QUALITY CONTROL ASPECTS OF ASPHALT CONCRETE SURFACE REGULARITY S.Gnanasekaran (06/8849) Master of Engineering in Highway & Traffic Engineering Department of Civil Engineering University of Moratuwa Sri Lanka March 2010 QUALITY CONTROL ASPECTS OF ASPHALT CONCRETE SURFACE REGULARITY S.Gnanasekaran (06/8849) Thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering in Highway & Traffic Engineering. Department of Civil Engineering University of Moratuwa Sri Lanka March 2010 i DECLARATION OF THE CANDIDATE “I declare that this is my own work and this thesis does not incorporate without acknowledgement any material previously submitted for a Degree or Diploma in any University or other institute of higher learning and to the best of my knowledge and belief it does not contain any material previously published or written by another person except where the acknowledgement is made in the text” ………… ………………… Signature Date ii DECLARATION OF THE SUPERVISOR “I have supervised and accepted this thesis for the submission of the degree” …………………………. ………………. Signature of the Supervisor Date iii DEDICATION This report is dedicated to my parents. iv ACKNOWLEDGEMENTS I am grateful to my supervisor Dr. W.K.Mampearachchi for all the help and encouragement given throughout the period of research and especially for the advice and direction to prepare my report. His devotion in the subject of Asphalt concrete is also acknowledged. My gratitude is extended to Road Development Authority, Director General, Director Planning and his staff for giving me valuable assistance in completing this study. My sincere thanks are to the University of Moratuwa for the services provided during my research period. I wish to thank the Road Development Authority for sponsoring and granting me leave to follow up this degree course. 22nd March, 2010. v ABSTRACT The purpose of this study is to set an initial road smoothness specification for asphalt concrete overlaid roads in Sri Lanka and to find out the road roughness when the road satisfies the regularity requirement which is given in the Standard Specifications for Construction and Maintenance of Roads and Bridge (SSCM) Published in 1989. Numbers of newly asphalt overlaid roads in various parts of Sri Lanka were surveyed using Vehicle Mounted Bump Integrators and corresponding International Roughness Indices (IRI) were derived. The change of roughness for a short period was also observed. Asphalt overlaid roads with various undulations were surveyed for roughness with Bump Integrator (BI) and the same locations were run with straight edge to measure bump and dip. Smoothness specifications which are currently in use in other countries are taken into consideration. The outcome of roads of those countries as a result of setting a smoothness target is also discussed. This study revealed that it is practical to set an initial roughness value in terms of IRI when the roughness is measured with BI and the roughness does not change drastically in a short period. Also, it is revealed that the maximum tolerance of surface regularity given the SSCM published in 1989 results a higher IRI value. vi TABLE OF CONTENTS Declaration of the candidate i Declaration of the supervisor ii Dedication iii Acknowledgement iv Abstract v Table of content vi List of Figures viii List of Tables ix Chapter 1: Introduction 1 1.1 Background 1 1.2 Problem statement 2 1.3 Objectives 3 1.4 Research approach, scope and limitation 3 Chapter 2: Literature review 4 2.1 Road roughness 4 2.2 Roughness measuring systems 5 2.2.1 Profiling devices 5 2.2.2 Response type devices 10 2.3 Pavement roughness indices 12 2.3.1 International Roughness Index (IRI) 12 2.3.2 Present Serviceability Rating (PSR), Present Serviceability Index PSI and Mean Panel Rating (MPR) 14 2.3.4 Ride Number 16 2.3.5 Slope Variance 17 2.3.6 Other roughness indices 17 2.4 Roughness measurement- Current practice in Sri Lanka 18 2.4.1 Roughness measuring devices 18 2.4.2 The use of roughness measurements 18 2.5 Pavement smooth specifications 22 vii Chapter 3 Methodology of study 27 3.1 Calibration of Vehicle Mounted Bump Integrator using Merlin 27 3.2 Measuring roughness 28 3.2.1 Using Bump Integrator 28 3.2.2 Using Straightedge measurements 30 Chapter 4: Observation and Results 31 4.1 Variation of roughness with time 31 4.2 IRI and Straightedge 43 Chapter 5: Analysis and discussion of results 45 5.1 Introduction 45 5.2 Initial road roughness and its variation with time for a Short period 45 5.2.1 General observations and preliminary data analysis 45 5.2.3 Data analysis 46 5.3 IRI and Straightedge 48 Chapter 6: Conclusions and recommendations 50 6.1 Conclusions 50 6.2 Recommendations 50 Reference List: 52 Appendix A: Straightedge readings 53 Appendix B: MERLIN chart 106 Appendix C: Roughness measurements- Southern Expressway 107 viii LIST OF FIGURES Figure 2.1 Straightedge 6 Figure 2.2 Dipstick 7 Figure 2.3 MERLIN Machine 8 Figure 2.4 Inertial Profiler 10 Figure 2.5 Vehicle Mounted Bump Integrator 11 Figure 2.6 Quarter Car Model 13 Figure 2.7 Sensitivity of IRI to Wave Numbers 13 Figure 2.8 IRI Roughness scale 14 Figure 2.9 Present Serviceability Rating scale 15 Figure 2.10 Sensitivity of RN to Wave numbers 16 Figure 2.11 Correlation between PI (used to define RN) and IRI 17 Figure 2.12 Road length distributions by roughness in 2008 19 Figure 2.13 Roughness distributions by province in 2007 20 Figure 2.14 Roughness distributions by province in 2008 21 Figure 4.1 Roughness on CRWB road 32 Figure 4.2 Average IRI variation with time on CRWB road 33 Figure 4.3 Roughness on CGHW road 34 Figure 4.4 Average IRI variation with time on CGHW road 35 Figure 4.5 Roughness on CK road 36 Figure 4.6 Average IRI variation with time on CK road 37 Figure 4.7 Roughness on PNR road 38 Figure 4.8 Average IRI variation with time on PNR road 39 Figure 4.9 Roughness on MHT road 41 Figure 4.10 Average IRI variation with time on MHT road 41 Figure 4.11 IRI vs. Straightedge 44 Figure 5.1 IRI vs. Straightedge 49 ix LIST OF TABLES 2.1 Road Length Distribution by Roughness 18 2.2 Roughness Distribution by Province in 2007 19 2.3 Roughness Distribution by Province in 2008 20 2.4 Summary of Acceptance Requirements and Pay Adjustments in Canada 23 2.5 Comparison of Smoothness Specifications from Selected European Countries 25 2.5 Tolerance of surface regularity in Sri Lanka -SSCM, 1989 26 2.6 Tolerance of surface regularity in Sri Lanka -ICTAD Specification 26 3.1 Selected roads for calibrating Bump Integrator 27 3.2 Selected roads for measuring roughness 29 4.1 Roughness measurement on CRWB road 31 4.2 Summary on Roughness measurement on CRWB road 33 4.3 Roughness measurement on CGHW road 34 4.4 Summary on Roughness measurement on CGHW road 35 4.5 Roughness measurement on CK road 36 4.6 Summary on Roughness measurement on CK road 37 4.7 Roughness measurement on PNR road 38 4.8 Summary on Roughness measurement on PNR road 39 4.9 Roughness measurement on MHT road 40 4.10 Summary on Roughness measurement on MHT road 41 4.11 Roughness measurement on KKP road 42 4.12 Summary on Roughness measurement on KKP road 43 4.13 IRI measurement vs. Straightedge 44 5.1 Summary of IRI values 47 5.1 Summary of 5%, 50% and 95% Values 47