Experimental Study on Chemical Resilience of Glass Reinforced Polymer Pipes for Sewage Applications

A comprehensive understanding of composite pipe corrosion behavior is essential due to their exposure to diverse chemical environments. This study examines Glass Reinforced Plastic (GRP) composites, commonly employed in underground construction and industrial applications, with a particular emphasis on the rehabilitation of aging sewage pipelines. The investigation focuses on assessing the chemical durability of a multi-layer GRP material reinforced with polyester resin. The chemical resistance of individual layers and the composite as a whole are evaluated before and after immersion in various chemicals for periods of 30, 60, 90, and 180 days. The chemical environments are designed to replicate in-service conditions, including exposure to Sulphuric acid (H₂SO₄), Sodium hypochlorite (NaClO), Methyl ethyl ketone peroxide (MEKP), distilled water, Sodium chloride (NaCl), Propanone (C₃H₆O), Cobalt Octate, and Dimethylacetamide (DMA). Mass loss measurements are used to evaluate changes in chemical composition. The observations from this study assist in estimating the long-term structural health of composite pipes exposed to harsh chemicals found in sewage water.