Water permeability of engineered cementitious composites

The water permeability of a unique class of high performance fiber reinforced cementitious composites (HPFRCC) called engineered cementitious composites (ECC) is investigated. These composites are deliberately tailored using microcmechanical design principles to exhibit pseudo-strain-hardening characteristics in uniaxial tension, up to greater than 4% strain. While undergoing tensile deformation, microcracks are designed to saturate the specimen rather than localize into large cracks. This tendency to form microcracks, which are experimentally shown to be approximately 60 μm in width, allows ECC material in the cracked state to maintain water permeability similar to that of uncracked concrete or mortar, and magnitudes lower than cracked reinforced mortar or concrete. It is also shown that the self-healing properties of cracks within ECC material significantly aids in reducing the coefficient of permeability of cracked ECC.