Experimental study of weathered tempered glass plates from the northeastern United States

The authors performed an experimental study with weathered fully tempered monolithic glass loaded to failure under controlled conditions. The 14 specimens in the study originated from the northeastern United States. The specimens were loaded with monotonically increasing pressure until fracture occurred in accordance with the ASTM E997 test method. The recorded failure load time histories were converted to equivalent 3-s failure loads using a modified load-transformation-integration method that incorporates residual compressive surface stress. Variations of the residual compressive surface stress measurements are presented for each specimen, and the effect that the variations in residual compressive surface stress have on the equivalent 3-s failure load calculations are also explored. Equivalent 3-s failure loads are shown to be proportional to the measured residual compressive surface stress. The equivalent 3-s failure load is compared to the load resistance calculated using ASTM E1300, and the modified method for treated glass is presented. The mean equivalent 3-s failure loads were 150% larger than the load resistance calculated using ASTM E1300 and 50% larger than the load-resistance predictions of the modified method, which suggests that fully tempered glass is stronger than predicted by ASTM E1300 and does not weather like annealed glass.