Performance of Coarse Graded Unbound Granular Materials Containing RAP

In order to solve the problem of the application of reclaimed asphalt pavement (RAP) in unbound granular materials, an investigation into the effect of RAP on the performance of coarse graded unbound granular materials was conducted. A series of laboratory tests used UTM-100 including the repeated load triaxial test, the quick shear test and the permanent deformation test were performed on coarse graded UGMs containing RAP as well as UGMs of neat virgin aggregates at room temperature(22 ℃).The effect of RAP on the performance of unbound granular materials was analyzed in accordance with the experimental results.The test results show that after adding RAP, the dynamic resilient modulus of coarse graded unbound granular materials increase obviously, and the average growing rate is 9.3%. The growing rate is affected by confining pressure and the ratio of bias to confining pressure. And the ratio of bias to confining pressure has more significant influence. The shear strength decrease and the decreasing rapid is slower in stress softening stage. When shear failure occurs, coarse graded unbound granular materials have similar dilatancy effect. Axial permanent deformation increases distinctly, which shows material's resistance to permanent deformation declined.