Investigation of the mechanical properties and carbonation of construction and demolition materials together with rubber

One of the ways to improve the strength properties of construction and demolition (C&D) wastes is to adopt the accelerated carbonation technique. The main objective of this study was to evaluate the effects of the eco-friendly carbonation approach on the mechanical properties of C&D aggregates together with crumb rubber. Crumb rubber with particle sizes ranging from 400 to 600 μm was added to the 20 mm recycled concrete aggregate (RCA) and crushed rock (CR) at 0.5, 1, and 2% by weight percentage of the aggregates. Then, the unconfined compression strength (UCS) and resilient modulus (Mr) tests were conducted on the carbonated RCA and CR samples together with crumb rubber, and the results were compared with those of the uncarbonated specimens. The results showed that the carbonation process led to a significant increase in the UCS values. However, carbonation resulted in a decrease in the deformability of the specimens compared with the uncarbonated specimens. Moreover, carbonation resulted in a significant increase in the Mr values compared with those of the uncarbonated values. Also, the carbonation process had a more substantial effect on the Mr values of the CR than of the RCA.