Carbonation rate and reinforcing steel corrosion of concretes with recycled concrete aggregates and supplementary cementing materials

Because of the significant environmental impact that the concrete production causes, and as sustainability contribution for this industry; presently some improvements are being implemented in its durability and its components are been replaced for alternative recyclable materials. Concrete carbonation is one of the main causes of reinforcement electrochemical corrosion. Coarse Recycled Concrete Aggregates (RCA) and Supplementary Cementing Materials (SCM) such as fly ash and silica fume were used to produce durable and environmentally friendly concrete and for the evaluation of its carbonation depth and carbonation-induced reinforcement corrosion when it is exposed to accelerated conditions. The depth of carbonation was observed by spraying a phenolphthalein solution on the fresh broken concrete surface. The corrosion rates of steel embedded in these concretes have been measured by the lineal polarization resistance technique. The results indicate that to use RCA and SCM increase the carbonation depth and corrosion current density