Quantitative analysis of the effect of coarse aggregate diffusivity on reinforcing steel corrosion initiation with a finite element model

The purpose of this paper is to explore and compare the influence of diverse coarse aggregate (CA) diffusivities on reinforcing steel corrosion initiation through a quantitative modeling analysis approach.

Finite element analysis was used to solve two‐dimensional chloride diffusion processes, which follow the Fick's second law within the concrete cover. Two non‐dimensional time‐derating factors were employed to quantify the time‐to‐corrosion of steel rebar, T_i, for different models.

The finite diffusivity CA exhibits variable effects on T_i, depending upon: diffusivity ratio between the CA and mortar; CA type; reinforcement corrosion resistance; and cover thickness. The intent of the effects are expressed quantitatively and their implications discussed.

The methodology and results presented in this paper provide insights on the variable reinforcement T_i values as a function of CA diffusivity. The approach employed herein provides an effective tool to select CA materials for reinforced concrete structure where chloride‐induced corrosion is a concern.