Mechanical behavior of GRP pressure pipes with addition of quartz sand filler

In comparison with steel, concrete, and polymeric pipes, glass-reinforced plastic (GRP) pressure pipes use more expensive raw materials. Thus, despite of their attractive structural performance, mainly in terms of mechanical strength combined with low weight, the higher cost can be a limitation in many applications. In this scenario, an alternative to reduce the final price of GRP pipes is the addition of quartz sand filler. In this experimental and numerical study, filament-wound E-glass/polyester pipes with nominal inside diameter of 300 mm and wall thickness of 5.7 mm were produced with the incorporation of quartz sand as filler and tested to failure under internal pressure. The mechanical behavior of the composite pipes was evaluated experimentally, throughout short-time hydraulic failure pressure tests, as well as using finite element analysis (FEA). In the FEA simulations, the shell wall was modeled as an axisymmetric layered orthotropic material. A good agreement, varying from 96% to 98%, was obtained between the average hydraulic failure pressure measured and FEA predicted failure pressures, using Tsai—Hill and Hoffman failure criteria, respectively.