Service life and environmental impact due to repairs by metakaolin concrete after chloride attack

Abstract

A Crank-Nicolson based finite difference approach is developed for numerical assessment of chloride diffusion in concrete structures with repairs. The repair by cover concrete replacement is applied at a critical time which the chloride content at a threshold depth reaches its critical value for initiation of rebar corrosion. This aims at corrosion-free condition of concrete structures. The critical time is defined as the repair time, which the CO 2 due to repair concrete production and replacement processing occurs. From the study, it is found that increasing the amount of metakaolin in repair concrete by 4%not only leads to longer service life extension after repairs and fewer repairs but also reduces the amount of CO 2 by 50%.