VARIATION OF RESILIENT MODULUS OF AGGREGATE BASE AND ITS INFLUENCE ONPAVEMENT PERFORMANCE

Resilient modulus (M-R), which properly characterizes the load-deforma tion response of pavement materials under traffic loading, is evaluate d. The MR variations due to three different gradations and three diffe rent moisture contents were investigated for Richard Spur (RS) aggrega te, which is commonly used in Oklahoma as the base material of roadway pavements. The three gradations selected are finer limit, median, and coarser limit, as specified by the Oklahoma Department of Transportat ion (ODOT) for Type A aggregate. The three moisture contents selected are optimum moisture content (OMC), 2% below and 2% above the OMC. Six duplicate M-R tests under identical conditions were conducted for eac h case by using the AASHTO designation T 294-94. The variabilities of MR values due to the three different gradations and three different mo isture contents were found to be within 10 to 50% and 10 to 20%, respe ctively. Furthermore, the material model coefficients K-1 and K-2 were calculated, and a multiple linear regression model for predicting the M-R values of the aggregate was established in this study. Finally, t he effect of M-R variation on pavement performance was demonstrated by using one pavement design example.