Permeability Degradation of Stressed Concrete Considering Concrete Plasticity

Abstract

Permeability of concrete is usually measured in laboratory conditions without loading, which can be completely different from that in service. This paper presents a new method to determine the permeability coefficient of concrete under applied loading, considering concrete plasticity. A dissipated energy–based approach is proposed to determine the damage variables for the concrete damage plasticity model. The developed method is verified with experimental results, after which a parametric study is conducted to identify the factors that affect the permeability degradation. It is found in the paper that the applied load is the governing factor for permeability degradation of concrete, and that the permeability degradation is influenced by grade of concrete, aggregate size, thickness of the interfacial transition zone, and the shape of aggregates. The significance of the developed method is that it can determine the permeability coefficient of concrete as a function of time with various constituent combinations and under any applied stresses, which would otherwise be impractical with experimental techniques.