Effect of fly ash and corrosion on bond behavior in reinforced concrete

Reinforcing steel bar can exert its strength and ductility by bonding to concrete. However, corrosion of steel bars reduces the bonding effect. This study mainly investigated the coupling effects of fly ash (FA) and corrosion on bond behavior. The impressed current method was utilized to achieve the target corrosion degrees. Three crucial factors that have impact on bond behavior was considered, which were FA content, corrosion degree and stirrups. The bond behavior was discussed using the bond‐slip curves. The results showed that the slight corrosion (less than 2.1%) can improve the bond behavior, the supplement of 15% FA can result in a higher ultimate bond strength and to a substantial extent offset the reduction in bond strength owing to the severe corrosion of rebar. The effects of stirrups on bond strength mainly focused on fly ash concrete (FAC) and had an almost negligible impact on ordinary concrete. The results and discussions can be of great significance to establish the bond‐slip constitutive model under multi‐factor coupling conditions and also can give some important advices to the design of engineering structures.