Evaluation of the Resilient Modulus of Hot-Mix Asphalt Made with Recycled Concrete Aggregates from Construction and Demolition Waste

Abstract

This paper reports the influence of the percentage of recycled aggregate (RCA) from construction and demolition waste (C&DW) together with the percentage of binder (L), curing time (t) and temperature (T) of the samples on the stiffness of a hot asphalt mixture. The study was carried out using the response surface methodology (RSM). The resilient modulus was chosen to estimate the stiffness of the mixture. The percentages of RCA studied were 0% (control), 5%, 10%, 20% and 30%, whilst 3.5%, 4% and 4.5% were those chosen for the binder content. Before compacting the samples, they were left into the oven to cure. Curing time, or pretreatment time, were set at 0 (control), 2 and 4 h. The samples were subjected to temperatures of 0, 10 and 20 °C. The natural aggregate is of the hornfels type. All the specimens studied showed high stiffness at low temperatures. According to this research, temperature proved to be the most influential factor on the decrease in the resilient modulus and, conversely, the percentage of recycled aggregate is not a significant factor in the range of values studied.