Asphalt concrete improved by concentrated rubber latex and prevulcanized rubber latex – Performance and cost analysis

Natural rubber (NR) is categorized as a natural elastomer having capacity to modify the properties of asphalt cement. Pre-vulcanized NR latex (PVL) and concentrated latex (CL) were selected as modifiers for asphalt binder penetration grade 60/70 in term of dry rubber content to asphalt binder (r/b) ratios by the total weight of the asphalt cement. The CL and PVL asphalt concrete (CL-AC and PVL-AC) samples were fabricated utilizing the Marshall method. Overall engineering properties of asphalt binder were improved by CL and PVL inclusion. The improved properties of asphalt binder had a direct impact on the enhancement of pavement performance, including Marshall stability, indirect tensile strength (ITS), indirect tensile resilient modulus (IT Mr), indirect tensile fatigue life (ITFL), and rutting resistance. The optimum performance (highest Marshall stability, ITS, IT M r , ITFL, and the lowest rut depth) achieved at r/b = 3 % for both CL-AC and PVL-AC. For the same r/b ratio, the PVL-AC had better properties than CL-AC. For PVL-AC was found to have lower initial strain and higher ITFL than CL-AC under a specific cyclic load. Based on the developed distress model and mechanistic design approach, the calculated pavement thickness of CL-AC and PVL-AC was found to be insignificant under the same traffic volume, whereas the construction cost of PVL-AC was much more expensive. The CL-AC demonstrated superior cost-effectiveness compared to PVL-AC and conventional AC pavements for the same traffic volume.