Durability of concrete incorporating recycled coarse aggregates: carbonation and service life prediction under chloride-induced corrosion

The use of recycled aggregates (RA) is growing due to the environmental problems associated with extracting natural aggregates (NA) and the disposal of construction and demolition waste (CDW). However, the service-life prediction of recycled coarse aggregate concretes remains incipient. Thus, this study aimed to evaluate the effects of different replacement contents of NA by RA (25, 50, and 75 wt%) on physical (water absorption, porosity, and bulk density), mechanical properties (compressive strength and modulus of elasticity), microstructure (evaluated by X-ray microtomography), accelerated carbonation, and chloride penetration of concrete. A service life prediction analysis of RA concretes was conducted based on the chloride profile obtained and considering the application of different concrete surface treatments. The RA contents evaluated increased the carbonation and chloride diffusion coefficients by 75.7% and 43.0%, respectively, compared to the reference concrete. Nevertheless, reductions of approximately 50% on the critical chloride concentration depth of RA concretes are estimated considering the application of acrylic-based surface treatment. Therefore, applying surface treatments is promising to increase RA concretes' durability and service life, contributing to its wide use and dissemination feasibility.