Workability, compactibility and engineering properties of rubber-modified asphalt mixtures prepared via wet process

Abstract

The purpose of this study is to compare the performance of rubber-modified asphalt mixtures prepared with incorporation of latex and crumb rubber. The service characteristics of the rubber-modified asphalt mixtures were evaluated using workability index and compaction energy index to determine the ease of placing, handling, and compacting of the asphalt mixture. The engineering properties of the asphalt mixtures were also evaluated in terms of indirect tensile strength (ITS), resilient modulus, permanent deformation, moisture susceptibility, and the Leutner shear test. Crumb rubber and latex were separately used as modifiers in this study. The percentage of crumb rubber and latex used were 5% and 10%, while organo silane additive was added at a rate of 0.1%, all by the weight of asphalt binder. Through the evaluation, the modified asphalt mixture required comparable energy for compaction through the assessment of compaction energy index (CEI) as compared to the control asphalt mixture. Based on the results of performance test, it can be concluded that the crumb rubber-modified asphalt mixture showed a better performance than the latex-modified asphalt mixture in terms of fracture resistance, permanent deformation, resilient modulus, shear resistance, and moisture resistance. Overall, the rubberised asphalt mixture has better engineering performance properties that can prolong the lifespan of the flexible pavement compared to the conventional asphalt mixture.