Parameters influencing water permeability coefficient of cracked concrete specimens

Permeability test methods have been used for measuring the permeability coefficient of homogeneous porous materials, but it has not been verified whether the methods are appropriate to evaluate permeable characteristics of cracked concrete. The objective of this study is to validate the permeability test method for cracked concrete specimens and investigate influential parameters on the test results. Intensive parametric studies have been done for samples with various crack types, crack widths and water heads. The results show that water head and crack width are the factors most influential on the permeability coefficients. It is observed that the actual pressure gradient that is applied between inlet and outlet of the specimen varies from 60% to 100% of the total water head due to the existence of head losses in the test device, which can lead to underestimation of the permeability coefficient. It is suggested that these head losses in the test system can be minimized by decreasing the total water head or adjusting the geometry of the test device.