Fragmentation of Heat-Strengthened Glass: Implications for Glass Not Conforming to ASTM C1048

Abstract

Heat-strengthened glass with residual surface compressive stresses above those allowed by ASTM C1048 was installed in a curtain wall in the mid-Atlantic region of the United States. To address building ownership’s concerns regarding postbreakage glass fallout, fragmentation tests were performed using a protocol adapted from EN 1863. Consistent with previous research, no significant difference in fragmentation was noted between samples with residual surface compressive stresses conforming to ASTM C1048 and those with residual surface compressive stresses well beyond the established ASTM limits. Simplistic analyses revealed that, under certain modes of failure, risk of glass fallout is comparable for conforming and nonconforming heat-strengthened glass. The completed testing also has implications for glass quality control processes.