Field and Laboratory Characterization of Cement Treated Permeable Base for Flexible Airport Pavement at the FAA's National Airport Pavement Test Facility

The performance of cement treated permeable base (CTPB) material under full-scale aircraft traffic is investigated on two dedicated pavement sections during construction cycle 9 (CC9) at the Federal Aviation Administration's (FAA) National Airport Pavement Test Facility (NAPTF). Laboratory and field characterization of the CTPB material was performed during the construction stage. In addition to testing for compressive and flexural strength, measuring resilient modulus on 28-day cured CTPB cylindrical specimens was experimented as part of the laboratory characterization. Although producing specimens of flat and smooth end surfaces was one of the major challenges in measuring reliable vertical deformations, stress-dependency of CTPB material was captured in the resilient modulus test results. The light weight deflectometer (LWD) was identified as a feasible field alternative for the characterization test on the finished CTPB surface. The CTPB modulus measured in the laboratory was approximately 1.8-2.6 times the field modulus derived from LWD testing. This paper discusses laboratory and field characterization results and provides an overall evaluation of CTPB material properties and anticipated performance under full-scale traffic. The implications of test results for future CTPB material FAA specifications are also addressed.