Probabilistic Time-Dependent Ratio of Cost to Benefit for Silane Treatment on Chloride-Exposed Concrete Structures

Abstract

This study presents use of an approach which links the Latin Hypercube technique with Crank-Nicolson based finite difference approach for probabilistic assessment of chloride diffusion through silane-treated concrete. There are six random variables; (1) surface chloride, (2) diffusion coefficient, (3) first application time, (4) subsequent application time, (5) effective duration, and (6) cost of silane treatment. By different application times, three repair strategies are proposed. With silane treatment, the diffusion of chloride ions in silane-treated zone is retarded leading to the extension of the time which the chloride content at a threshold depth reaches the critical value of rebar corrosion and concrete cracking. Based on this extension, the time-dependent risk of rebar corrosion and concrete cracking is defined, and the time-dependent ratio of cumulative cost of silane treatment to benefit (percent reduction of the risk) is calculated. And, the best strategy based on the ratio of cost to benefit is justified.