Effect of temperature on resilient modulus and shear strength of unbound granular materials containing fine RAP

The objective of this paper is to investigate the effect of temperature on mechanical properties of unbound granular materials (UGMs) blended with reclaimed asphalt pavement (RAP) and virgin aggregates as the base course of pavement. To this end, a series of laboratory tests including the repeated load triaxial test (RLT) and the quick shear test was performed on gap graded, continuous graded and coarse graded UGMs containing RAP (RAP-UGMs) as well as UGMs of neat virgin aggregates (VA-UGMs) at varying temperatures, 40 degrees C, 22 degrees C, 5 degrees C, and 10 degrees C. In addition, one set of specimens subjected to a freeze-thaw (F-T) cycle was tested to evaluate the susceptibility to that. It is found that temperature has significant effects on Mr and shear strength of both RAP-UGMs and VA-UGMs. Compared to VA-UGMs, RAP-UGMs exhibit fairly comparable Mr at non-freezing temperatures. However, the addition of RAP apparently lowers the shear strength of UGMs. For both RAP-UGMs and VA-UGMs, Mr has very significant growth at 10 degrees C compared to non-freezing temperatures while the growth for RAP-UGMs is apparently lower than that for VA-UGMs. Moreover, RAP-UGMs are less susceptible to the F-T cycle than VA-UGMs. And the addition of RAP improves the F-T resistance of UGMs. (C) 2016 Elsevier Ltd. All rights reserved.