A model for computation of leakage through damaged concrete structures

Predictive computation of fluid flows through concrete structures subjected to mechanical and/or thermal loading requires detailed description of cracks. A series of experiments were performed to obtain statistical data on the crack profile. For that purpose, concrete specimens were cracked using bending tests. Three concrete mixtures with the same aggregate were used to illustrate the difference between normal and highperformance concrete. Three-point and four-point bending tests were conducted so that the role of the stress gradient on the roughness was assessed. The obtained cracks were scanned and their geometry was digitized and statistically studied. A probabilistic crack-generation model based on previous results allowed to generate crack patterns at the microscale level according to the given field of damage at the macroscale level. The obtained computed crack pattern was used for flow computation. It was shown that the probabilistic model produced statistically representative results for the flow computation. The influence of parameters like crack opening, pressure, and roughness were then evaluated