Influence of Natural Coarse Aggregate Type on the Transport Properties of Recycled Concrete

The use of recycled concrete represents an environmentally friendly solution for minimizing the impact of construction and demolition wastes. In many countries, the incorporation of recycled coarse aggregate (RCA) is a common practice because the maximum contents of RCA are usually limited to approximately 25% of the total coarse aggregate content. The incorporation of higher volumes of RCA is a field of discussion, primarily regarding the durable behavior of concrete. This study analyzes different transport properties of concretes with compressive strength of 20-50 MPa prepared with variable contents of RCA (0, 25, and 75%). Eight types of RCA were obtained from concretes incorporating four different natural coarse aggregates: granitic, basaltic, quartzitic crushed stones, and siliceous river gravel. Capillary absorption, water penetration, and chloride diffusion tests were conducted. The variation of transport properties with concrete compressive strength and the effect of RCA content on the variability of transport properties were analyzed. According to the results, the durable behavior of recycled concretes is different according to the transport mechanisms to which they are exposed and this behavior can match that of concretes made with natural coarse aggregates. (C) 2014 American Society of Civil Engineers.