Resistance of SC Walls Subjected to Missile Impact: Part 3. Small-Scale Tests

Reinforced concrete (RC) walls are commonly used for protective structures against blast or impact loads. Steel-plate composite (SC) walls – which consist of steel faceplates with a concrete infill, tie bars to connect the faceplates and steel-headed stud anchors for composite action – have demonstrated advantages over RC walls: easy to modularize, decreased construction time and excellent resistance for blast loads and missile impact. Recognizing these benefits, SC structures are being used in safety related facilities in the current generation of nuclear power plants. Although a variety of SC walls have been experimentally and numerically tested to evaluate their resistance to missile impact, the focus of previous tests was typically on understanding behavior rather than developing methods to design perforation resistant walls. Using the available database of previous tests, Bruhl et al. (2015) proposed a rational three-step design method to prevent perforation of SC walls for various missile threats. While this design method was validated using tests available in the literature, it has not been systematically evaluated and validated by an experimental program designed to quantify its inherent conservatism and refine the accuracy of the method. In this paper, results from an experimental program to meet this need is described. The program was designed to evaluate the three-step design method, confirm its accuracy and better quantify any inherent conservatism of the method. The test series included a variety of design parameters and projectile size and impact velocities.Post-test damage of the SC walls was quantified and observed damage modes and the extent of damage is described in this paper. Comparison of experimental results to the expected result based on the three-step method is presented and conservatism contained in the method is quantified and sources of this conservatism are discussed