An underground Reinforced Thermosetting Resin (RTR) piping system used in firewater facilities experienced frequent ruptures from inside-out after 7 years of service at several locations. This work encompasses a material assessment study to potentially identify the root cause of the incidents. The assessment was conducted through a series of analytical and mechanical methodologies starting with visual inspection, Loss on Ignition (LOI), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), axial tensile testing and Environmental Scanning Electron Microscope (ESEM). Results revealed the presence of microdefects within the fiberglass/resin matrix, as well as unfilled spaces between fiber structures suggesting an uneven distribution of the resin throughout the pipe. These microdefects potentially resulted in a weakening of the mechanical, physical, and chemical properties of the RTR pipe leading to its overall performance degradation over time, which eventually led to its final rupture prior to its anticipated service life in the corresponding field operating conditions.
Finance, workforce, and asset integrity are all major factors played in the global transition initiative from the use of the corrodible metallic materials to the long-lasting non-metallic materials such as the composites. The three monolithic materials, in other words, materials made up of a single type of blocks which are the metallic, ceramic, as well as the polymeric materials have been major fields of interest for centuries. However, a more recent field of promising materials has emerged and been recognized, which is the composite materials. The early composite materials such as Carbon/Epoxy has been observed and taken in interest in the mid-20th century. Afterwards, the analysis and studies that have been done on the monolithic materials were then applied on the newly founded class of materials [1]. A composite is the heterogenic combination of two or more different materials without having them being mixed or dissolving one another [2]. Among the various known composites, the RTR has been displaying arising applications, one of them is the use of RTR piping system to replace stainless steel in the transportation of firewater. The glass fiber reinforces the epoxy resin making it a mechanically enhanced thermosetting composite, it is a thermoset since the type of resin used is that of a material that changes its properties as it heats up without reverting to the pre-heating characteristics [3].
