Residual strength of fire-exposed glass-reinforced epoxy composite pipes

摘要

Glass-reinforced epoxy composite pipes were exposed to fire for predetermined time durations under dry and wet internal conditions of the pipe. Subsequently, a monotonic burst test was performed, in which the fire-damaged specimen pipes were pressurized internally. Then, a micrograph analysis was performed using scanning electron microscopy. Continuous reduction in the residual burst strength of the composite pipe was noted for both the dry and wet internal conditions. The wet specimens exhibited prolonged functionality compared with the dry specimens, as the water present inside the pipe lowered the temperature of the inner pipe walls and reduced the rate of matrix decomposition. The composite pipe failed owing to the weepage caused by the matrix cracking from the increasing intumescent char formation on the internal pipe surface.