Effect of Damage on Moisture Transport in Concrete

This paper presents the results of an experimental and analytical study on the effect of distributed cracks (damage) on moisture transport in concrete. Specifically, the writers investigate the following: (1) how damage affects the saturated and unsaturated transport and electrical resistivity, (2) whether one-dimensional (1D) analysis based on the sharp front (SF) theory can explain the relation between the saturated and unsaturated transport in damaged concrete, and (3) which transport mechanism is more sensitive to damage. Conceptual models are developed based on damage mechanics and fluid transport to explain the experimental data. Material constants are also provided for numerical modeling of unsaturated transport in damaged concrete. The results show that damage differently affects each of the transport mechanisms, and saturated hydraulic conductivity is more sensitive to damage as compared to sorptivity and electrical resistivity. The simplified 1D analysis, based on the sharp front theory, does not adequately describe the effect of damage on unsaturated transport. The developed conceptual models can be used to qualitatively describe the effect of damage on transport properties of concrete.