NDE methods for quality assurance of new pavement thickness

Abstract

Accurate measurement of pavement thickness is an essential aspect of the quality assurance of new pavement construction. Current coring methods are time consuming and provide a very limited representation of the overall pavement structure. The objective of the work described in this paper has been to demonstrate the use of non-destructive evaluation (NDE) methods for rapidly determining the average pavement thickness on a newly constructed section to within 2.5 mm of the true value, without extensive reliance on cores. The effort has considered ground penetrating radar (GPR) and impact echo methods applied to both asphalt and concrete pavement, and has included laboratory and field-testing, with field correlations based on 172 cores. The results show that the 2.5 mm accuracy objective can be met for asphalt pavement, but that accuracy on concrete is limited to 4 mm. The paper describes the techniques that were evaluated, the testing that was conducted, and the results of correlation with core data.

Keywords:

• Pavement construction
• Ground penetrating radar (GPR)
• Impact-echo
• Pavement thickness
• Quality assurance
• Non-destructive evaluation

Acknowledgements

The authors would like to acknowledge Doria Kutrubes of Radar Solutions International for assistance with GPR data collection; Laura McGrath of Infrasense for her assistance with data analysis; Dr Paul Foxworthy of Applied Research Associates for his assistance in arranging access to sites and obtaining core data; Dr Alex Gibson of Olson Engineering for his assistance in collection and analysis of IE data; Professor Rajib Mallick of Worcester Polytechnic Institute for assistance with the setup of the asphalt test slab; and Alfredo Rodriguez of California DOT for his assistance in conducting the field tests. The authors would also like to acknowledge Geophysical Survey Systems, Inc. and Worcester Polytechnic Institute for providing test facilities; Olson Instruments, Inc. for providing test equipment, and California DOT for their support of this work.