Response Analysis of Reinforced Concrete Block Infill Panels under Blast

Increased exposure to the detrimental effects of blast events has led to the release of several guidelines and the recent publication of two North American standards that provide guidance on the hardening and performance quantification of structures subjected to this type of loading. The safety and security logistics and the high cost associated with performing experimental blast testing has led to a number of codes and guidelines accepting the use of simplified dynamic modeling techniques to analyze the response of structural components. Past research in blast-masonry interaction has primarily focused on the strengthening and retrofit of existing unreinforced masonry wall systems, whereas research related to evaluating the blast response of reinforced masonry (RM) has been limited. The focus of this study is to evaluate the accuracy of using simplified dynamic modeling techniques to predict the blast performance of nonintegral RM infill walls. To evaluate the accuracy of the simplified dynamic models, the predicted response values are compared with results obtained from experimental blast testing of RM infill walls that cover a range of wall design parameters, charge weights, and standoff distances. The combinations of charge weights and standoff distance presented a range of scaled-distances, reflecting different explosive threat levels, which were selected to induce different damage levels in the RM walls. Results from this study indicate that the wall peak deflection response can be accurately predicted using the simplified dynamic models, which was used to generate RM infill wall performance charts for a range of reinforcement ratios. Additionally, it was found that the complex response of the nonintegral infill walls investigated in this study is bounded by two common boundary configurations as verified by further analyses. The analysis results are expected to provide a better understanding of RM infill wall performance under blast loads and the performance charts can be used as a screening tool for existing walls and preliminary design of new construction under different design-basis threat (DBT) levels.