Exponentially aging functions coupled with time-dependent chloride transport model for predicting service life of surface-treated concrete in tidal zone

Abstract

This study aims at proposing exponentially aging functions coupled with time-dependent model of surface chloride and diffusion coefficient for concrete with surface treatment. The proposed functions enable to avoid three limitations in a previous study; inconsistency of material aging behavior, reliance on available surface chloride functions, and unpredictability of service life in some case. The proposed functions are applicable to concrete sealing and coating models introduced in this study. As a tool, the finite difference and the downhill simplex methods in Fick-based approach is developed. The proposed functions are validated by comparing to experimental results of five surface treatments applied on tidal-zone concrete, and other studies. Accordingly, the service life of concrete with surface treatment can be predicted. To examine the aging, a terminology called “remaining effect of surface treatment” is defined. Limitation of the proposed functions is discussed, and the ratio of aging functions is proposed for sensitivity analysis.