Post-test analysis of a piping penetration in a 1:6-Scale model of a reinforced concrete containment building

Abstract

In a scale-model overpressurization test of a reinforced concrete containment building, the steel liner proved to be the weak-link for preventing the escape of gas from the containment. During the experiment, a tear propagated through the liner along the edge of a thickened section that surrounded a piping penetration. The rate of leakage through this tear was so great that it made further pressurization of the model impossible. A post-test finite element analysis of the region where the tear developed indicates that the tear was initiated by high strains that developed locally near a stud anchor which attached the liner to the reinforced concrete. This conclusion is also supported by visual observations of the failed area and measurements of local thinning of the liner. The elevated strains near the stud anchor were caused by a shear force that was introduced to the liner through the stud. This shear force developed as the result of circumferential slippage between the liner and concrete caused by the presence of the thickness discontinuity in the reinforced area.