Specimens from a carbon-only FRP grid and a glass-carbon FRP grid with junctions at 100 mm spacing were exposed for up to a year to solutions of salt and alkali, UV radiation with wet-dry cycling, and freeze-thaw action. Their tensile and junction strengths were evaluated at 4-month intervals. The tensile strength of these specimens was found to remain unaffected by the environmental conditions whereas the junction strength was found to be sensitive to salt, alkali and freeze-thaw action. A second group of specimens was subjected to a sustained tensile stress while exposed to a saline-alkaline solution. The residual tensile strength of the specimens surviving a year's exposure was determined. Carbon-only specimens were found to lose a small fraction of their tensile strength whereas glass-carbon specimens failed within 1 to 17 weeks of exposure and loading.
展开▼
