Effect of freeze–thaw cycles on the resilient moduli and unconfined compressive strength of rubberized recycled concrete aggregate as pavement base/subbase

One of the most practical ways to reduce the demand for natural aggregates in the construction industry and dispose of the construction and demolition (C&D) wastes in landfills is using recycled concrete aggregate (RCA) for pavement base and subbase applications. Previous researches have mainly concentrated on the engineering behavior of C&D aggregates under ambient temperature. Little research has been directed toward the possible impact of temperature on the performance of rubberized recycled concrete aggregate for pavement base/subbase applications. In this study, for the first time, the effects of freeze–thaw process on the engineering properties of RCA containing crumb rubber for pavement base and subbase applications were evaluated. The results show that the resilient modulus of the RCA/rubber blends subjected to freeze–thaw cycles was higher than that of the control samples (prepared and tested at constant room temperature of 25 °C). The unconfined compressive strength (UCS) of F-T samples (subjected to one-day freezing, followed by one-day thawing) was slightly lower than that of the control samples. It was found that the UCS value of T-F samples (subjected to one-day thawing, followed by one-day freezing) was remarkably higher than that of the control samples. Based on the preliminary experimental results, the blends of RCA and crumb rubber, as a low carbon concept and an economically viable option, can be used for pavement base/subbase subjected to freeze–thaw cycles.