A Blast Mitigation Technique for Unreinforced Masonry: An Experimental and Computational Analysis

Conventional unreinforced masonry has minimal ability to resist high-energy hazards such as those created by blast loads. Consequently, blast mitigation is essential for unreinforced masonry structures. This paper will summarize research conducted for the Department of Homeland Security (DHS) by the U.S. Army Engineer Research and Development Center (ERDC) and Lawrence Livermore National Laboratory (LLNL) relating to retrofitting unreinforced masonry for blast resistance. The objective of this research was to determine the most effective mitigation scheme capable of resisting blast-induced damage due to near-contact detonations to unreinforced masonry. Sub-scale masonry test specimens were fabricated to test three mitigation concepts subjected to the same explosive threat. These damage mitigation techniques were evaluated based on their ability to prevent breach and reduce deformation in unreinforced masonry. Based on this evaluation, a mitigation concept was selected and validated using full-scale field experimentation and computational modeling. These experimental data were used to validate predictions of the computational models. Experimental results are compared to numerical predictions for both sub-scale and full-scale experiments. This research will provide critical information regarding mitigation schemes for unreinforced masonry and assist agencies in determining the most efficient way to harden masonry structures against blast loads.