Fracture of glass-reinforced plastic pipes of mixed wall construction under pressure loading

Hand laid-up straight pipes of 250 mm inside pipe diameter, constructed from polyester resin matrix and E-glass reinforcement supplied in two different combinations of chopped strand mat (CSM) and woven rovings (WR) have been tested to destruction under internal hydraulic pressure. Results are compared with those from a similar pipe constructed from CSM only and one constructed by wrapping CSM layers on a PVC (polyvinyl chloride) liner. Failure pressures for the different constructions are compared with each other and with design pressures associated with two design codes. Features of the fracture patterns are noted, following an extensive microscopic examination of the straight pipes.