Increases in ultimate strengths of 23.7 (Series I) and 24.6 (Series II) percent under dynamic loading were obtained. Theoretical slab strengths were determined. Modification of the equations used allowed good predictions of tensile membrane resistance of the static slabs. The equations were used to predict peak pressures sustained by the dynamic slabs.

Two studies, one theoretical, the other experimental are reported. The strength and behavior of restrained reinforced concrete slabs were investigated under both static and dynamic loads. Nine 6-foot-square slabs were tested: six under uniform static pressure and three under long-duration dynamic loads. Steel reinforcement ranged from zero to 1.33 percent. The slabs failed initially in a flexural mode, followed by total collapse at a much greater deflection. The thinner slabs deflected more than 2.5 times their thickness under both types of loading. The theoretical study deals with a square slab, restrained against rotation and longitudinal movement at the edges. The study covers static resistance, failure criteria, size and extent of fragments, and design recommendations. An analytical method is developed to predict the static resistance, deflection, and longitudinal restraining thrust at ultimate failure. The resistance and behavior of longitudinally restrained square slabs are predictable, and if properly designed can resist dynamic loads effectively and more economically than those with no longitudinal edge restraint. (Author).