A GPR Based Non-destructive Approach to Monitor the Engineering Properties of Compacted Base Layer

Construction variability and isolated defects in base layer can be limiting factors in pavement’s service life. To control construction quality and implement an efficient quality management system, this study develops a quick, accurate, and simple non-destructive method using ground penetrating radar (GPR) to determine reliable values of in-place compacted base material properties, such as suction (h_m), water content (θ), dry density (γ_d), and resilient modulus (M_R). To overcome the challenges associated with timely laboratory testing on core samples, a set of mechanistic empirical characteristics curve models were utilized and corresponding fitting parameter prediction models were proposed based simple laboratory tests like the Methylene Blue Test (MBT), Percent Size Distribution Analyzer Test, Percometer Test, and Aggregate Imaging Measurement System (AIMS) Test. The laboratory characterization results were integrated with GPR scan data and processed using two GPR signal analysis software programs, PaveCheck and LayerMAPP, to generate a strip map of the in-situ base properties along the pavement section. Finally, to validate the results from the GPR-based approach, the predicted profile of base material properties from filed test sections was compared with results from other non-destructive methods such as the Nuclear Density Gauge and Falling Weight Deflectomter.