Chloride permeability and the caused steel corrosion in the concrete with carbonated recycled aggregate

Abstract

Carbonation treatment was recently developed to enhance the properties of recycle concrete aggregate and prepared concrete, but the durability of concrete with carbonated recycled aggregate have received little consideration in the previous studies. This study investigates the chloride permeability and the resulting steel corrosion of concrete with carbonated recycled fine and coarse aggregates, and the effects of recycled aggregate quality on chloride permeability are presented. The carbonization treatment was first applied to recycled aggregate to prepare carbonated recycled aggregate; then, the chloride permeability and steel corrosion experiments were conducted on concrete with carbonated recycled aggregate. The results exhibit that carbonation treatment improves the physical performance of recycled aggregate, which results in an increase in the compressive strength of preparing recycled concrete. Concrete with carbonated recycled aggregate has a lower chloride permeability than that with non-carbonated recycled aggregate, and the improvement in the chloride permeability resistance is more obvious for concrete with carbonated recycled fine and coarse aggregates. In particular, the improvement of chloride permeability resistance becomes more distinct with the reduction of recycled aggregate quality. The addition of carbonated recycled aggregate reduces the steel corrosion risk of reinforced recycled aggregate concrete, and the chloride permeability and steel corrosion risk follow a linear trend.