EFFECT OF SILICA FUME ASH ON BOND STRENGTH and compressive strength OF CONCRETE

A Dissertation work submitted to theFaculty of Engineering of Kakatiya University, WarangalIn partial fulfillment of the requirements for the award of the degree of

MASTER OF TECHNOLOGYINSTRUCTURAL & CONSTRUCTION ENGINEERINGBy

Under the Guidance of

Estd: 1980DEPARTMENT OF CIVIL ENGINEERINGKAKATIYA INSTITUTE OF TECHNOLOGY & SCIENCE(Affiliated to Kakatiya University)WARANGAL 5060152014-2015

KAKATIYA INSTITUTE OF TECHNOLOGY & SCIENCEDEPARTMENT OF CIVIL ENGINEERING(Affiliated to Kakatiya University)WARANGAL 5060152014-2015

CERTIFICATE

This is to certify that this project work entitled EFFECT OF SILICA FUME ASH ON BOND STRENGTH and compressive strength OF CONCRETE. is the bonafied work carried out by M.SRAVANTHI bearing Roll No.13016T6018 in partial fulfillment of the requirements for the award of degree of the M.Tech Structural and Construction Engineering from Kakatiya University, Warangal during the academic year 2014-2015.

Dissertation Guide Head of the Department

DECLARATION

I declare that the work presented in this project report is original and carried out in the Department of Civil Engineering, Kakatiya Institute of Technology & Science, Telangana State and had not been submitted anywhere for any Post Graduate degree in part or full to the best of my knowledge.

M.SRAVANTHI (13016T6018)

ACKNOWLEDGMENTI highly obliged to express my deep felt thanks for the initiation of the project byDr. M. Veera Reddy Professor of Department of Civil Engineering, Kakatiya Institute of Technology & Sciences Kakatiya University. It is with great pleasure that I express my gratitude for their guidance & advice with which this study has been carried out. I thank for their valuable suggestions and worthy counsel.I sincerely thank the Faculty of Civil Engineering Department and Sri. M. SRIKANTH, Associate Professor and Coordinator of M.Tech (Structural and Construction Engineering).I like to express sincere thanks to Prof. S. G. Narayana Reddy, Head of the Department of Civil Engineering, for continuous help and support to me.I wish to express my sincere thanks to Dr. K. ASHOKA REDDY, Principal, Kakatiya Institute of Technology and Science, Warangal, for providing the necessary infrastructure and good academic environment in an endeavor to complete the project and special thanks for providing Department Library of Civil and Digital Library to access journals.It is my pleasure to acknowledge Sri. V. Krishna Murthy Mechanic, Concrete Laboratory & Sri. S. Vidya Sagar Mechanic, Material Testing Laboratory who helped in the completion of the work.I offer my earnest gratitude to all the people who helped me directly or indirectly in the completion of this Dissertation.

M.SRAVANTHI

CONTENTS

CHAPTER 1: INTRODUCTION 1.1. Silica Fume-3 1.2. Bond Strength-6 1.3. Scope of the project -9 1.4. Objective of the project -9CHAPTER 2: LITERATURE REVIEW -10CHAPTER 3: EXPERIMENTAL PROGRAMME 3.1. General-15 3.2. Materials-15 3.3. Mix Design Proportions-21 3.4. Moulds & Equipment-25 3.5. Testing-26Test for Compressive Strength Test (cubes)Test for Bond Strength test (cylinders & cubes) 3.6. Development Length-31CHAPTER 4: RESULTS AND DISCUSSIONS 4.1. General -36 4.2. Mix Proportioning of Silica Fume and concrete-36 4.3. Strength characteristics of concrete-37

CHAPTER 5: CONCLUSIONS - 79CHAPTER 6: REFERENCES - 80

LIST OF TABLES

Sl no. Name of the table

1. Properties of cement2. Sieve analysis of fine aggregate3. Sieve analysis of coarse aggregate4. Physical Properties of Silica Fume5. Reinforcing Bars Details6. Experimental Programme7. Mix proportion of concrete for every 5% replacement of Silica Fume8. Compressive strength & Bond Strength of concrete in N/mm29. Comparison of Bond strength Pullout to push out10. Comparison of bond Strength Twist bar to plain bar11. Comparison of bond Strength by Orangun et al12. Comparison of bond Strength by Australian standards 360013. Comparison of bond Strength by Esfahani and Rangun14. Comparision of ratios of Orangun et al, Australian standards 3600 & Esfahani and Rangun15. Push out test on cubes 16. Pull out test on cubes 17. Push out test on cylinders 18. Pull out test on cylinders

LIST OF FIGURES Sl no. Name of the figure1. General details of free bar in the specimen2. Compressive Testing Machine3. Universal testing machine4. Casting of specimens5. Test specimens after 28 days curing6. Specimen while testing in push out test and pull out test (Universal testing machines7. Failure pattern of push out test of cube and cylinder specimens with 16mm diameter, HYSD bars8. Push out test on cubes A. 0% Silica fume using Plain bars fig A1,A2B. 0% Silica fume using Twist bars used fig B1,B2C. 5% Silica fume using Twist bars used fig C1,C2D. 10% Silica fume using Twist bars fig D1,D2E. 15% Silica fume using Twist bars fig E1,E2F. 20% Silica fume using Twist bars fig F1,F29. Pull out test on cubes A. 0% Silica fume using Plain bars fig A3,A4B. 0% Silica fume using Twist bars fig B3,B4C. 5% Silica fume using Twist bars fig C3,C4D. 10% Silica fume using Twist bars fig D3,D4E. 15% Silica fume using Twist bars fig E3,E4F. 20% Silica fume using Twist bars fig F3,F410. Push out test on cylinders A. 0% Silica fume using Plain bars fig K1,K2B. 0% Silica fume using Twist bars fig L1,L2C. 5% Silica fume using Twist bars fig M1,M2D. 10% Silica fume using Twist bars fig N1,N2E. 15% Silica fume using Twist bars fig O1,O2F. 20% Silica fume using Twist bars fig P1,P211. Pullout test on cylindersA. 0% Silica fume using Plain bars fig K3,K4B. 0% Silica fume using Twist bars fig L3,L4C. 5% Silica fume using Twist bars fig M3,M4D. 10% Silica fume using Twist bars fig N3,N4E. 15% Silica fume using Twist bars fig O3,O4F. 20% Silica fume using Twist bars fig P3,P4 12. Push Out test on Cube for various percentages of Silica fume 13. Pull Out test on Cube for various percentages of Silica fume. 14. Push Out test on Cylinder for various percentages of Silica fume. 15. Pull Out test on Cylinder used for various percentages of Silica fume.

ABSTRACTBond Strength can be considered from two different angles one is the bond strength between paste and steel reinforcement and the other is the bond strength between paste and aggregate. Bond Strength between paste and steel reinforcement is of considerable importance. A perfect bond, existing between concrete and steel reinforcement is one of the fundamental assumption of reinforced concrete Bond Strength arises primarily from the friction and adhesion between concrete and steel the roughness of steel surface is also one of the factors affecting bond strength. The bond strength of concrete is approximately proportional to the compressive strength up to about 20 MPa. For higher strength concrete, increase in bond strength becomes progressively smaller.Mineral additions which are also known as mineral admixtures have been used in Portland cement for many years. There are two types of additions which are commonly mixed into the Portland clinker or blended directly with cement these days. They are crystalline, also known as hydraulically inactive additions and pozzolanic, which are hydraulically active additions. Silica fume is very reactive pozzolan, while it is used in concrete because of its fine particles, large surface area and high SiO2 content. Silica fume is much fined separated silica obtained as a by-product in industry. The main parameter investigated in this study is M25 grade concrete with partial replacement of cement by silica fume by 0%, 5%, 10%, 15% and by 20% and using 16mm diameter plain and twist bars to determine the bond strength of concrete. This project presents a detailed experimental study on Compressive strength, Bond strength at age of 28 days. For different embedded lengths of steel bars were considered in present tests namely 15cm and 30cm for push out test on cube and cylinder, 15cm and 30cm for pullout test on cube and cylinder.The Experimental values indicated that, the bond stress Increases 45.80% to 75.80%, when deformed bars are used in comparison of plain bars.