Airfield pavement evaluations were performed at four military installations by the U.S. Army Engineer Research and Development Center (ERDC). A number of rigid airfield pavement features at each installation underwent structural testing using the heavy weight deflectometer (HWD) and the portable seismic pavement analyzer (PSPA). The HWD data were used to backcalculate layer moduli for each pavement structure based on the composition of the underlying layers, and layer thickness from historical construction records. The PSPA data were used to calculate the in situ properties for the pavement layers in terms of Young's modulus. PSPA estimated moduli were used to calculate in situ flexural strengths of the rigid pavements based on a predetermined relationship between the PSPA-measured modulus and flexural strength. Structural analyses were performed using the flexural strengths obtained from as-built construction records or historical splitting tensile test results and the flexural strengths estimated from PSPA moduli. Results indicated that the structural capacity of rigid pavements was slightly more conservative when the PSPA moduli were used to calculate the flexural strength than when historical construction data were used. As a result, structural capacity decreased and overlay requirements increased when the PSPA data were used in lieu of the historical data. The PSPA provides a useful tool for analyses of structural capacity, particularly when historical data is not available. The PSPA reduces the logistical requirements associated with obtaining core samples and reduces the time required to perform the pavement evaluation while providing an adequate assessment of flexural strength.
Abstract