Volume 26, Issue 4 (July 1998)
Variation of Resilient Modulus of Aggregate Base and Its Influence on Pavement Performance
Resilient modulus (MR), which properly characterizes the load-deformation response of pavement materials under traffic loading, is evaluated. The MR variations due to three different gradations and three different moisture contents were investigated for Richard Spur (RS) aggregate, 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 Transportation (ODOT) for Type A aggregate. The three moisture contents selected are optimum moisture content (OMC), 2% below and 2% above the OMC. Six duplicate MR tests under identical conditions were conducted for each case by using the AASHTO designation T 294-94. The variabilities of MR values due to the three different gradations and three different moisture contents were found to be within 10 to 50% and 10 to 20%, respectively. Furthermore, the material model coefficients K1 and K2 were calculated, and a multiple linear regression model for predicting the MR values of the aggregate was established in this study. Finally, the effect of MR variation on pavement performance was demonstrated by using one pavement design example.