Empirical Based Concrete Masonry Pressure-Impulse Diagrams for Varying Degrees of Damage

Abstract

Concrete Masonry Unit (CMU) walls represent one of the more prevalent exterior construction materials for conventional buildings worldwide. Due to their weight and low blast capacity, CMU walls present a significant hazard to building occupants when subjected to intentional or accidental blast loads. A recent study showed that more than half of the buildings within the US Armed Forces are constructed using reinforced or unreinforced masonry walls. CMU construction is also common within petroleum and chemical plants where the consequences of accidental explosions on occupied buildings must be addressed as required by OSHA 29 CFR 1910.119. The Office of Special Technology, Technical Support Working Group with technical oversight from the Defense Threat Reduction Agency sponsored a study to compile all known blast tests on masonry wall panels. The data was scaled to facilitate empirical derived pressure-impulse (P-i) damage curves, which removed a significant degree of conservatism associated with previous P-i curves developed in the 1980’s. These curves were updated in a study sponsored by the Army Corps of Engineers, Protective Design Center. These updated response curves have been embedded into fast running blast vulnerability codes to quickly assess masonry hazards to building occupants. There is an interest that these assessment codes include similar validated P-i diagrams for various building retrofit options so retrofit costs can also be estimated expeditiously. This paper discusses the development of P-i response curves for common masonry wall construction upgraded with E-glass.