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.

Ultimate strength equations are summarized for square, simply supported reinforced concrete slabs, and these equations are used to predict the dynamic ultimate and collapse strengths of three slabs. The predicted strengths are compared with experimental results from airblast load tests, and the extent of damage to the slabs is shown under over-pressures approximately equal to the predicted strengths.

The objectives of this investigation were to study the strength and behavior of slowly (statically) loaded reinforced concrete slab-column connections and to determine the effect of rapid (dynamic) loading on the strength and behavior by comparison with the static test results. Nineteen full-scale models of a connection and adjoining slab area, consisting of a simply supported slab 84 or 94 inches square and 6-1/2 inches thick loaded concentrically on a 10- or 20-inch-square stub column at the center of the slab, were tested. The main variables were the amounts of reinforcement in the slab (p = 0.75 and 1.50 percent), the column size, and the loading speed. Eight specimens were loaded to failure statically, two were subjected to a very rapidly applied load of short duration, and nine were loaded to failure by a rapidly applied load with a rise time chosen to represent the conditions in a blast-loaded structure. The static test results are compared with 12 shear strength prediction methods. Differences between the mechanism of shear failure in slabs and beams are examined. (Author).