Experimental and numerical analysis on dry and saturated concrete behaviour under high pressure confinement

Abstract
This study focuses on the identification of concrete behavior under severe triaxial loading in order to better evaluate the vulnerability of sensitive infrastructure to near-field detonations or ballistic impacts. For the purpose of reproducing high stress levels with well-controlled loading paths, static tests have been conducted on concrete samples using a triaxial press presenting very high capacities (stress levels of around 1 GPa). Massive concrete structures, such as bridge piers, dams and nuclear reactors, could retain a quasi-saturated core throughout most of their lifetime, even though their facing dry very quickly. The objective of this article is to evaluate experimentally and numerically the effect of the saturation ratio on concrete behavior under high confinement. Triaxial test results are presented for concrete samples over a saturation ratio range extending from dried to quasi-saturated. The subsequent analysis of results show that the saturation ratio exerts a major influence on concrete behavior, particularly on both the concrete confined strength capacity and shape of the limit state curve for saturation ratios above 50%. This analysis also highlights that while the strength of dried concrete strongly increases with confining pressure, it remains constant over a given confining pressure range for either wet or saturated samples. At the end, this article show first simulations on projectile penetrations in dried and saturated concrete slabs with PRM model. These numerical results show the water saturation effects on projectile penetration capacity in the structure according to levels of saturation.