Strength of New Heat Treated Window Glass Lites and Laminated Glass Units

The strengths of certain window glass types, window glass constructions, and window glass treatments are poorly understood by the window-glass-design community. Many assumptions are employed in defining the design strengths of various window-glass types, constructions, and treatments such as laminated glass, heat-strengthened glass, and insulating glass. As part of its ongoing research program into the strength of window glass, the Glass Research and Testing Laboratory at Texas Tech University conducted strength tests on fully tempered monolithic glass lites, heat-strengthened monolithic glass lites, fully tempered laminated-glass units, and heat-strengthened laminated glass-units. The objective of these tests was to determine the strengths of these glass types and constructions relative to monolithic annealed glass lites with the same nominal dimensions. The failure strength data resulting from these tests differ significantly compared to the assumptions underlying design strengths proposed by ASTM for these glass types and constructions.