Experimental Evaluation of Mechanical Characteristics of Roller-Compacted Concrete Containing Crumb Rubber, RAP and Slag.

This study aims to employ the maximum allowed amount of waste materials in the roller- compacted concrete (RCC) mixture using three types of waste materials, namely slag, reclaimed asphalt pavement (RAP) and crumb rubber. A mix design, including recycled materials with the maximum amount allowed to be used in the mixture, is presented by combining alternative materials and covering defects of each alternative material with another alternative material. To make samples containing waste materials, crumb rubber replaces the material passed through the 3/8-inch sieve and remains on sieve no. 50, RAP as the main material replaces coarse aggregates and slag replaces the remaining part of coarse aggregates after RAP replacement. Compressive strength, flexural strength and indirect tensile strength tests are used to evaluate RCC mixture performance. The results indicate increasing RAP decreases indirect tensile strength and increases flexural strength of samples. Moreover, increasing RAP by 50% increases compressive strength and, then, decreases compressive strength if it exceeds 50%. Adding slag to the mixture increases compressive and indirect tensile strength. Also, increasing slag by 50% increases flexural strength of samples and, then, decreases this strength if it exceeds this value. Increasing crumb rubber by 50% decreases compressive strength by 65% and indirect tensile strength of samples by 59.7% compared to the control sample. Increasing crumb rubber by 15% increases flexural strength and, then, decreases this strength if it exceeds this value. Finally, a RCC sample with 70% RAP, 25% slag and 10% crumb rubber is proposed as the final mix design. [ABSTRACT FROM AUTHOR]