Experimental Investigation on Monolithic Tempered Glass Window Responses to Blast Loads

Monolithic glass is one of the most commonly and widely used materials for structural glazing in buildings. Due to its relatively low strength and brittle nature, monolithic glass window is often the most fragile part of a structure when subjected to air blast wave. The breakage of glass window under explosion always leads to enormous injuries and fatalities as a result of ejecting glass sharps flying at high speed towards people in the occupied area. For better protection of building occupants, it is necessary to fully understand monolithic glass responses under blast pressure. In this study, a series of full-scale field blasting tests were carried out to investigate monolithic glass window responses to blast loads. Typical windows with tempered glass panels and steel strip boundaries were mounted onto a reinforced concrete (RC) frame purposely constructed to support the window specimens for the tests. TNT explosives of different weights were detonated at different stand-off distances in front of the window. Window responses were monitored with high-speed cameras and linear variable displacement transducer (LVDT). Pressure sensors were used to measure the reflected pressure. Glass window failure patterns and associated glass fragments were recorded and analyzed. The tested window performances were compared with the predicted results based on ASTM and UFC standards, as well as previous testing results. Based on the testing data, criteria for tempered glass crack and fracture under blast loadings were formulated.