Cement Stabilization of Aggregate Base Material Blended with Reclaimed Asphalt Pavement

Abstract

The effects of reclaimed asphalt pavement (RAP) content and cement content on the strength and durability of recycled aggregate base materials typical of the I-84 pavement reconstruction project performed in Weber Canyon near Morgan, Utah, were investigated. The laboratory work was based on a full-factorial experimental design, including five RAP contents, five cement contents, and three replicate specimens of each possible treatment. Measurements of unconfined compressive strength (UCS) and final dielectric value in the tube suction test (TST) were used to assess material strength and durability, respectively. These data, together with dry density measurements, were evaluated through an analysis of variance (ANOVA). The results of the ANOVA performed on the UCS data indicate that UCS decreases from 425 to 208 psi as RAP content increases from 0% to 100% and increases from 63 to 564 psi as cement content increases from 0.0% to 2.0%. Similarly, the final dielectric value decreases from 14.9 to 6.1 as RAP content increases from 0% to 100% and decreases from 14.0 to 5.8 as cement content increases from 0.0% to 2.0%. Increasing RAP contents generally correspond to decreasing dry densities. With design criteria requiring 7-day UCS values between 300 and 400 psi and final dielectric values less than 10 in the TST, the results of this research suggest the use of RAP contents in the range of 50% to 75% and a cement content of 1.0% for this material.