Water transport in concrete damaged by tensile loading and freeze-thaw cycling

In service, concrete can develop cracks or microcracks that can influence the transport of liquids and ions. This paper describes an investigation of fluid transport in concrete damaged by tensile loading or freeze-thaw cycling. Acoustic emission was used to quantify the extent of damage in the specimens exposed to tensile loading while resonant frequency was used to quantify the extent of damage in the specimens exposed to freezing and thawing. Water absorption was measured in the damaged concrete. The presence of freeze-thaw damage increased both the initial sorptivity and total water absorption. Electrical conductivity was measured and found to increase in a bilinear fashion with freeze-thaw damage. A knee point in the electrical conductivity versus freeze-thaw damage curve was observed when the dynamic modulus degraded to 75% of its initial value, which appears to correspond with the coalescence of cracking. Mechanical loading was found to only increase water absorption on a local level, but it did not substantially influence the overall water absorption.