Comparative Study On Corrosion Rates In Concrete Made Of Recycled-Concrete And Recylced-Brick Aggregate

Abstract

Recycling waste materials play a crucial role in minimizing the environmental impact caused by the concrete industry. However, uncertainties exist regarding the durability of recycled aggregate concretes when exposed to harsh conditions. This study conducted comparative research on the long-lasting properties of concrete containing recycled aggregates (RA). To produce RA on a global scale, discarded concrete from construction sites was crushed. Various types of concrete mixes were examined, including a control group with only natural aggregates (NA), and others that incorporated NFA and RCA (substituting 20%, 40%, 60%, 80%, and 100% RCA). The investigation focused on measuring the electrical resistivity (ER) in chloride-contaminated environments, which indirectly assesses concrete corrosion rates. The results revealed a decrease in ER with higher levels of RCA incorporation. In terms of corrosion testing, the ER of 100% RCA concrete ranged from 60% to 90% of the ER observed in the control sample. However, the decrease in ER for RFA concrete was significantly greater compared to the RCA concrete. Specifically, one study demonstrated that replacing 20% of the FA with recycled materials reduced the ER by 25%, while utilizing 100% RFA resulted in a reduction of over 60% in ER.

Keywords

• recycled coarse aggregate; electrical resistivity; corrosion rate