Evaluation of Effect of Rolling Direction on Unbound Material Modulus Using Portable Seismic Pavement Analyzer (PSPA)

摘要

In order to provide adequate support to the surface layer of airfield pavement, the base, subbase and subgrade must be compacted to high density. Generally, the pavement materials are compacted by roller in the longitudinal direction. It may cause property variance between longitudinal and transverse directions. Portable Seismic Pavement Analyzer for Soils (D-PSPA) was used to evaluate the effect of rolling direction on unbound material modulus. A series of D-PSPA tests were conducted on subgrade, subbase and base materials at the National Airport Pavement Test Facility (NAPTF) in both longitudinal and transverse directions. Single factor analysis of variance (ANOVA) was performed on test results to investigate whether there is a significant difference between two directions. The preliminary data analysis indicates that the seismic modulus measured in longitudinal direction is higher than transverse direction for subbase. Higher seismic modulus was obtained in transverse direction for base. Subgrade, on the other hand, appears to be not affected by the rolling direction.