Structural Performance of Recycled Aggregate Concrete Corroded by Accelerated Corrosion

The practical use of recycled aggregate as a structural member for environmental protection and resource conser-vation, requires studying the structural behavior of recycled aggregate concrete in its aging state. Therefore, in this study, structural performance tests were performed by simulating the aging of recycled aggregate concrete through corrosion of rebar. As an experimental variable, the aging simulation process was set to 6 stages with corrosion rates of 0, 2, 4, 6, 8, and 10%. Flexural and bonding performance tests were conducted to determine durability after corrosion. The actual corrosion rate was lower than the expected corrosion rate, and the crack width was larger than that of natural aggregate concrete at similar thickness of concrete cover and corrosion rate. As the corrosion rate increased, both the flexural and bonding performance specimens showed a tendency to decrease in yield strength, and a brittle load-displacement curve was observed. Characteristically, the specimen with a corrosion rate of 1~2 % showed the highest maximum load, bonding strength, and ductile fracture behavior in each experiment. Also, it was judged that the continuity of corrosion cracking affects the performance degradation, rather than the corrosion crack width. In addition, brittle fracture behavior caused by corrosion cracking, or the characteristics of specimens with a specific corrosion rate showing high structural durability, seemed to be similar regardless of the type of aggregate.