Reliability estimation of recycled aggregate concrete structure subjected to carbonation

The life-cycle assessment of reinforced concrete structures through economic, environmental, and social impact across the whole service life is now gaining more and more interest in civil engineering. The mechanical properties and long-term performance of structures using recycled aggregate concrete (RAC) were reported to be weaker than those of structures using natural aggregate concrete (NAC) given the same mix proportion. However, the studies on the durability of RAC subjected to carbonation are scare and limited in the literature. The main purpose of this study is to present the computational procedure for the life-cycle reliability estimations of NAC and RAC structures exposed to carbonation. The experimental results of NAC and RAC under the diffusion of carbon dioxide (CO2) are obtained from the literature reviews. A durability design factors and criterion for designing concrete structure using RAC that satisfy the target failure probability is presented. The effects of concrete properties (i.e. water to cement ratio) and concrete cover on the estimation of reliability of structures using natural and recycled aggregate are investigated in an illustrative example.