantees

determined? What are the payment terms? Is there a grace period for payment? Under what conditions may the regulator waive or allow a delay in payment?

give

or



*

Will the developer maintain segregated debt service accounts for principal and interest payments?



*

What type of sponsor guarantee will the arrangement require a construction completion guarantee, performance guarantee, debt service guarantee for senior bonds or loans, shareholder loan guarantee?

iv)

What are the regulatory risks?



*

Is there an independent regulator?



*

Standby equity or subordinated debt to meet revenue shortfalls.



*

What limits are placed on the regulator’s discretion?



*

Tax privileges



*



*

Duty exemptions for imports of capital equipment.

What are the procedures for appealing regulatory decisions?



*

Assurances on the liability of foreign exchange and the exchange rate with foreign currencies relevant to the project, free transfer of funds or interest rate guarantees.

What compensation or cost pass through arrangements are there to safeguard the developer from shifts in regulatory ground rules?

4.2

Risk Analysis & the Simulation Approach



*



*

Capital grants and loans. Lines of credit, or letters of credit.



*

What are the legal and administrative mechanisms required, for the government to provide this additional support?



*

Will the government provide a guarantee for a minimum amount of new works per year, including any additional government revenue sources required to complete these works?



*

Who will be responsible for paying penalties for noncompliance with environmental regulations in the event of deterioration? How are penalties to be

INDIAN HIGHWAYS, March 2013

Risk analysis is essentially method of dealing with the problem of uncertainty. Uncertainty usually affects most of the variables that one combines to obtain analysis of cost estimates, an economic rate of return or net present value, analysis of financial return, or any of the other indicators that may be used to evaluate feasibility report. Sometimes one deal with this uncertainty by combining values for all input variables, chosen in such a way that they yield a conservative estimate for the result of the analysis. In other cases one may select the best estimate value, that is, the value that one thinks most likely to be achieved. Both these solutions imply a decision: firstly, to look at the project with a conservative eye, secondly, to disregard the consequences of any variations around the best estimate value. Both can lead to biased decisions. 15

TECHNICAL PAPERS For example, if one combines only conservative estimates of variables, final result is likely to be “over conservative”. On the other hand by using only best estimate values one fails to take into account the other values of the variables that might result in substantial variations in the estimates. Thus biasing ones decision on a single value of the decision variable one may by taking more risk than one intend to. The purpose of risk analysis is to eliminate the need for restricting one’s judgement to a single optimistic, pessimistic or “best” evaluation by carrying throughout the analysis a complete judgement on the possible range of each variable and on the likelihood of each value within this range. At each step of the analysis these judgements are combined at the same time as the variables themselves are combined. As a result the product of the analysis is not just a single value of the decision variable but a judgement on the possible range the decision variable around this value, and a judgement on the likelihood of each value in range. These judgements take the form of probability distribution. That is to say each possible value of each variable is associated with a number between 0 and 1, such that for each variable the sum of all these numbers or probabilities is equal to 1. These probabilities, which are called subjective probabilities because they present some degree of subjective judgement, follow all rules or traditional probability theory. From a mathematical point of view risk analysis therefore consists of aggregating probabilities. The idea underlying the Monte Carlo technique is simple. When we say that a project has a 30 percent chance of earning a 10 percent return, we mean that if we had a large number of similar projects we would accept about 30 percent of them to earn a 10 percent return. Conversely, if we had a great number of projects and if 30 percent of them earn a 10 percent return, we could say that the probability of a 10 percent return is 30 percent. Hence the simplest application of the Monte Carlo technique is to build a great number of projects with the characteristics of one we are interested in and see how many of them earn a 10 percent, 15 percent,

16

20 percent, etc. In practice, the value of each of the uncertain variables is chosen by random selection, and the rate of return or some other decision variable is computed for the project defined by these values. The process is repeated many times and the results are statistically analyzed. The only difficulty is in making sure that the distribution of the values of each of the input variables as it emerges from the random selection is consistent with the distribution for that variable chosen for the analysis. 5

EVALUATION OF RISK

Cooke and Slack (1984) investigated the process of evaluation of risks. According to them, the risk inherent in any of the decision option can be a result of the decision maker’s inability to predict or estimate the outcomes or the internal effects of the decision options within the organisation or the environmental conditions, prevailing after the decision. The range of possible outcomes conveniently describes whatever the source of risk is. There are many methods of evaluation of risk from the most simple probability concepts to the most complex utility functions and expert system. Probably the earliest industrial use of risk methods was with PERT/RISK, which originally referred to the variation of estimates of the activity duration, and assuming their independence, was used to calculate the probable variations of duration. For instance, Corporate at use the various probability of interdependence as exemplified by network analysis can be overcome by simulation. 5.1

Probability Concepts

The likelihood of something happening is usually quantified either as a probability figure or as asset of odds. The various methods based on this concept are: a)

The Classical Method

b)

The Relative Frequency Method

c)

The Subjective Method INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS d)

The Bayesian Decision Method

5.1.1 The Classical Method It is the oldest and the simplest approach. In this theory, the probability is based on equal chances of events happening. 5.1.2 The Relative Frequency Method If the event is something which is easily repeatable or occurs frequently of it’s own across. The likelihood of the event occurring may be deducted by examining its previous history. This method of deriving probabilities is called the relative frequency method. Both of the above methods can only be used to forecast events that are repeatable or repealing. But many management decisions involve assessing the chance of something happening which has not happened before and possible will not happen again i.e. risk event. 5.1.3 The Subjective Method This method of probability is based on subjective judgements of experts in the field no matter how soundly it is based on their experiences. Especially for risk analysis, most of the information will be qualified in the form of subjective data only and such methods become essential to quantify the risks. 5.2

The Bayesian Theory

This theory was evolved by the British mathematician Thomas Bayes (1763) involving the estimation of unknown probabilities and making decisions on the basis of new (sample) information. The Bayesian approach employs both personal judgement and empirical evidence and it has been used in the modeling of the probable activity duration overruns in the Fuzzy set model.

as to make explicit the options open to the decision maker, the state of the nature pertinent to the decision and the decision rule used to choose between the options. In fact a number of decision rules have been commonly put forward as being helpful in understanding the nature of the decision. The four decision rules are: a)

The Optimistic Decision Rule

b) The Pessimistic Decision Rule c)

The Regret Decision Rule

d)

The Expected Value Decision Rule

5.3.1 The Optimistic Decision Rule This approach to select the preferred option is to consider all possible circumstances and choose option that yields the best possible outcome. If dealing with costs, this rule sometimes called as the minimum cost rule and if dealing with revenues it is called as the maximum revenue rule. 5.3.2 The Pessimistic Decision Rule A decision maker who took the very optimistic view to the once described above would follow the reverse procedure in this case. Each option would be examined and the worst possible outcome for that option identified. That option would be selected which provides the best of the worst outcomes. 5.3.3 The Regret Decision Rule This is based on a deceptively simple but extremely useful question i.e. “If one decides on one particular option then with lined sight how much would he regret not having chosen what turns out to be the best option for a particular set of circumstances?” Disadvantages of Regret Decision Rule

5.3

Decision Matrix

A decision matrix is a method of modeling straight forward decisions under uncertainty in such a way INDIAN HIGHWAYS, March 2013

If the alternative chosen is the one that gives the least cause for regret when compared with another alternative, then the degree of regret will depend on 17

TECHNICAL PAPERS ii)

For each variable, estimate the probability distribution, which most clearly reflects the decision maker’s degree of belief as to the likelihood of the variable taking any value.

All the above three-decision rule do not consider the potentially most useful factors within any management decisions. This is the expert’s estimate of the likelihood of a particular decision occurring. The principle of expectation “weights” each outcome by the likelihood of its occurring. The expected values are merely an indication of the worth of each option.

iii)

Choose the endogenous variable, the measure of outcome, which will be used to evaluate the options, for example, the probable mean distribution.

iv)

Determine the functions, which relate the uncontrollable exogenous variables to the endogenous variables.

5.4

v)

Randomly the function, which relates the uncontrollable exogenous variables to the endogenous variables.

vi)

Repeat step (v) many times until a distribution of the values for the endogenous variables is formed.

the other options considered. This can cause logical inconsistency. 5.3.4 The Expected Value Decision Rule

Decision Trees

One limitation of the decision model is the simplistic ways in which it treats the option open to the manager. Many management decision in reality are a series of reality sequential decisions, where choices made at one point in time can change the probability of their decision happening or alter their consequences. The decision tree format enable sequential decisions to be represented and the consequences of future decision to be treated back of assess their influences on the present decisions. In fact, a decision matrix can be represented as a decision tree. 5.5

Risk Simulation

Risk simulation is a technique that allows a more sophisticated approach to modeling the uncontrollable factors that influence the outcome of the decision. By making continuous probability estimates for each controllable factor the technique produces decision outcomes that are also continuous probability functions. This gives a much clearer picture of the spread of outcomes possible than the decision tree model that produces single-figure expected values. This technique that was originally described by Hertz can be briefly summarized as follows: i)

18

Choose the uncontrollable exogenous variables (risk factors), which are considered to have a significant bearing on the decision.

Simulation technique especially the Monte Carlo is widely used in risk analysis and evaluation. But it has the disadvantage that, it requires mainframe computers such as OPSS etc. It is expensive to use. Simulation methods to date have suffered from excessive detail. Their lack of concern for external effects and their general limitation of one dimension being extrapolated to others, e.g. time to cost. 5.6

The Utility Theory

An attempt was made by David Bernoulli in 1738 to quantify individual’s emotions about money or individuals’ value system. However, it was not until 1944 that a formal mathematical theory was set forth by Yon Neuman and Morgenstern to describe, in a quantitative sense, a decision maker’s attitude and feelings about money. Their theory becomes the modem utility theory. The concept of utility is psychologically oriented and refers to subjective satisfaction derived by an INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS individual from the possession of a given number of units of a particular commodity. The utility theory referred to herein is often thought of as a concept for measuring the attitudes of an individuals (decision maker) towards risk and uncertainty. The theory first enunciates certain axioms obeyed by a rational man and the show that these lead to the existence of a preference ordering or utility function ‘IT which satisfies the following properties: 1.

‘U’ is defined as the set of all possible outcomes

2.

Outcome ‘X’ is preferred to outcomes ‘Y’ if and if U (X) > U (V)

3.

A decision giving chances T of achieving outcomes ‘X’ (I < 1 < n) is preferred to one giving chances q of achieving outcomes Y (I < j < n)

Where probability = q = I if and only if

PU(X) > q U (Y)

Property (2) shows that a utility function ranks the outcome in the preference order while property (3) shows that one set of probabilistic outcomes i.e. preferred to another if and only if it has a higher expected utility. It follows from this property that a rational man ill always act so as to maximise his expected utility. 5.7

Expert System

A lot of research is being done on artificial intelligence and expert systems. Specifically one of the most sophisticated models that can be developed for risk management is making use of knowledge-based systems or human-computer cooperative systems.

a knowledge-base. It is designed to warn project managers of risks that may follow etc. While doing this, the logical thinking and the intuitive thinking of the managers is accounted for in the system. 5.8

The analytical hierarchical process was originally developed by Saaty (1980). It provides a flexible and easily understandable process to analyze project risks. It provides a promising alternative in complex situations involving a multi-criteria decision making methodology. It has structured approach to decisionmaking that eliminates much of the guesswork and confusion or ordinary methods of synthesizing an overall explanation for a system. It organises the basic rationality by breaking down the problem into it’s smaller constituent parts and then guide the decision maker through a series of pair-wise comparison judgements (which are documented and can be re-examines) to express the relative strength or intensity of impact of the elements in the hierarchy. These judgements are then translated into numbers. The AHP includes procedures and principles used to derive priorities among criteria and subsequently for alternative solution. 6

INDIAN HIGHWAYS, March 2013

RISK ANALYSES

The model used for the analysis of the risks that have been identified with the case under study is the analytical Hierarchical Process. The model and its process have been described in this paper. Implementation of integrated Road development programme in the city of Kolhapur on BOT basis has been taken as a case study of risk analysis. 6.1

This system is designed to assist the project managers in achieving more effective control over risks by providing them with appropriate knowledge, gathered from many project managers and compiled into

Analytical Hierarchical Process (AHP)

Analytical (AHP)

Hierarchical

Process

Model

The analytical hierarchical process was originally developed by Saaty (1980) is a multi-criteria decision 19

TECHNICAL PAPERS making methodology. It allows the decision maker to set priorities and make choices on the basis of their objectives, knowledge and experience consistent with their intuitive thought process. It fulfils the requirements for an executive decision system where decision makers can structure a system and its environment into mutually interacting parts and then synthesize them by measuring and ranking the impact of these parts of the entire system. A conventional approach to risk analysis suffers two major limitations: a)

It requires detailed qualitative information that is not normally available at the project planning stage.

b)

The problems are ill defined due to subjective nature, which leads to imprecise decision during their applicability.

The deductive as well as systems approach of AHP within an integrated, logical framework removes these limitations and makes the understanding of complex situations simpler. The structured approach to decision making eliminates much of the guesswork.

Once the problem has been structured, expert judgments are solicited from the decision maker relating to each fact of the problem. The methodology foes not require any numerical guess. The degree of importance of the elements at a particular level with respect to those in the immediate upper level is judged by the decision maker and measured by a procedure of pair wise comparisons repeated for all elements at each level. The ultimate goal of doing this is assign numerical values to the subjective judgements on the relative importance of each element with values varying from one to nine. The pair wise comparison scale used for the risk analysis of the project under study is given in Table 1. This is also the fundamental scale of AHP and consists of numbers (one to nine) associated with intensities of importance or preference. This methodology has been shown to provide remarkably accurate results. The consistency of judgement in any decision making process is vital because of its impact on the quality of decision. Unfortunately, lack of inconsistency is expected to exist in almost any set of the pair wise comparison. The consistency of pair wise judgements is measured in AHP from the Consistency Ratio (CR):

AHP has been applied successfully to a wide variety of problems over then past several years that include Architecture (Satty and Erdcnncr, 1979), Conflict Resolution (Gholam Nezhad 1983 and 1984) Predictions (Saatyy and Gholam – Nezhad 1982 Ciholam - Nczhad 1985)

CR = CI/RI

Where,

CI = Consistency Index



RI = Random Index

Consistency Index, CI = ( λ max – n) (n – I) The AHP uses a hierarchical approach where the problem is decomposed into a number of interrelated factors and then arranged in a hierarchical order. The number of levels in the hierarchy depends on the complexity of the problem as well as the degree of detail needed to solve the problem. Each factor is evaluated with respected to the other related factors.

20

Where,

λ max = large eigen value



n = ran of the matrix

The Random Index is given in Table 2.

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS Table 1 Pair wise Comparison Scale

Intensity of Definition Importance 1 Equal Importance 2 Moderate importance of one over another 5 Essential or strong importance 7

Very strong importance

9

Extreme importance

2,4,6,8

Intermediate Value

Explanation Two elements contribute equally to the Property Experience and Judgment slightly favour one element over another Experience and judgement slightly favour one element over another An element is strongly favoured and its dominance is demonstrated practice The evidence favouring one element over another is of the highest possible order of affirmation When compromise is needed

Table 2 Random Index Table

N

Random Index

1

0.00

2

0.00

3

0.58

4

0.90

5

1.12

6

1.24

7

1.32

8

1.41

9

1.45

10

1.49

6.1.1 Steps of Analytical Hierarchical Process The following are the steps to be taken in formulating the risk-analysis model Analytical Hierarchical Process: Step 1: The scope of the total project is classified through the Work Breakdown Structure (WBS). The whole project is classified into manageable work packages in accordance with the similarities of activities. Risk analysis is considered separately for

INDIAN HIGHWAYS, March 2013

the various packages. In the project under study as risks pertaining to cost overruns are being studied; the entire project cost is divided into four cost centers. Step 2: In this step, identification of risk factors and sub-factors is done for specific work packages and the establishment of a hierarchical risk structure from the package concerned. Various techniques, ranging form simple interviews and the application of the analyst’s own experience to the Delphi technique, can be used for the identification of risk factors and sub-factors. Thus, the risk factors relating to each cost center are determined and an AHP model is developed. This model has been shown subsequently. Step 3: The relative weights of the various risk factors are determined by pair v comparison according to the severity of risk on the basis of questionnaire filled experienced project managers and planning engineers. The scale of giving weightages has already been shown in Table 1. This creates a detailed analysis of the ranking the risk factors for the cost centers under consideration with respect to the severity of risk. Step 4: the level of likelihood of each factor is determined with respect to high medium and low 21

TECHNICAL PAPERS risk. The risks having probability more than six are considered to be high risks, those with probability from one to six are considered to be medium risks and those with less than one are considered as low risks. Step 5: The likelihood of the levels of risk are synthesized and determined in this step. The likelihood’s of high, medium and low total are determined by aggregating the relative weights through the hierarchy. Step 6: A sensitivity analysis is carried out. The outcome of the analysis above is dependent on the hierarchy established by the management, and the relative judgements made about the elements of the problems. Changes in the hierarchy may lead to

change in the outcome. The effect of the change can be examined through the sensitivity analysis. Step 7: The overall risk of the cost centers is determined. The likelihood levels of risk and the weights of different levels of risk are combined to determine the overall risk of all cost centers. Step 8: The cost centers are ranked in accordance with the risk probability and severity. The result from the determination of the overall risks of cost centers are used to ranks the cost centers with respect to their risks. The results of the Analytical Hierarchical Process for the risks affecting the cost overruns of the project under study are given in Table 3.

Table 3 Risk Identified in Various Stages by Using AHP Sl. Stages of Project No

1

Preconstruction

Risk Identified in various stages

Likeli- Seve- Chance Weigh- Risk Percent hood rity of tages Number Risk (L) (S) detec(W) = L*S* Share tion (D) D*W

Reliability of TOR

1

10

3

0.68

20.40

2

Risk of getting the clearance approved

1

10

3

0.68

20.40

3

Reliability of the DPR

1

8

1

0.68

5.44

Type of client

3

5

3

0.68

30.60

5

Change in requirement

5

5

5

0.68

85.00

6

Delay in decision & approach

5

5

5

0.68

85.00

7

Change in Government policy

3

5

3

0.68

30.60

8

Interpretation of the requirements

3

8

3

0.68

48.96

46.24 4

Client team

280.16 Experience of the team

3

10

3

1.58

142.20

10

9

Design team

Faulty design

1

10

3

1.58

47.40

11

Continuity of the team

1

2

3

1.58

9.48

12

Level of design information

3

5

5

1.58

118.50

13

Practicality of the design

1

10

1

1.58

15.80 333.38

14 Construction

Scope of the Project

3

10

1

2.26

2.90

3.45

67.80

15

Deviation in site parameters

3

10

3

2.26

203.40

16

Location

3

10

3

2.26

203.40

22

0.48

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS Sl. Stages of Project No

Risk Identified in various stages

Likeli- Seve- Chance Weigh- Risk Percent hood rity of tages Number Risk (L) (S) detec(W) = L*S* Share tion (D) D*W

17

Access Problem

5

5

1

2.26

56.50

18

Legal restrictions

5

10

1

2.26

113.00

19

Contaminated

1

5

1

2.26

11.30

20

Occupies

5

5

1

2.26

56.50

21

Noise abatement

5

5

1

2.26

56.50

22

Time overruns

5

5

5

2.26

282.50

23

Fixed price

8

2

3

2.26

108.48

24

Performance & financial

3

5

3

2.26

101.70

25

Dispute

8

8

5

2.26

723.20

26

Ability to carry out construction

3

10

3

2.26

203.40

27

Testing

5

8

3

2.26

271.20 2628.3

28 Geological

Presence of faults

8

10

29

Weak foundation

5

8

1

1.58

379.20

1.58

63.20

30

Water table

5

8

5

1.58

316.00

31

Earthquake

5

10

5

1.58

395.00 1153.4

32 Environment

Loss of flora

8

10

3

1.58

379.20

33

Loss of fertile

8

10

3

1.58

379.20

34

Rehabilitation

10

10

5

1.58

690.00

35

Radiation damage

0

-

-

1.58

00.00

36

Damage due to

0

-

-

1.58

11.93

00.00 1584.4

37 Fuel

Non availability

3

10

5

1.13

169.50

38

Floods

5

10

5

1.1.

282.50 452.00

39 Contractual

Form of contract

1

5

1

0.68

3.40

40

Type of tender

3

5

1

0.68

10.20

41

Claims

8

8

3

0.68

130.56

42

Arbitration

5

8

5

0.68

136.00 280.16

43 Financial

Delay in

5

5

5

1.13

141.25

44

Delay in

5

5

5

1.13

141.25

45

Restrictions on cash Flows

3

2

3

1.13

20.34

46

Inflation rate

5

5

5

1.13

141.25

47

Exchange rate risk

5

5

5

1.13

141.25

INDIAN HIGHWAYS, March 2013

27.19

16.02

4.68

2.90

23

TECHNICAL PAPERS Sl. Stages of Project No

Risk Identified in various stages

Likeli- Seve- Chance Weigh- Risk Percent hood rity of tages Number Risk (L) (S) detec(W) = L*S* Share tion (D) D*W

48

Inability of the contractor to pay

8

10

3

1.13

271.20

49

Tax Implications

1

5

8

1.13

45.20

50

Repatriation of profits

1

5

8

1.13

45.20 946.94

51

Political & regulatory Risk

3

8

5

0.68

81.60

52

Conflict between government bodies

5

8

5

0.68

136.00

53

Inadequacy of legal frame work

1

8

3

0.68

16.32

54

Risk of change in legal & regulatory environment

1

10

5

0.68

34.00

55

Price setting policy

3

5

3

0.68

30.60

56

Enforceability of contracts

3

8

3

0.68

48.96 347.48

57 Operation Risk

Number & contractors

58

performance

of

sub

3

5

3

2.27

102.15

Defective works

3

10

3

2.27

204.30

59

Hidden problems

3

10

5

2.27

340.50

60

Force majeure

1

10

10

2.27

227.00

61

Materials & Plant availability

1

10

3

2.27

68.10

62

Risk of maintaining the load factor

3

8

3

2.27

163.44

63

Bankruptcy of sub contractor

3

5

1

2.27

34.05

64

Variations in change orders

3

5

5

2.27

170.25

65

Risk of failure of structure

3

10

5

2.27

340.50

Total

9.80

3.59

1650.29

17.06

9666.83

100

6.1.2 Risks Identified by the Analytical Hierarchical Process Model

Total estimated cost is divided into four components as given below:

Where, T1 = Design or Specification Risk T2 = Material Risk



24

T3 = Equipment Risk T4 = Cash Flow Risk F2 = Price Escalation Risk INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS

F3 = Inflation Risk



F4 = Payment to Contractor Risk



P1 = Legal Risk



P2 = Accidents Risk



P3 = Non Performance by the Contractor Risk



S1 = Clearance Risk



S2 = Change in Local Laws Risk



S3 = Disapproval of Pans Risk

Table 4 Ranking of Risk Causing Cost Overruns, as Obtained from the Analytical Hierarchical Process

Cost centers Financial Statutory Technical Socio-Political 7

6.1.3 Advantages of Analytical Hierarchical Process The observed advantages of AHP are as following: i)

It divides the complete project into controllable work packages through the work breakdown structure.

ii)

It classifies the various sources of risk associated with the work packages

Rank 1 2 3 4

CONCLUSION

In today’s rapidly growing Highway projects, the quantum of risk has also increased considerably. Highway projects involve various types of risks such as Construction risk, Operation & Maintenance risk, Political risk, Revenue risk and Regulatory risk. Various stages of project like Gestation stage, Development stage, Construction and Start up stage and Operational stage involves different types of risks. For analyzing these risks there are various methods available which are as follows:

iii) It identifies risk factors and sub-factors and their hierarchical order.



Evaluation of Risk



Probability Concepts

iv)

It determines the contributions of specific risk to time and cost overruns and too Nonconformance to quality standards



Decision Trees



Decision Matrix



Risk Simulation

It enables the management to control high-risk work packages by the use of a highly competent team.



The Utility Theory



Expert system



Analytical Hierarchical Process (AHP)

v)

vi)

It helps in formulating contract strategy.

vii) It creates a achievement.

confidence

about

project

viii) It extends valuable support for the project’s participating agencies in the decision making process.

In project management terms the most serious effect of risk can be summarized: a)

Failure to keep within the cost estimate

b)

Failure to achieve the required completion date

c)

Failure to achieve the required quality and operational requirements.

6.1.4 Result of AHP on Project under Study Table 4 shows of cost centers on the basis of impact due to the risks leading to cost overruns.

INDIAN HIGHWAYS, March 2013

As far as rating agencies role is concerned. A scientifically graded project would lend itself to a more accurate and reliable estimate of risks associated with the infrastructure project. 25

TECHNICAL PAPERS 8

RECOMMENDATIONS



Before signing the contract agreement, all the parties should study all the areas where there is possibility of involvement of risk. The contractor should be well versed with the site conditions before signing the contract. Proper finance should be arranged before the start of the project. The uses of new technologies and construction methods would reduce the time of construction. This will reduce the project completion risk. By forming joint ventures with strong parties, the risk involved will be distributed evenly.

● ● ●



3.

Prasanna Chandra (2002), ‘Financial Managers, Tata McGraw-Hill Publishing Company Ltd., New Delhi, Sensitivity analysis, RA.

4.

CODE (October 2003), ‘Risk Management in Construction Projects’, Publication Bureau, NICMAR Pune.

5.

Construction World, Vol. 7 No. 11, August 2005.

6.

Prasanna Chandra (2002) Projects, Tata McGraw-Hill Publishing Company Ltd., New Delhi.

7.

Prasanna Chandra (2001), ‘Financial Management’, Tata McGraw-Hill Publishing Company Ltd., New Delhi.

8.

Chris Chapman and Stephen Ward (1997), Project Risk Management’, John Willey & sons, New York.

9.

Singh, Indrasen, “Risk Management in Contracts” Seminar on Urban Infrastructure Renewal – Challenges, Impediments & Solutions, CIDC, India Habitat Centre, New Delhi, January 31, 2008.

10.

Singh, Indrasen, “Risk Management on Public Private Participation in Highway Project”, a National Seminar on Public Private Partnership in Highway Sector, Indian Roads Congress, New Delhi, August 28-29, 2009.

REFERENCES 1.

Ramakrishnan R (January 2004), Construction Journal of India, 8-11

2.

Laxton (1996) ‘Guide to Risk Analysis & Management’, Oxford Butterworth-Heinemann, Jorden Hill.

26

INDIAN HIGHWAYS, March 2013

DESIGN OF HIGH EMBANKMENT USING RED MUD Sarat Kumar Das*, Subrat Kumar Rout** and Tapaswini Sahoo***

Abstract National Highways, port connectivity, expressways and remote area connectivity through Pradhan Mantri Gram Sadak Yojana (PMGSY) are major part of infrastructure development. This has resulted in construction of high embankments, underpass and flyovers using vast amount of natural resources. This paper discusses use of red mud as an embankment material based on laboratory investigation and finite element analysis. The geotechnical properties such as specific gravity, plasticity index, compaction characteristics, consolidation and triaxial shear strength of red mud are presented. Stability analysis of embankments using above geotechnical properties are discussed.

1

Introduction

Construction of embankments has become an integral part of major road works in construction of National highways, expressways and other connectivity. Presence of expansive soils, shortage of borrow area soil creates lots of hindrance to such projects. From environmental consideration, vast use of top soil in available area is also matter of concern as its takes thousands of years to form the natural top soil. Now there is a great concern regarding use of alternate/ waste material in place of natural top soil. Aluminum industries are producing huge quantity of industrial waste known as red mud. Globally there are approximately 70 million tones of red mud being produced every year with less than half of this is used. Storage of this unutilized red mud takes vast tracts of usable land. Highly alkaline red mud (pH ranges from 10.5 to 13) is typically deposited as slurries with 15 to 40% of solids. The red mud ponds are situated above the normal ground level. This also

pollutes the environment in terms of water and land contamination. So in order to avoid these difficulties there is a need to characterize the red mud to be used as an alternate embankment and sub grade material. This paper presents part of the study related to geotechnical characterization of red mud as embankment material. Examples are presented for the embankment design using Finite Element Method (FEM) based on above geotechnical parameters. This study will help the engineers, planners to use red mud as an alternate material particularly for difficult soil in borrows area or at least to avoid the environmental degradation. 2

LITERATURE REVIEW

Parekh and Goldberger (1976) and Li (1998) defined red mud as highly alkaline (PH=11-13) waste material, whose mineral components can include hematite, goethite, gibbsite, calcite, sodanite and complex silicates with cation exchange capacities are comparable with kaolin or illite minerals. The red mud has more than 50% as clay size particles. Very limited efforts have been made in various parts of world regarding utilization of red mud as an embankment material. Some of the initial efforts in geotechnical characterization of red mud are presented as follows. Vogt (1974), observed that the in-situ undrained shear strengths are typically vary high compared to uncemented clayey soils and it has very high friction angles (φ) varying from = 38º-42º.

*

Associate Professor, Department of Civil Engineering, National Institute of Technology, Rourkela E-mail: [email protected]

**

Asst. Professor, Department of Civil Engineering, ITER, SOA University, Bhubaneswar

*** Research Scholar, Department of Civil Engineering, National Institute of Technology, Rourkela

INDIAN HIGHWAYS, March 2013

27

TECHNICAL PAPERS Somogyi and Gray (1977), Fahey and Newson (1998) observed that red mud has compression index Cc = 0.27-0.39 similar to silty-clay soils, coefficient of permeability k = 2-20 x10-7 cm/s and coefficient of consolidation Cv = 3 – 50 x10-3 cm2/s. Red mud tends to have low plasticity [e.g., WL = 45%, IP = 10%] and relatively high specific gravity (GS = 2.8-3.3). There is lack of clay mineralogy and these wastes show many geotechnical properties similar to clayey tailings found in other mineral processing (Vick 1981). It was observed that limited study has been done to find out geotechnical properties of red mud and also little geotechnical information available about Indian red mud. For the high embankment stability analysis is most important factor which is generally found by slope stability analysis. The limit equilibrium method with circular slip surface or wedge/planer slip surface is assumed for this analysis. But in limit equilibrium method, it is not possible to find out the stress and strain inside the soil mass. It is also important to study the case of hydraulic fracturing particularly with water table in one side of embankment. Hence, in this study an attempt has been made to characterize red mud as an alternate embankment material. Accordingly necessary geotechnical laboratory investigations were made. Finite Element Method (FEM) is used to study the stability of embankment based on above geotechnical properties. The flow through the embankment is also studied along with the stress variations inside the embankment mass to study the case of hydraulic fracturing. 3

EXPERIMENTAL PROGRAMME

3.1

Materials and Test Programme

The red mud used in the experimental work was collected from National Aluminum Company Ltd. NALCO, Damanjodi Koraput, Odisha and a typical discharge point is shown in Fig. 1.

28

Fig. 1 Discharge of Red Mud as Slurry into the Pond

The geotechnical properties of red mud like specific gravity, plasticity index, swelling index, linear shrinkage, grain size classification, compaction characteristics, and triaxial shear tests were investigated as per relevant IS codes. The basic physical properties of red mud are shown in Table 1. It can be seen that the red mud is highly alkaline with pH value of 11.4 and the specific gravity (3.34) is also very high compared to soil due to the presence of hematite. It has low plasticity and low volumetric and linear shrinkage. As per IS soil classification it can be classified as silty soils of low plasticity as well as clayey soils of low plasticity. (ML-CL). Fig. 2 shows the X-ray diffraction pattern of red mud and it was observed hematite as major minerals with other minerals like goethite, gibbsite, rutile, boehmite, sodanite and absence of common clay minerals. The high specific gravity of red mud is due to presence of hematite. 4

RESULTS AND DISCUSSION

The results of other laboratory tests are presented in the following section. INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS 4.1

Grain size Classification

The grain size distribution curve of red mud is presented in Fig. 3. It can be observed that more than 90% of particle sizes of red mud are fine grained (< 0.075mm). The grain size distribution of a local soil and fly ash are also presented in Fig. 3 for comparison. The fly ash used in the present study was collected from hopper of the thermal power plant of Jindal Power Limited, Raigarh, Chhattisgarh. It was observed that grain size distribution of red mud and fly ash is comparable and these are finer than local soil. The plasticity of red mud is found to low (PI = 7.2) due to absence of clay minerals as shown in Fig. 2. This low plasticity may help to use red mud as a subgrade material.

Fig. 2 X-ray Diffraction Pattern of Red Mud.

Table 1 Geotechnical Properties of Red Mud

Sl. No

Properties

Red mud

1

pH value

11.4

2

Specific Gravity

3.34

3

Plasticity characteristics Liquid limit (%)

24.8

Plastic limit (%)

17.5

Plasticity index (%)

7.2

4

Volumetric shrinkage (%)

1.6

5

Linear shrinkage (%)

5.3

6

IS classification

4.2

Fig. 3 Grain Size Distribution Curves of Red Mud with other Soils

ML,CL

Compaction

The compaction curve for red mud using light compaction and heavy compaction is shown in Fig. 4. Fig. 4 also describes the compaction characterisation of fly ash and a local sandy soil for comparison. It can be seen that red mud has higher Maximum Dry Density (MDD) in comparison to other materials. This high MDD value may be attributed to high specific gravity of red mud. INDIAN HIGHWAYS, March 2013

Fig. 4 Compaction Characterisation of Red Mud with Fly Ash and Other Soil

29

TECHNICAL PAPERS 4.3

Triaxial Shear Strength

The stress- strain curve for the red mud compacted (Light compaction) at OMC and MDD is shown in Fig. 5 at different confining stress (σ3). The tests were conducted under consolidated undrained condition. The cohesion (c) of red mud is found to 28.8kN/m2 and the angle of internal friction (φ) as 34.830. The shear strength value of the red mud is found to more as compared to fly ash (c = 18kN/m2 and φ = 28.40). It was also observed that red mud has higher φ value compared to ordinary soil. 4.4

CBR

The unsoaked and soaked CBR value of red mud is found to 6.4 and 1.2, respectively. Based on CBR value it can be observed that red mud can be effectively used as a sub grade material in dry state. 5

FINITE ELEMENT ANALYSIS

In the present study the finite element analysis of the embankment is done using FEM based softwarePLAXIS (Brinkgreve et al. 2008).

program for geotechnical applications in which different soil models are used to simulate the soil behavior. It’s implementation consists of three stages, known as input stage, calculation stage and post processing (curves) stage. Input stage contains model design, assigning the material parameters, boundary conditions, loading and meshing. In the present analysis 15-node triangular element is considered for meshing which contains 12 stress points. In PLAXIS, stresses and strains are calculated at individual Gaussian integration points rather than at nodes. In the calculation stage, analysis type is chosen such as Plastic, dynamic, consolidation and phi-c reduction. The assigned loads are activated in this stage and analyzed. In the post processing stage, curves are plotted between various calculated parameters such as load Vs displacement. To compare with the limit equilibrium method in addition to stress-strain calculation, the Factor of Safety (FOS) of slope is calculated using Phi-c (φ-C) reduction method. 5.1.1 Φ-C Reduction Method Phi-c reduction is an option available in PLAXIS to compute FOS for the stability problems. This option can be selected as a separate calculation type in the general tab sheet. In the Phi-c reduction approach the strength parameters tanφ and c of the soil are successively reduced in the same decrement. The total multiplier ∑Msf (MSF) is used to define the value of the soil strength parameters at a given stage in the analysis:

Fig. 5 Stress-Strain Curve of Red Mud under Consolidated Undrained Triaxial Shear Test

5.1

Finite Element Analysis Using PLAXIS

PLAXIS (Brinkgreve et al. 2008) is a finite element 30

ΣMsf =

tan Φ input tan Φ reduced

=

cinput creduced



... (1)

Where the strength parameters with the subscript ‘input’ refer to the properties entered in the material sets and parameters with the subscript ‘reduced’ refer to the reduced values used in the analysis. ∑Msf is set to 1.0 at the start of calculation to set all material strengths to their unreduced values. The variation of

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS MSF with displacement is presented to find out the FOS.

2.56 which is comparable to that obtained using limit equilibrium method.

It was also observed that red mud is a dispersive (erodible) material. Hence following IRC:SP:58-2001 an attempt has been made to provide soil cover with local soil similar to that of fly ash embankment. The properties of local soil and red mud for the present analysis are presented in Table 2. Table 2 Soil Properties for Mohr-Coulomb Model Mohr-Coulomb parameters 3

Unit weight(kN/m )

Local soil 16

Red mud 19.8

-3

5.832 x 10-4

Permeability(m/day)

5 x 10

Cohesion(kN/m2)

30

28.8

Internal friction(degree)

15

34

Young’s modulus(kN/m2)

3500

1771

Poisson ratio

0.3

0.34

5.2

Fig. 6 The PLAXIS Model for the Slope Using only Red Mud.

Stability Analysis of Embankment Slope

For the embankment slope analysis the top width of a typical 2-lane road is taken as 14m (7m carriage way + 1.5x2 paved shoulder + 2x2 earth shoulder). Similarly for 4-lane road it is taken as 26m. The embankment slope considered are with slope 1:2 (1 vertical: 2 horizontal). The embankment height considered for 10m and 15m. The stability analysis of embankment with red mud only and red mud with soil cover is analysed.

Fig. 7 The Shear Failure Surface of Slope as Per PLAXIS Model for the Slope Using only Red Mud.

5.2.1 Example 1 In the 1st attempt, it was tried to analyze the embankment using only red mud as the base material. The slope height is kept 15m and the slope inclination of 1:2. Model diagram with its deformation mesh is shown in Fig. 6. Fig. 7 shows the shear failure results of PLAXIS analysis. This failure surface refers to failure surface as per limit equilibrium method and the result has been verified earlier (Subramaniam, 2011). The variation of the MSF with displacement is shown in Fig. 8 and the FOS of the slope is found to INDIAN HIGHWAYS, March 2013

Fig. 8 The Factor of Safety of Slope as per PLAXIS Model for the Slope Using only Red Mud.

31

TECHNICAL PAPERS 5.2.2 Example 2 In this example an attempt has been made to analyze embankment by covering the red mud with the local c-φ soil. The slope geometry as described in Example 1 is analyzed with cover material of horizontal 3.0m on sides 1.0m on top as shown in Fig. 9. Fig. 10 shows the shear failure results of PLAXIS analysis. The variation of the MSF with displacement is shown in Fig. 11 and the FOS of the slope is found to 2.58.

Fig. 11 The Factor of Safety of Slope as per PLAXIS Model for the Slope Using Red Mud and 1.0m Vertical Soil Cover.

Drainage

Fig. 9 The PLAXIS Model with its Deformation Mesh for the Slope Using Red Mud and 1.0m Vertical Soil Cover.

Fig. 10 The Shear Failure Surface of Slope as per PLAXIS Model for the Slope Using Red Mud and 1.0m Vertical Soil Cover.

32

Another important aspect of high embankment is the effect of ponding of water on one side or both sides during monsoon. This flood water may lead to hydraulic fracturing (Sherard 1986) and may ultimately lead to failure. Hydraulic fracturing by réservoir water acting on the upstream face of the dam core causes concentrated leaks of water to enter the core. If the core material is dispersive then it may lead to cause piping. Hydraulic fracturing due to high water pressures might have caused leakage or failure of many embankment/dams (Sherard, 1986). In the present case as the core material red mud is dispersive (Sahoo, 2012) in nature, it is necessary to study the hydraulic fracture. The Hydraulic fracturing occurs particularly if the phreatic line is above the tension zone of the emabnkment. Identification of tension zone and phreatic line also help in provision of filtre bed. Such a study also made here to find the effect of ponding. Hence, an attempt has been taken at same soil cover with consideration of phreatic line. The PLAXIS model with its deformation mesh and its position of phreatic line, shear failure surface and effective stress diagram in Z-Z direction is shown in Figs. 12, 13 and 14 respectively. From the effective stress diagram it was observed that little tensile stress occurred at the surface of the embankment which is

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS much above the phreatic line. Hence, there is less chance of hydraulic fracture. Similar study was also made for different height and width of embankment with only red mud and with red mud core and soil cover. The comprehensive results have been presented in Table 3. It was observed that in all cases the FOS is more than 2.5. As per IRC:75 and IRC:SP:58, FOS should be more than 1.5, hence, high embankment can be constructed using red mud with soil cover. Though, there is a need to study other aspects like economy and convenience in construction.

Fig. 14 Effective Stress Diagrams for the Slope Using Red Mud and Soil Cover of 1.0m Vertically in ZZ Direction

Table 3 Factor of safety of embankment of different width and height with only red mud and red mud with soil cover (Width, height) mt, red mud, cover

Fig. 12 The PLAXIS Model with its Deformation Mesh for the Slope Using Red Mud and 1.0m Vertical Soil Cover with its Phreatic Line.

FOS

14, 10 (RM)

2.966

14, 10 (RM, soil)

3.00

14, 15 (RM)

2.558

14, 15 (RM, soil)

2.576

26, 10 (RM)

2.967

26,10 (RM, soil)

2.99

26, 15 (RM)

2.533

26, 15 (RM, soil)

2.541

Conclusion This paper described the analysis of high embankment using red mud based on the laboratory geotechnical investigation and the stability analysis using FEM. Based on the observations and discussions thereof following conclusions can be made: 1.

Fig. 13 The Shear Failure Surface of Slope as per PLAXIS Model for the Slope Using Red Mud and 1.0m Vertical Soil Cover with its Phreatic Line.

INDIAN HIGHWAYS, March 2013

Red mud is highly alkaline with PH value of 11.9 and the specific gravity is also very high compared to soil. It has low plasticity and low volumetric and linear shrinkage with 90% of particle finer than 0.075mm.

33

TECHNICAL PAPERS 2.

Red mud has higher Maximum Dry Density (MDD) in comparison to other materials due to high specific gravity.

3.

The angle of internal friction value of the red mud is found to more as compare to fine grained soil and fly ash.

4.

The FOS of the embankment with only red mud and red mud with local soil cover found to be more than required as per IRC specification.

5.

Using seepage analysis through embankment to check against hydraulic fracturing, it was observed that there is less chance of hydraulic fracture.

6.

This limited study shows that red mud has the potential to be used as an embankment material. More study is being conducted regarding economy and convenience in construction and safety during construction.

7

REFERENCES

1.

Brinkgreve. R.B.J, Broere.W, Waterman.D (2008). “PLAXIS -2D (Version 9.0)”, Delft University of Technology and PLAXIS b.v., The Netherlands.

2.

Fahey, M., Newson, T. A., and Fujiyasu, Y. (2002). “Engineering with Tailing.” Invited Lecture, Proc., 4th Int. Conf. On Environmental Geotechnics. Rio de janeiro, Brazil, 2, 947-973, Balkema, Lisse.

3.

IRC:SP:58-2001. “Guidelines for Use of Flyash in Road Embankments”, The Indian Roads Congress, Jamnagar House, Shahjahan Road, New Delhi-110011.

4.

IRC:SP:75-1979. “Guidelines for the Design of High Embankments”, The Indian Roads Congress, Jamnagar House, Shahjahan Road, New Delhi-110011.

5.

Parekh, B., and Goldberger, W. (1976). “An Assessment of Technology for Possible Utilization of Bayer Process Muds.”US EPA, EPA-600/2-76301.

6.

Sherard, J.L (1986) “Hydraulic Fracturing in Embankment Dams,” Journal of Geotechnical Engineering, Vol. 112, No. 10, pp 905-927.

7.

Somogyi, F., and Gray, D. (1977) “Engineering Properties Affecting Disposal of Red Mud.” Proc., Conf. on Geotechnical Practice for Disposal of Solid Waste Materials, ACSE, 1-22.

34

8.

Subramaniam, P. (2011). “Reliability Based Analysis of Slope, Foundation and Retaining wall Using Finite Element Method.” M.Tech Thesis Submitted to National Institute of Technology Rourkela.

9.

Sahoo, T. (2012). “Experimental and Numerical Analysis of Foundation on Red Mud.” M.Tech (R) Thesis Submitted to National Institute of Technology Rourkela.

10.

Vick, S. G. (1981). Planning, Design and Analysis of Tailing Dams, Wiley, New York, 369.

11.

Vogt, M. F. (1974). “Development Studies on Dewatering of Red Mud.” 103rd Annual Meeting of AIME, Dallas, Tex., 73-91.

INDIAN HIGHWAYS, March 2013

Effect of Shape of Aggregate on Pavement Quality Concrete Kundan Meshram* & H.S. Goliya**

Abstract Flaky and elongated particles have larger specific surface area which results in higher demand of cement paste in cement concrete mix. These particles impede compaction or break during rolling and decrease the strength of pavement layer. The effect of different percentages 0 to 50% of Combined Flaky and Elongation Aggregates (CFEA) for Pavement Quality Concrete (PQC) on the compressive and flexural strength of cement concrete and on the properties of aggregate, such as, bulk density, impact value, crushing value, water absorption have been studied in this paper. Cost analysis has been carried out with optimum value of 30% CFEA in 1:3 proportions of flaky and elongated particles.

1

is mainly depends on the rock formation and type of crusher being used for crushing the aggregates. The most commonly used crushers in India are primary and secondary jaw crusher, using which, it is difficult to control flaky and elongated particles within the specified limits. 1.1

Shape Test

(i)

Flakiness Index: - The flakiness index of aggregate is percentage by the weight of particles whose least dimension (thickness) is less than three-fifths (0.6) of their mean dimension. The taste is not applicable to sizes smaller than 6.3 mm.

(ii)

Elongation Index: - Elongation index of an aggregate is the percentage by the weight of particle whose greatest dimension (length) is greater than one and four fifth times (1.8 times) their mean dimension. The elongation test is not applicable to sizes smaller than 6.3 mm.

2

Objectives of the Study

Introduction

India has a total road network of about 3.3 million km. Road as one of the surface transportation infrastructures is very important in supporting the economic for both regional and national development. About 80 percent of the total volume of concrete consists of aggregate. Aggregate characteristics significantly affect the performance of fresh and hardened concrete and have an impact on the cost effectiveness of concrete. Aggregate characteristics of shape, texture, and grading influence workability, finishability, bleeding, pumpability and segregation of fresh concrete and affect strength, shrinkage, creep, density, permeability, and durability of hardened concrete. Construction and durability problems have been reported due to poor mixture proportioning and variation on grading. Flaky and elongated particles lead to higher voids than, cubical, rounded and well graded particles. The shape factor of aggregate plays a vital role in the design and performance of concrete mix and it

*

Research Scholar, MANIT, Bhopal

**

Associate Professor, SGSITS, Indore

INDIAN HIGHWAYS, March 2013

This study has been done for following objectives: (i)

To find out properties of aggregate such as, bulk density, impact value, crushing value and water absorption, with different proportions of CFEA (1:3, 1:1 & 3:1) and percentage of CFEA (0 to 50 %).

(ii)

To study the properties of concrete mixes for PQC in the laboratory at varying combined flakiness & elongation aggregate.

35

TECHNICAL PAPERS (iii) To find out optimum proportion of combined flakiness and elongation aggregate. (iv) To study the cost analysis for optimum value of CFEA.

Table 4.1 Observed Cement Properties Normal Consistency of Cement 28%

3

EXPERIMENTAL WORK

The aggregates were collected from Jaw Crusher at Devguradiya Distt. Indore. Then flaky and elongated particles are separate in laboratory. The properties of cement, such as compressive strength and setting time, were tested (Table 4.1). All in grading for coarse and fine aggregates is shown in Table 4.2. The aggregates were characterized for their properties such as, bulk density, impact value, crushing value and water absorption (Table 4.3 to Table 4.6), with different proportions of CFEA. General properties of aggregate like specific gravity, flakiness index and elongation index are shown in Table 4.7. Properties of aggregate, for 30% CFEA, are given in Table 4.8. To prepare the specimen of combined flakiness and elongation aggregates (CFEA) of 0, 10, 20, 30, 40 and 50% in which flaky and elongated particles mixed in proportions 1:3, 1:1 and 3:1.To prepare specimens (beam & cube) for each proportions for M-30 and M-40 grade of concrete, keeping 0.42 and 0.40 watercement ratios respectively, with superplasticizer 1% by weight of cement. 4

TEST RESULTS AND ANALYSIS

4.1

Cement Testing

Cement has been tested for the following tests as per the code provisions mentioned. ●

Normal consistency (IS 269-1967)



Compressive strength (IS 269-1967)



of

cement

Setting time of Cement

7 Days

28 Days

Initial

Final

32.30

45.16

120 min.

180 min.

The 43 grade Ordinary Portland Cement is used in the study the 28 days compressive strength is more than required strength. The specific gravity of cement is 3.15. 4.2

Sieve Analysis

All in grading, as per IS: 383:1970, shown in Table 4.2 Table 4.2 ALL-IN-GRADING

4.3

IS Sieve

% Passing

Limits

40 mm

100

100

20 mm

96.1

95-100

4.75 mm

48.05

30-50

600 µ

10

10-35

150 µ

0

0-6

Properties of Aggregate

Properties of aggregate such as, bulk density, impact value, crushing value and water absorption, for different proportions and different % of CFEA, are given in Table 4.3 to 4.6. Table 4.3 Bulk Density for Different Proportions and Different % of CFEA BULK DENSITY (kg/m3)

mortar

Setting time of cement (IS 269-1967)

Summary of the values observed for the chosen cement with regard to the above listed test are being presented in Table 4.1 36

Compressive Strength of Cement Mortar

Proportions of CFEA

% of CFEA 0

10

20

30

40

50

1:3

1586

1558

1534

1511

1478

1428

1:1

1586

1563

1544

1527

1498

1457

3:1

1586

1568

1553

1537

1512

1473

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS Table 4.4 Impact Value for Different Proportions and Different % of CFEA

Table 4.8 Properties of Aggregate for 30% CFEA

Properties

Test value

Impact value,%

11.42

Crushing value,%

18.31

Water absorption,%

0.48

Bulk density, kg/ m3

1511

IMPACT VALUE (%) Proportions of CFEA

% of CFEA 0

10

20

30

40

50

1:3

10.12

10.46

10.89

11.42

12.04

12.71

1:1

10.12

10.51

10.97

11.53

12.15

12.88

3:1

10.12

10.48

11.04

11.67

12.38

13.16

Table 4.5 Crushing Value for Different Proportions and Different % of CFEA

Testing of Hardened Concrete

Properties of Cement Concrete Compressive strength of concrete of different proportions of CFEA for M-30 is given in Table 4.9 to 4.11.

CRUSHING VALUE (%) Proportions of CFEA

4.4

% of CFEA 0

10

20

30

40

50

1:3

17.68

17.94

18.12

18.31

18.63

19.42

1:1

17.68

18.08

18.40

18.72

19.09

20.04

3:1

17.68

18.17

18.54

19.11

19.74

21.06

Table 4.9 Compressive Strength of 1:3 Proportions for M-30 Grade of Concrete

Proportions of CFEA

% of CFEA

7 Days

28 Days

0

28.08

40.12

10

26.16

37.38

20

26.53

37.73

30

26.86

38.38

40

25.77

36.95

50

25.69

36.70

Table 4.6 Water Absorption for Different Proportions and Different % of CFEA WATER ABSORPTION (%) Proportions of CFEA

% of CFEA 0

10

20

30

40

50

1:3

0.34

0.36

0.42

0.48

0.55

0.64

1:1

0.34

0.39

0.45

0.51

0.59

0.67

3:1

0.34

0.43

0.49

0.57

0.65

0.72

The general properties of aggregate material are given in Table 4.7. Table 4.7 General Properties of Aggregate Material Properties

Test value

Specific gravity

2.78

Flakiness index,%

17.16

Elongation index,%

12.63

The properties of aggregate for 30% CFEA are given in Table 4.8. INDIAN HIGHWAYS, March 2013

M 30

1:3

Avg. Comp. Strength (MPa)

Table 4.10 Compressive Strength of 1:1 Proportions for M-30 Grade of Concrete

M 30

Proportions of CFEA

1:1

% of CFEA

Avg. Comp. Strength (MPa) 7 Days

28 Days

0

28.08

40.12

10

25.80

36.86

20

25.93

37.05

30

26.53

37.90

40

25.70

36.72

50

25.61

36.50

37

TECHNICAL PAPERS Table 4.14 Flexural Strength of 3:1 Proportions for M-30

Table 4.11 Compressive Strength of 3:1 Proportions for M-30 Grade of Concrete

M 30

Proportions of CFEA

3:1

% of CFEA

Avg. Comp. Strength (MPa)

Grade of Proportions of % of Flexural Strength Concrete CFEA CFEA (MPa) 7 Days

28 Days

0

3.80

4.40

10

3.08

3.70

20

3.14

3.74

37.37

30

3.39

3.94

25.56

36.52

40

2.80

3.40

25.37

36.24

50

2.66

3.27

7 Days

28 Days

0

28.08

40.12

10

25.65

36.34

20

25.77

36.60

30

26.16

40 50

M 30

3:1

Flexural strength of concrete of different proportions of CFEA for M-30 is given in Table 4.12 to 4.14.

Compressive strength of concrete of different proportions of CFEA for M-40 is given in Table 4.15 to 4.17.

Table 4.12 Flexural Strength of 1:3 Proportions for M-30

Table 4.15 Compressive Strength of 1:3 for M-40

Grade of Concrete

M 30

Proportions of CFEA

1:3

% of CFEA

Flexural Strength (MPa)

Grade of Proportions of % of Concrete CFEA CFEA

7 Days

28 Days

0

39.97

57.10

10

39.12

55.89

20

39.24

56.06

4.3

30

39.63

56.47

3.2

3.84

40

39.02

55.74

3.05

3.72

50

38.91

55.59

7 Days

28 Days

0

3.8

4.4

10

3.22

3.88

20

3.43

3.96

30

3.78

40 50

M 40

M 30

38

Proportions of CFEA

1:1

% of CFEA

1:3

Table 4.16 Compressive Strength of 1:1 Proportions for M-40

Table 4.13 Flexural Strength of 1:1 Proportions for M-30 Grade of Concrete

Avg. Comp. Strength (MPa)

Flexural Strength (MPa)

Grade of Proportions of % of Concrete CFEA CFEA

Avg. Comp. Strength (MPa) 7 Days

28 Days

0

39.97

57.10

10

37.38

53.41

20

37.66

53.80

30

38.02

54.32

3.60

40

37.24

53.20

3.45

50

37.08

52.98

7 Days

28 Days

0

3.80

4.40

10

3.14

3.79

20

3.28

3.82

30

3.60

4.12

40

2.04

50

2.88

M 40

1:1

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS Table 4.17 Compressive Strength of 3:1 Proportions for M-40

Table 4.20 Flexural Strength of 3:1 Proportions for M-40

Grade of Proportions % of Avg. Comp. Strength Concrete of CFEA CFEA (MPa)

M 40

28 Days

0

4.95

5.90

10

4.10

4.90

20

4.27

4.97

51.78

30

4.63

5.17

34.40

50.14

40

3.95

4.8

34.24

49.92

50

3.76

4.57

28 Days

0

39.97

57.10

10

34.92

50.89

20

35.10

51.14

30

35.55

40 50

Flexural strength of concrete of different proportions of CFEA for M-40 is given in Table 4.18 to 4.20. Table 4.18 Flexural Strength of 1:3 Proportions for M-40 Proportions of CFEA

M 40

1:3

% of CFEA

Flexural Strength (MPa) 7 Days

28 Days

0

4.95

5.9

10

4.35

5.21

20

4.53

5.33

30

4.94

5.64

40

4.25

5.15

50

4.1

5.01

Table 4.19 Flexural Strength of 1:1 Proportions for M-40 Grade of Concrete

Proportions of CFEA

% of CFEA

Flexural Strength (MPa) 7 Days 28 Days

M 40

1:1

Flexural Strength (MPa) 7 Days

7 Days

3:1

Grade of Concrete

Grade of Proportions % of Concrete of CFEA CFEA

0

4.95

5.90

10

4.20

5.07

20

4.38

5.13

30

4.73

40 50

M 40

3:1

On the basis of above given data (Table 4.9 to 4.20) it is observed that 30% of CFEA give more strength, both compressive and flexural strength. Due to more surface of flaky and elongation aggregate the water absorption also increase. There are need more mortar paste in concrete mix. So increase 3% & 1.5% extra cement of total cement content for M-30 & M-40 respectively and find out 28 days compressive strength for 30% CFEA given in Table 4.21 & 4.22. Table 4.21 28 Days Compressive Strength (MPa) of M-30 for 30% CFEA with 3% Extra Cement of Total Cement Content Per m3 Proportions of CFEA

Normal Cement Content

3% extra Cement

1:3

38.38

40.20

1:1

37.90

39.51

3:1

37.37

39.32

Table 4.22 28 Days Compressive Strength (MPa) of M-40 for 30% CFEA with 1.5% Extra Cement of Total Cement Content Per m3 Proportions

Normal Cement Content

1.5% extra Cement

5.34

1:3

56.47

57.35

4.08

4.95

1:1

54.32

55.32

3.91

4.78

3:1

51.79

53.27

INDIAN HIGHWAYS, March 2013

39

TECHNICAL PAPERS 4.5

Cost Analysis

Table 4.26 Cost (Rs.) Difference for PQC in per m3 for M-30

Cost analysis for PQC are shown from Table 4.23 to Table 4.23 Cost Calculation of PQC for Normal Cement Content of Total Cement Content with Aggregate Produced by Jaw Crusher for M-30 Material Quantity

Rate in Rs./m3 245/bag 725 500

Cement 380 Sand 631 Aggregate 1254 Water, mixing, placing Total cost Contractor profit @10% Grand total

Volume, m3 7.6 bags 0.375 0.830

Cost in Rs./m3 1862 272 415 350 2899 290 3189

Table 4.24 Cost Calculation of PQC for Extra 3% Cement of Total Cement Content with Aggregate Produced by Jaw Crusher for M-30 Material Quantity Cement

391.4

Sand 649.72 Aggregate 1291.62 Water, mixing, placing Total cost Contractor profit @10% Grand total

Rate in Rs./m3 245/bag 725 500

Volume, m3 7.828 bags 0.387 0.855

Cost in Rs./m3 1918 281 427 350 2976 297 3273

Extra 3% Cement Content

VSI product

Cost diff. Rs./m3

%of cost saving

3273

3575

302

8.45%

Table 4.27 Cost Calculation of PQC for Normal Cement Content of Total Cement Content with Aggregate Produced by Jaw Crusher for M-40 Material

Quantity in kg

Rate in Rs./m3

Volume, m3

Cost in Rs./m3

Cement

410

245/bag

8.2 bags

2009

Sand

619

725

0.368

267

Aggregate

1230

500

0.814

407

Water, mixing, placing

350

Total cost

3033

Contractor profit @10%

303

Grand total

3336

Table 4.28 Cost Calculation of PQC for Extra 1.5% Cement of Total Cement Content with Aggregate Produced by Jaw Crusher for M-40 Material Quantity

Table 4.25 Cost Calculation of PQC for Normal Cement Content of Total Cement Content with Aggregate Produced by Vertical Shaft Impector (VSI) Crusher for M-30 Material

Quantity Rate in Rs./m3 Cement 380 245/bag Sand 631 725 Aggregate 1254 950 Water, mixing, placing Total cost Contractor profit @10% Grand total

40

Volume, m3 7.6 bags 0.375 0.806

Cost in Rs./m3 1862 272 766 350 3250 325 3575

Rate in Rs./m3

Volume, m3

Cost in Rs./m3

Cement

416.15

245/bag

8.323 bags

2039

Sand

628.38

725

0.374

271

Aggregate 1248.45

500

0.826

413

Water, mixing, placing

350

Total cost

3073

Contractor profit @10%

309

Grand total

3380

INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS Table 4.29 Cost Calculation of PQC for Normal Cement Content of Total Cement Content with Aggregate Produced by VSI Crusher for M-40 Material Quantity

Rate in Rs./m3

Volume, m3

Cost in Rs./m3

Cement

410

245/bag

8.2 bags

2009

Sand

619

725

0.368

267

Aggregate

1230

950

0.791

751

Water, mixing, placing

350

Total cost

3377

Contractor profit @10%

338

Grand total

3715

Table 4.30 Cost (Rs.) Difference for PQC in per m3 for M-40 Extra 1.5% VSI product Cement Content 3380

5

Properties of Cement Concrete 1.

At 10% CFEA interlocking of aggregate is less. So strengths are decreased.

2.

At 20% CFEA interlocking of aggregate is extended. So strengths are increased as compared to 10% CFEA.

3.

At 30% CFEA maximum interlocking of aggregate is arise. So strengths are maximum.

4.

More than 30% CFEA apart from interlocked excess. Flaky and elongated particles are present in the mix and when load comes on the concrete the excess particles break at lower load. So the strengths achieved less for more than 30% CFEA.

Properties of Aggregate

Cost diff. Rs./m3

%of cost saving

1.

Flaky and elongated particles do adverse affect the material properties, however, this effect gets increased beyond 30% CFEA.

335

9.02%

2.

Percentage reduction in bulk density is less with inclusion of flaky particles as compared to elongated particles.

3.

Percentage increase in impact value, crushing value, and % water absorption is more with flaky particles as compared to elongated particles.

4.

Therefore at 30% CFEA with 1:3 proportions of flaky and elongated particle, a combination of above properties results in minimum reduction in compressive and flexural strength as compared to 0% CFEA.

6

CONCLUSIONS

1.

The maximum compressive and flexural strength for PQC mix is observed at 30% CFEA, having flaky and elongated particles in proportions of 1:3.

2.

Flaky particles have more adverse effect on crushing value, impact value and % water absorption, whereas elongated particles have on bulk density. All these adverse effects

3715

DISCUSSIONS

Based on present study following facts are discussed: 1.

Properties of cement concrete

2.

Properties of Aggregate

Fig 5.1 Interlocking Between Aggregates with Different % of CFEA

INDIAN HIGHWAYS, March 2013

41

TECHNICAL PAPERS increase rapidly after 30% CFEA. Therefore, a combination of above properties with 30% CFEA and 1:3 proportions of flaky and elongated particles, results in minimum reduction in compressive and flexural strength. 3.

4.

5.

By addition of 3% and 1.5% extra cement of total cement content per m3 in M-30 and M-40 grades of concrete respectively, made with 30% CFEA, the strength of concrete made with 0% CFEA is achieved. The addition of extra 3% cement in Concrete made with aggregate produced by Jaw crusher reduces the cost of M-30 grade of concrete made with aggregate produced by VSI crusher by 302 Rs. / m3, i.e. 8.45% of total cost. The addition of extra 1.5% cement in Concrete made with aggregate produced by Jaw crusher reduces the cost of M-40 grade of concrete made with aggregate produced by VSI crusher by 335 Rs. / m3, i.e. 9.02% of total cost.

9.

IS: 2386 (Part IV)-1963, “Methods of Test for Aggregates for Concrete- Mechanical Properties”, Bureau of Indian Standards.

10.

Khanna, S.K. and Justo, C.E.G. (2010) “Highway Engineering”, Nem Chand & Bros, Roorkee (U.A.)

11.

Nagendra, R., Dhabale, A., Sharada Bai, H., and Rajeeva, S., (2006), “Analysis of Shape Parameters of Coarse Aggregate and their Effect on Packing Density by DIP Technique” Indian Concrete Journal ,vol.80 , 29-38

12.

Pradhan Ajit and Banerjee Sandeep (2000), “Selection of Aggregate Crushing Plants for Road Projects-Techno Economic Aspects”, Indian Concrete Journal, vol.76, Number 2, 123-129.

13.

Ramanaiah, C., Wong, C.Y., and Mukherjee P. (2000), “Control of Flakiness and Elongation Indices with Selection of Crusher Type”, Highway Research Bulletin, Number 62, pp. 37-47.

14.

Sengupta, J.B. and Kumar S., (2008), “Effect of Flakiness Indices on the Properties of Aggregate and Concrete”, Indian Highways, pp. 57-62.

REFERENCES 1.

Bouquety, M., N., Descantes, Y., Barcelo, L., De Larrard, F., and Clavaud B., (2006), “Automated Measurement of Aggregate Properties: Part 2-Flakiness Index”, Journal of Materials and Structures, vol.39, pp.13-19.

2.

IRC: 44-2008, “Tentative Guidelines for Cement Concrete Mix Design for Pavements”, Indian Roads Congress.

3.

IS: 10262-2009, “Indian Standard Recommended Guidelines for Concrete Mix Design”, Bureau of Indian Standards.

4.

IS: 383-1970, “Specification for Coarse and Fine Aggregates From Natural Sources for Concrete”, Bureau of Indian Standards.

5.

IS: 516-1959, “Methods of Tests for Strength of Concrete”, Bureau of Indian Standards.

6.

IS:SP:23, “Hand Book on Concrete Mixes”, Bureau of Indian Standards.

7.

IS: 2386 (Part I)-1963, “Methods of Test for Aggregates for Concrete- Particle Size and Shape”, Bureau of Indian Standards.

8.

IS: 2386 (Part III)-1963, “Methods of Test for Aggregates for Concrete- Specific Gravity, Density, Voids, Absorption and Bulking”, Bureau of Indian Standards.

42

INDIAN HIGHWAYS, March 2013

NANOTECHNOLOGY IN HIGHWAY ENGINEERING Y.C. Tewari* and R.S. Bharadwaj**

Abstract Nanotechnology deals with understanding, controlling, and manipulating matter at the level of individual atoms and molecules in the range of 0.1–100 nm (10-9m) and creating materials, devices, and systems with new properties and functions. The construction sector can benefit from these advances in nanotechnology because materials are the core elements in construction. By significantly improving the performance of sensors and data acquisition systems and reducing their sizes, nanotechnology can also enable the practical deployment of structural health monitoring systems for large civil infrastructure systems and provide vital tools to design an innovative civil infrastructure and facilitate the practice of managing and protecting the civil infrastructure. In this paper, the innovation of relevant nanotechnology and its impact on highway engineering practice is introduced for broadening vision and inspiring the creativity of highway engineering.

1

Introduction

Nanotechnology, introduced almost half century ago, is one of the most active research areas with both novel science and useful applications that has gradually established itself in the past two decades. The evolution of technology and instrumentation as well as its related scientific areas such as physics and chemistry are making the research on nanotechnology aggressive and evolutional. The bulk properties of materials often change dramatically with nano ingredients. Composites made from particles of nanosize ceramics or metals smaller than 100 nanometers can suddenly become much stronger than predicted by existing materials-science models.1 For example, nanotubes are very strong–one of the strongest materials we know of. A carbon nanotube is one atom thick sheet of graphite rolled up into a seamless cylinder with diameter of the order of nanometer (Fig. 1).

*

Principal Scientist,

**

Senior Principal Scientist,

Fig. 1 A Plane of Graphite (left) Rolled up (middle) Gives a Nanotube (right), Matching Points A with A’, B with B’ and so Forth

Nanotubes are many times stronger than steel, yet lighter. They are also more resistant to damage; that is, they are highly elastic. Nanotubes can be bent to surprisingly large angles before they start to ripple, buckle, or break. Even severe distortions won’t break them (Fig. 2).

Fig. 2 A Severely Distorted Nanotube Still Doesn’t Break

Table 1, below, shows the Young’s Modulus, tensile strength, and density of nanotubes compared to other common materials. (GPa stands for gigapascals.) For example, wood is very light (low density) but weak (low Young’s Modulus and low tensile strength), while nanotubes are many times stronger than steel (nanotubes have a higher Young’s Modulus and much

CSIR - Central Road Research Institute, New Delhi

INDIAN HIGHWAYS, March 2013

43

TECHNICAL PAPERS higher tensile strength) and yet much lighter (lower density). Nanotubes also have higher tensile strength even than diamond and a similar (slightly lower) elasticity, and yet they are half as dense. Table 1 Comparison of Mechanical Properties of Various Materials Material

Young’s Modulus (GPa)

Tensile Strength (GPa)

Density (g/cm3)

Single wall nanotube

~800

>30

1.8

Multi wall nanotube

~800

>30

2.6

Diamond

1140

>20

3.52

Graphite

8

0.2

2.25

Steel

208

0.4

7.8

Wood

16

0.008

0.6

2

APPLICATION IN CONCRETE

Plain concrete itself is a brittle material that is much stronger in compression than in tension. Carbonnanotubes may be applied to improve mechanical performance of cement/cabon-nanotube composite. It has also been reported that adding small amount of carbonnanotube (1%) by weight could increase both compressive and flexural strength.2 Cracking is a major concern for many structures. University of Illinois Urbana-Champaign is working on healing polymers, which include a microencapsulated healing agent and a catalytic chemical trigger. When the microcapsules are broken by a crack, the healing agent is released into the crack and contact with the catalyst. The polymerization happens and bond the crack faces (Fig. 4). The self healing polymer could be especially applicable to fix the microcracking in bridge piers and columns.

Addition of nanoscale materials into cement could improve its performance. Use of nano-SiO2 could significantly increase the compressive strength for concrete, containing large volume fly ash, at early age and improve pore size distribution by filling the pores between large fly ash and cement particles at nanoscale (Fig. 3). The dispersion/slurry of amorphous nanosilica is used to improve segregation resistance for self-compacting concrete.

Fig. 4 Self-healing Concept for a Thermosetting Polymer

3

Fig. 3 Evidence of Reinforcing Mechanisms of CNT in Cement

44

APPLICATION IN ASPHALT

The mechanical behavior of bituminous materials depends to a great extent on structural elements and phenomena which are effective on a micro- and nanoscale. The basic concept behind nano modification of INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS materials is that of “bottom-up” engineering, starting with engineered modifications to the molecular structure with an aim to affect the bulk properties of the material. The nano-modification of bituminous materials has the potential to open up whole new uses and classes of bituminous materials, with wide-ranging implications for the transportation infrastructure. The ability to target material modification at the nanostructural level promises to deliver the optimization of material behavior and performance needed to significantly improve mechanical performance, durability, reflectivity and skid resistance, better binding, quicker curing, better maintenance and sustainability. Currently IntegraBase is the only asphalt modifiers available in the market that work on a nano-scale. The majority of products that are used with asphalts are simply additives, which don’t do anything to the chemistry of the asphalt, rather just improving specific properties such as binding, flexibility, etc. IntegraBase is a catalyst which, unlike polymer additives, reacts with bitumen and changes the chemistry and the molecular structure of the bitumen under the influence of temperature and oxygen. This catalytical reaction results in the formation of ketones at the most reactive sites within the bitumen molecules, thereby greatly reducing the bitumen’s susceptibility to oxidative ageing, and improving its anti-stripping properties. In a second consecutive phase, the organo-metallic components of the IntegraBase modifier will react with the ketones, producing strong, irreversible bonds between the bitumen molecules, resulting in a bitumen with highly reduced temperature susceptibility. The formation of ketones can be demonstrated by infrared spectroscopy. The ketones found in bitumen characteristically absorb light in the spectral region defined by wave numbers around 1690 cm-1. The comparison of the relative levels of absorbance for INDIAN HIGHWAYS, March 2013

conventional bitumen and IntegraBase modified bitumen in this spectral region confirms that a very significant amount of ketones is formed in the IntegraBase bitumen, while only a small amount of ketones is evident in the unmodified bitumen (Fig. 5).

Fig. 5 Infrared Spectra of Unmodified Bitumen and Integra Base Modified Bitumen

4

APPLICATION IN STEEL

Steel has been widely available material and has a major role in the construction industry. The use of nanotechnology in steel helps to improve the properties of steel. The current steel designs are based on the reduction in the allowable stress, service life or regular inspection regime. This has a significant impact on the life-cycle costs of structures and limits the effective use of resources. The Stress risers are responsible for initiating cracks from which fatigue failure results. The addition of copper nano particles reduces the surface un-evenness of steel which then limits the number of stress risers and hence fatigue cracking. Advancements in this technology using nano particles would lead to increased safety, less need for regular inspection regime and more efficient materials free from fatigue issues for construction. It is possible to develop new, low carbon, High Performance Steel (HPS) with higher corrosionresistance and weld ability by incorporating copper nano particles from at the steel grain boundaries (Fig. 6).

45

TECHNICAL PAPERS at would result in a smaller resource requirement because less material is required in order to keep stresses within allowable limits. The carbon nanotubes are exciting material with tremendous properties of strength and stiffness, they have found little application as compared to steel, because it is difficult to bind them with bulk material and they pull out easily, Which make them ineffective in construction materials.3,4 5 Fig. 6 Copper Nano Particles at the Steel Grain Boundaries

The nano-size steel produce stronger steel cables which can be used in bridge construction. Also these stronger cable material would reduce the costs and period of construction, especially in suspension bridges as the cables are run from end to end of the span. This would require high strength joints which leads to the need for high strength bolts. The capacity of high strength bolts is obtained through quenching and tempering. The microstructures of such products consist of tempered martensite. When the tensile strength of tempered martensite steel exceeds 1,200 MPa even a very small amount of hydrogen embrittles the grain boundaries and the steel material may fail during use. This phenomenon, which is known as delayed fracture, which hindered the strengthening of steel bolts and their highest strength is limited to only around 1,000 to 1,200 MPa. The use of vanadium and molybdenum nano particles improves the delayed fracture problems associated with high strength bolts reducing the effects of hydrogen embrittlement and improving the steel micro-structure through reducing the effects of the inter-granular cementite phase. Welds and the Heat Affected Zone (HAZ) adjacent to welds can be brittle and fail without warning when subjected to sudden dynamic loading. The addition of nano particles of magnesium and calcium makes the HAZ grains finer in plate steel and this leads to an increase in weld toughness. The increase in toughness

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SELF-CLEANING MATERIALS: LOTUS LEAF-INSPIRED NANOTECHNOLOGY

The story of self-cleaning materials begins in nature with the sacred lotus (Nelumbo nucifera), a radiantly graceful aquatic perennial that has played an enormous role in the religions and cultures of India, Myanmar, China and Japan. The lotus is venerated because of its exceptional purity. It grows in muddy water, but its leaves, when they emerge, stand meters above the water and are seemingly never dirty. Drops of water on a lotus leaf have an unearthly sparkle, and rainwater washes dirt from that leaf more readily than from any other plant. Microscopic bumps on a lotus leaf transform its waxy surface into an extremely water repellent, or super hydrophobic, material. Raindrops roll easily across such a surface, removing any dirt.5 Researchers have developed synthetic self-cleaning materials, some of which are based on this “lotus effect,” whereas others employ the opposite property—super hydrophilicity—as well as catalytic chemical reactions. The lotus effect exterior coating or paint on traffic signs requires no labor intensive or periodic washing or remove road grim and enhances visibility and safety. In terms of the usage of the facility, visibility is one aspect where the application of nanotechnology is already showing promise. This is through the improvement of the materials used for the application of signage to the facility, or the incorporation of the signage into the facility through the application of materials such as nanophosphors (Fig. 7). Current work in regard shows promise in terms of rendering infrastructure surfaces autoluminescent, thereby providing guidance to traffic at night.6 INDIAN HIGHWAYS, March 2013

TECHNICAL PAPERS power and cost optimized. Using multi-hop techniques, the data of the sensor network has to be transmitted over short distances of some 10 m to a base station on site. There the data items are collected and stored in a data base for subsequent analysis. This data can then be accessed by a remote user. If the central unit detects a hazardous condition by analyzing the data, it raises an alarm message. Each mote is composed of one or more sensors, a data acquisition and processing unit, a wireless transceiver and a battery as power supply. The acquisition and processing unit usually is equipped with a low power microcontroller offering an integrated Analogue to Digital Converter (ADC) and Sufficient Data Memory (RAM) to store the measurements. This unit also incorporates signal conditioning circuitry interfacing the sensors to the ADC.7 Fig. 7 Self Cleaning Nano Coating on Traffic Sign

6

NANO SENSORS

It is reported that the feasibility of Cyberliths, or Smart Aggregates, as wireless sensors embedded in concrete is being evaluated. In the future these micro sensors might be reduced to dust-particle size, with the ability to coat an entire bridge with Smart Dust for optimum monitoring capabilities via a smart sensor net. These sensors can be used to remotely monitor the condition of the concrete and reinforcement without damaging the structures. MEMS (Micro-Electro-MechanicalSystems) sensors have been developed and installed on structures. These sensors do not constitute nano technology, but they do illustrate use of embedded sensors and give an indication of what can be accomplished in the future as the nanotechnology reduces the sensor size. Monitoring systems using traditional wired sensor technologies and several other devices are time consuming to install and relatively expensive. A wireless monitoring system with MEMS (MicroElectro-Mechanical-Systems) sensors could reduce these costs significantly. MEMS are small integrated devices or systems that combine electrical and mechanical components. The principle of such a system is shown in the scheme given in Fig. 8. Each sensor device (mote), which is itself a complete, small measurement and communication system, has to be INDIAN HIGHWAYS, March 2013

Fig. 8 Scheme for Wireless Sensing of Large Structures Using Radio Frequency Transmission Techniques and MEMS

7

ECONOMICAL ASPECTS

The use of nano technology will also potentially affect the economical aspects of infrastructure provision for transportation. Though the cost of the nano materials is high, the benefits that can be obtained through the application of stronger materials should ultimately result in the decrease for the amount of material (i.e. thinner concrete layers for pavements) affecting the construction cost. Obviously, the lifecycle effects in terms of durability and expected maintenance requirements of the material should be included in any cost evaluation. The general service life of infrastructure can be increased through the improvement of the resistance of the infrastructure to environmental effects. In this regard the various types of nano-composite coatings that can be applied to concrete surfaces (i.e. bridge abutments and pillars) is an example of prolonging the life of the facility. Most of these coatings differ from traditional 47

TECHNICAL PAPERS coatings in terms of the way in which they bond to the substrate material, providing a more robust layer that binds chemically with the substrate.   The incorporation of sensing elements that can provide timely indications of changes in the properties of infrastructure materials to ensure timely maintenance is another area where potential developments may cause cost savings. However, most of the work in this regard (on a nanoscale) is currently performed in the areas of biological and chemical sensors, and further developments will be required to obtain realistic systems. 8

CONCLUSIONS

Although the cost of nanotechnology-enabled materials and devices may hinder their widespread application for highway engineering at the current stage, their price is expected to drop in the near future. In addition, the benefits from nanotechnology’s application could justify the additional cost. However, the useful improvements that nanotechnology might bring to highway infrastructure could be minimized

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if highway engineering professionals lack appropriate vision and awareness of potential nanotechnology applications for highway engineering. 9

REFERENCES

1.

http://en.wikipedia.org/wiki/Nanotechnology

2.

Balaguru, P. N. (2005), “Nanotechnology and Concrete: Background, Opportunities and Challenges.” Proceedings of the International Conference – Application of Technology in Concrete Design , Scotland, UK, p.113-122.

3.

Ar.Mohd.Firoz Anwar(2009) “nanotechnology and its Impact on Architecture” March 2009 IIA Journal Article.

4.

Ar.S.M.Noman tariq (2010) “The Nano Revolution In Architectural World”

5.

November 2010 NBM&CW (Vol.16,Issue-5)

6.

NanoArchitecture, Maged Elsamny thesis, Faculty of Engineering, University of Alexandria.

7.

Roco, M. C. (2002). “Nanotechnology—A Frontier for Engineering Education.” Int. J. Eng. Educ., 18(5), 488–497.

8.

Tewari, Y.C. (2011), Health Monitoring of Civil Structures” Diamond Jubilee Year Souvenir CSIR-CRRI, July 16, 2011.

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Comparison between Coarse Aggregate Shape Factors and Resulting Mix Properties using Conventional and New Universal Gauge Instruments Dr. Mohamed Ilyas Anjum* Abstract The aggregate shape factors such as flakiness, elongation separately dealing with thickness and length respectively, as well as in combination and angularity number play a vital role in the properties of resulting granular as well as bituminous mixes. These properties are determined using a set of IS sieves such as 50, 40, 31.5, 25, 20, 16, 12.5, 10 and 6.3 mm and based on this the upper limits for their presence in mixes have been specified. However, in mixes, the aggregate gradation consists of sieves such as 26, 19.5, 11.2 mm etc. This indicates that sieves used for shape factors determination and actual use are different which needs rethinking. It is expected that the shape factors and mix properties determined by the conventional sieves, instruments may be different from those determined using actual sieves. It was therefore attempted to design and fabricate a single, simple and inexpensive new instrument, referred in the paper as Universal Gauge, to determine the aggregate sizes and compare with those determined by conventional instruments. It was also attempted to compare the Marshall test properties of Semi Dense Bituminous Concrete mixes using the same aggregate with shape factors determined by the two approaches separately. It was found that the results obtained from the two approaches are different.

1

Index (C.I) which is the sum of F.I and E.I determined separately. The shape factors can be determined using the standard length and thickness gauge which caters to only few aggregate sizes. Hence it is necessary to device a new instrument which can cater to a wide range of aggregate sizes in view of frequent changes made in the gradation requirements of coarse aggregates in bituminous mixes. The objectives of the present study, therefore, are 1.

To fabricate a new instrument referred as universal gauge to determine the aggregate shape factors such as F.I, E.I and C.I using the new instrument.

2.

To compare the shape factors and resulting mix properties determined using the conventional and the new instruments.

2

Experimental work

2.1

Determination of Flakiness Index

Introduction

The aggregate shape factors are evaluated in terms of Flakiness Index (F.I), Elongated Index (E.I) and Angularity Number (AN). The suitability of aggregate for use in road construction is based on satisfaction of several requirements in general and resistance to impact, crushing and abrasion in particular. These properties are influenced by several factors such as type of aggregate, its size, its shape, gradation, specific gravity etc. IS 2386 part I 1964 has laid down the standard procedure for determination of aggregate shape factors such as F.I, E.I and AN. However, the MOST in its Specifications for Road and Bridge Work, 1998 suggested a slightly different approach to determine E.I and brought in the concept of Combined

*

The F.I was determined as per the procedure laid down by IS 2386 part I. The aggregate were sieved into fractions such as 25-20, 20-16, 16-12.5, 12.5-10 and 10-6.3 mm using a coarse aggregate mechanical sieve shaker. The specific gravity and water absorption of aggregate in each fraction were determined as per IS 2386 part III. The weight of aggregate in each fraction was found by using an electronic balance. Using the conventional thickness gauge shown in Fig.1, each aggregate in the first fraction was passed along its thickness through the respective opening. The flaky aggregate passing through respective opening were separated and weighed. Similarly weights of flaky

Prof. & HoD, Department of Civil Engineering, Ghousia College of Engineering, Ramanagaram, Karnataka, E-mail: [email protected]

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TECHNICAL PAPERS aggregate in the other fractions were determined. The F.I was calculated as the ratio of weight of flaky aggregate in each fraction to total weight of aggregate sample in each fraction expressed as a percentage.

referred as universal gauge shown in Fig.3, developed at Department of Civil Engineering of Ghousia college of Engineering. In the new instrument, there is provision for adjusting the opening to any desired size. To determine the shape factors using the universal gauge the gradation of semi dense bituminous concrete as per MoRTH presented in Table.1 was used.

Fig. 1 Conventional Thickness Gauge

2.2

Determination of Elongation Index

The EI was determined as per procedure laid down by IS 2386 part I and MoRTH. Using the conventional length gauge shown in Fig.2, each aggregate in the first fraction, after separating the flaky aggregates, was passed along its length through respective opening. The elongated aggregate retained on the respective opening was separated and weighed. Similarly the weights of elongated aggregate in the other fractions were determined. The F.I and E.I so determined were added to get the respective C.I. The weighted average F.I, E.I and C.I of the sample was then calculated.

Fig.2 Conventional Length Gauge

2.3

Determination of F.I and E.I using the Universal Gauge

The same aggregate sample was then used and the F.I, E.I and C.I were determined using the new instrument 50

Fig. 3 Universal Gauge

Table 1 Composition of Semi Dense Bituminous Concrete Pavement Layers as per MoRTH Grading

1

2

Nominal aggregate size

13 mm

10 mm

Layer Thickness

35-40 mm

25-30 mm

IS Sieve(mm)

Cumulative % by weight of total aggregate passing

Cumulative % by weight of total aggregate passing

45 37.5 26.5 19 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075

100 90-100 70-90 35-51 24-39 15-30 9-19 3-8

100 90-100 35-51 24-39 15-30 9-19 3-8

Bitumen content % by mass of total mix

Min 4.5

Min 5.0

Bitumen grade (pen)

65

65

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TECHNICAL PAPERS 2.4

Determination of Angularity Number

The Angularity Number was determined as per the procedure laid down by IS 2386 part I. The aggregate were sieved in to fractions such as 25-20, 20-16, 1612.5, 12.5-10 & 10-6.3 mm using a mechanical sieve shaker. The AN for each fraction was determined using a three litter capacity cylinder. The weight of empty cylinder (a) was determined. The aggregate of each fraction were filled in the cylinder in three layers tamping each layer 100 times using a tamping rod of 16mm diameter and 600 mm length. The weight of

cylinder with aggregate (b) was determined and the weight of aggregate (w) in the cylinder was found. The cylinder was emptied and filled completely with water. The weight of cylinder filled with water (d) was determined and the weight of water (C) in the cylinder was found. The AN was calculated using the equation.

AN = 67 – 100W/CG

G being the specific gravity of aggregate. The results obtained are presented as Tables 2-4.

Table 2 Aggregate Shape Factors Using Conventional Instruments

Fraction Size mm

Initial weight in g.

Wt. of flaky aggregate

F.I %

Wt. of elongated aggregate.

E.I %

C.I %

AN %

50-40

15000

788

5.2

1807

12.71

17.91

11.7

40-25

10000

749

7.49

4102

44.34

51.83

9.32

25-20

15000

1462

9.74

1540

11.37

21.11

6.32

20-16

10000

1284

12.84

2902

33.29

46.13

10.8

16-12.5

7000

1339

19.12

1791

31.63

50.75

12

12.5-10

4000

971

24.27

1239

40.90

65.17

9.32

10-6.3

5000

1045

20.9

1376

34.79

55.69

9.8

Table 3 Aggregate Shape Factors Using Universal Gauge

Fraction Size Initial wt. mm. in g.

Wt. of flaky aggregate

F.I %

Wt. of elongated aggregate.

E.I %

C.I %

A.N %

45-37.5

15000

661

4.40

2052

14.31

18.71

10.10

37.5-26.5

15000

1588

10.58

5119

38.16

48.74

10.05

26.5-19

10000

1840

18.4

1056

12.94

31.34

8.64

19-13.2

5000

852

17.04

2079

50.12

67.16

9.25

13.2-9.5

3000

770

25.66

717

32.15

57.81

10.17

9.5-4.75

3000

1157

38.56

820

44.49

83.05

8.9

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TECHNICAL PAPERS Table 4 Weighted Average Shape Factors of Test Sample

F.I 11.51 2.5

Using IS sieves E.I C.I

A.N

25.28

9.91

36.79

Using sieves as per gradation by MoRTH for SDBC F.I E.I C.I A.N

Determination of Marshall Test Properties

The Marshall test specimens were prepared first by using the aggregates sieved as per IS set of sieves having 20% and 30% combined index respectively at trial bitumen contents and then using aggregates sieved as per the MoRTH gradation for SDBC at the

13.46

26.83

40.29

9.81

same combined index and trial bitumen contents. The Optimum Bitumen Content (OBC) was determined. The specimens were again prepared at OBC using the aggregates as described and above at the two combined indices and the usual Marshall test properties were determined. The test results are presented in Table 5.

Table 5 Marshall Test Properties at 20% and 30% CI for SDBM Using Conventional Instruments and Universal Gauge

Instrument Conventional Instruments Universal Gauge   Conventional Instruments Universal Gauge

CI % OBC % Stability Kg 20

30

Flow mm

Vv %

Vb %

VMA % VFB %

4.44

1142

3.6

5.1

10.43

11.13

56.17

4.7

1798

4.55

2.93

11.23

9.805

70.94

4.1

1315

2.15

6.18

9.61

11.4

46.3

4.2

1370

3.1

4.42

9.98

10.84

54.24

2.6 Data Analysis The experimental data with regards to aggregate shape factors and Marshall test properties so obtained was

analyzed so as to have comparison when determined as per the two approaches described above. These are presented in Figs. 4 - 11.

Fig. 4 Weighted Average Shape Factors Using Conventional Instruments and UG

Fig. 5 Weighted Average Angularity Number Using Seives as per IS and MoRTH

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TECHNICAL PAPERS

Fig. 6 OBC at 20% & 30% CI for SDBM Using Conventional Instruments and UG

Fig. 10 Marshall Test Results @ 20% & 30% CI for SDBM Using Conventional Instruments and UG

Fig. 7 Marshal Test Result @ 20% & 30% for SDBM Using Conventional Instrument and UG

Fig. 8 Marshall Test Results @ 20% & 30% CI for SDBM Using Conventional Instruments and UG

Fig. 9 Marshall Test Results @ 20% % 30% CI For SDBM Using Conventional Instruments and UG

INDIAN HIGHWAYS, March 2013

Fig. 11 Marshall Test Results @ 20% & 30% CI for SDBM Using Conventional Instruments and UG

3

Conclusions

1.

The values of shape factors such as F.I, E.I and C.I determined by using the two different instruments are different even though the same aggregate sample was used.

2.

These values determined using the universal gauge are more dependable as it considers the actual size of aggregate.

3.

The F.I, E.I determined for the gradation for SDBC indicate slightly higher values using the universal gauge. The C.I is 40.29% using universal gauge as against 36.79% using the conventional instruments.

4.

The Marshall test properties using the same aggregate and gradation based on shape factors determined by conventional and universal gauge instruments are different.

5.

The values of OBC, Stability, Flow, Vb and VFB of SDBC mix based on shape factors 53

TECHNICAL PAPERS 2.

MoRTH- Specification for Road & Bridge Works, 2002.

3.

IS-2386-Part-I, 1964.

4.

IS-2386-Part-III, 1964.

Acknowledgement

5.

Ferasat Hussain, Syed Irshad Geelani, Shahrez Aslam, Naveed Ahmed and Intikhab Ahmed, final year students (Civil Engineering), Ghousia College of Engineering, Ramanagram-562159.

Mohamed Ilyas Anjum, “Effects of Aggregate Shape Factors on Properties of Bituminous Mixes for Road Pavements”, Ph.D. thesis (unpublished), 2005.

6.

Mohanty, K.P, ’ Flakiness of Aggregates for Highway Construction: Its importance and Determination’, Indian Highways, Vol. 23, No.2, Feb 1995.

7.

Ishai, I, and Gelber, H., ‘Effect of Geometric Irregularity of Aggregates on the Properties and Behavior of Bituminous Concrete’, proceedings, Association of Asphalt Paving Technologists, Vol.51,1982.

determined using universal gauge are higher while Vv and VMA are lower compared to those determined using conventional instruments.

REFERENCE 1.

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MOST Specification for Road & Bridge Works, III-Edition, 1998.

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OBITUARY TECHNICAL PAPERS

The Indian Roads Congress express their profound sorrow on the sad demise of Shri Om Prakash resident of D-46, Chander Nagar, Opp. Vivek Vihar of Delhi, Ghaziabad. He was an active member of the Indian Roads Congress. May his soul rest in peace.

The Indian Roads Congress express their profound sorrow on the sad demise of Shri B. S. Malpe resident of 20A1, Bhoop Apartments, Khare Town, Dharmpeth, Nagpur. He was an active member of the Indian Roads Congress. May his soul rest in peace.

The Indian Roads Congress express their profound sorrow on the sad demise of Shri Shyam Bihari Singh resident of Riding Road, Sheikhpura, Po. Veterenary College, Patna. He was an active member of the Indian Roads Congress. May his soul rest in peace.

The Indian Roads Congress express their profound sorrow on the sad demise of Shri M. B. Gharpuray resident of 838, Shivaji Nagar, Pune. He was an active member of the Indian Roads Congress. May his soul rest in peace.

The Indian Roads Congress express their profound sorrow on the sad demise of V. Narayanan resident of A-D 65, Annangar, Chennai. He was an active member of the Indian Roads Congress. May his soul rest in peace.

The Indian Roads Congress express their profound sorrow on the sad demise of Shri M. V. Nagaraja Rao resident of 16th Main, 4th Block, Jayanagar, Bangalore. He was an active member of the Indian Roads Congress. May his soul rest in peace

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