Department of Civil Engineering, Indian Institute of Science Bangalore
Condition Assessment of Pavements and Subgrade
Condition Assessment of RoadsEvaluation of flexible and rigid pavement is important for providing data to pavement management systems (PMS). Pavement parameters of quality, thickness and density are important parameters for pavement evaluation and condition assessment. Condition assessment of roads is a well known routine problem in transportation infrastructures maintenance. Many conventional methods practiced are time consuming and random testing. In this study condition of pavement and subsurface layers are evaluated using conventional and modern geophysical methods and compared the results. Ground Penetration Radar (GPR) is an electromagnetic method and widely used to study many subsurface problems. In this study an attempt will be made to assess the existing pavement and substructures layers using GPR . Thirty one GPR surveys are carried out in different road conditions (good quality to bad quality) in and around Indian Institute of Science and the velocity and thickness of the pavement layers are estimated. In the same locations in-situ samples are extracted using core cutting machine. The in-situ samples are used to measure thickness, density, bitumen content and gradation of aggregates by carrying out laboratory tests. The study shows that thickness of the pavement layers can be obtained from GPR with 91% accuracy. Visual classification and stiffness calculated are matching with non destructive tests results. GPR is an effective method to estimate thickness and heterogeneity in the bitumen concrete with short time.