Characterization of HMA Mixtures ontaining High Reclaimed Asphalt Pavement Content With Crumb Rubber Additives

摘要

This paper presents the findings of laboratory characterization of HMA mixtures containing high reclaimed asphalt pavement (RAP) content with crumb rubber (CR) additives. Six mixtures were examined in this study. Three were conventional mixtures containing an unmodified asphalt cement binder and styrenebutadiene-styrene polymer modified asphalt cement, Performance Grade (PG) 64-22, PG 70-22, and PG 76-22 respectively. The fourth mixture contains no RAP, 30 mesh CR additives blended (wet process) with a PG 64-22 binder. The fifth mixture contains 15 percent RAP and PG 76-22 asphalt cement binder The final mixture contains 40 percent RAP, 30 mesh CR additives blended (dry process) with a PG 64-22 asphalt cement binder. Laboratory mixture characterization includes the asphalt mixture performance tests (dynamic modulus, E*, and flow number, FN), semi-circular bend test, dissipated creep strain energy test, and the modified Lottman test. Mixtures containing high RAP content and CR additives exhibited similar performance as conventional mixture with PG 76-22 binder.