Influence of water gradient on surface wave measurements in concrete
Abstract
The knowledge of water gradient in cover concrete is of primary importance for the estimation of concrete durability. In this paper the influence of water gradient on surface wave phase velocity dispersion curves is studied on concrete slabs during water absorption and drying. The comparison of surface wave phase velocity dispersion curves measured at various times corresponding to different water gradients shows that surface waves are sensitive to
water ingress. Furthermore, taking information from embedded sensors and gammadensimetry, and using master curves established for an homogeneous water content, it is possible to predict the surface wave phase velocities variations. This suggest that, eventhough the variations of surface wave phase velocity are only a few %, the comparison to a reference state should make it possible to follow variation of water gradient.