Evaluation of Warm Mix Crumb Rubber Modified Asphalt Mixture (WCRMA) on resisting permanent deformation

Abstract

Crumb rubber (CR) is generated from the recycling of used or discarded car tires and has long been utilized in the paving industry. Crumb rubber can be used in asphalt mixes in two ways: dry process and wet process. However, compared to standard combinations, crumb rubber modified asphalt (CRMA) requires much higher mixing and compaction temperatures. As a potential substitute, using warm mix asphalt (WMA) technology significantly lower hot-mix asphalt (HMA) production and placement temperatures through viscosity reduction. In accordance, the objectives of the study are to produce warm mix crumb rubberized asphalt mixtures (WCRMA) using a dry process and to evaluate WCRMA’s performance in terms of rutting resistance. WCRMA is produced by adding 1, 3, and 5% Sasobit® of the total weight of the binder. The rutting performance of WCRMA was evaluated by Dynamic Creep test. The result showed that the asphalt mixes with the largest percentages of Sasobit® (5%) showed the lowest lowest accumulated strain and permanent deformation. The modified asphalt mixture performed better and had greater rutting resistance due to the replacement of fine aggregate with crumb rubber and the addition of Sasobit® compared to control sample.