High and intermediate temperature performance evaluation of crumb rubber modified binders with RAP

Abstract

Abstract The present study was undertaken to evaluate high and intermediate temperature performance of a crumb rubber modified binder (CRMB60) blended with different percentages (i.e., 0%, 15%, 25% and 40%) of binder extracted from reclaimed asphalt pavement (RAP). The Brookfield viscosity, Superpave high performance grade (PG), and complex modulus were measured for CRMB60 blended with RAP. The rutting and fatigue resistances of CRMB60 with and without RAP were evaluated using multiple stress creep and recovery (MSCR) and linear amplitude sweep (LAS) tests, respectively. The results showed that addition of RAP improves temperature susceptibility of CRMB60. The Superpave high PG of CRMB60 binder bumped by one PG interval (i.e., PG88–PG94) with addition of 15% and 25%RAP. However, further increase in RAP (40%RAP) did not alter PG, which is contrary to what have been reported in literature. The MSCR test showed that non-recoverable creep compliance ( J nr ) of CRMB60 decreased with an addition of RAP up to 25%, indicating the improved rutting resistance of CRMB60. However, J nr of CRMB60 increased with addition of higher percentage of RAP (i.e., 40%), showing poor rutting resistance compared to control CRMB60. The LAS test showed that fatigue damage resistance of CRMB60 with 15% and 25% RAP was less compared to control CRMB60. Overall the present work showed the addition of RAP increased rutting resistance, however, deteriorated fatigue performance of CRMB60. The higher percentage of RAP showed a different trend than expected, which might be due to reduced concentration of rubber particles or depolymerization of rubber particles after addition of high content of RAP.