A probabilistic study on effective hydraulic sorptivity of concrete

In durability design of concrete structures using performance-based framework, hydraulic sorptivity of concrete can be used as a key indicator. In this paper, a probabilistic methodology considering variability of hydraulic properties of concrete components, namely the mortar, aggregates, and interfacial transition zone (ITZ), is developed. Evaluation of the effective sorptivity of concrete is based on a rigorous nonlinear finite element (FE) analysis at the meso-scale level, which is verified using available experimental results. Using the response surface method (RSM), a conceptual model relating effective hydraulic sorptivity of concrete to aggregate volume fraction and hydraulic properties of mortar and the ITZ is derived. The proposed probabilistic methodology can be used for durability design of concrete structures. It is found that for high aggregate volume fractions the variability of hydraulic sorptivity is high due to increasing volume of ITZ.