INFLUENCE OF TIME-DEPENDENT DIFFUSION ON SERVICE-LIFE ESTIMATES FOR REINFORCED CONCRETE EXPOSED TO CHLORIDES

摘要

The diffusivity of concrete, like many other concrete material properties, changes as the concrete ages or matures. Recent studies have shown that measured diffusion coefficients may change by more than one order or magnitude during the typical service life of a concrete structure. Despite this, many of the currently available models for predicting chloride penetration into concrete assume that diffusion is constant with time and this leads to considerable error in service-life estimates. This paper presents data to demonstrate the importance of accounting for the time-dependent nature of diffusion and discusses approaches for determining relevant indices for service-life calculations.