Numerical and experimental assessment of unsaturated fluid transport in saw-cut (Notched) concrete elements

The long-term durability of concrete is related to its ability to impede or reduce fluid transport. The long-term durability performance of concrete pavement can be dramatically influenced by the ingress of water or other fluids at saw-cut joints. Research is needed to better understand the role of complex geometries, like saw-cuts, on fluid transport. This paper uses x-ray attenuation to study the unsaturated fluid transport in systems containing a saw-cut (notch). The rate of water transport is greater in the direction perpendicular (i.e., horizontal) to the wall of the saw-cut when compared to the penetration below the tip of the saw-cut. This can be explained by the geometry of the source. To study the influence of fluid properties on transport, two fluids were tested with dramatically different viscosities and surface tensions. The results indicate that for the solution with higher viscosity and lower surface tension the absorption rate is reduced significantly. A finite element based code (Hydrus) is used to simulate the unsaturated flow based on solution of Richard's equation. Results of simulations show good agreement with experimental results and confirm the effects of the geometry of the saw-cut on fluid transport.