Experimental Study on Tensile Strength Degradation of Carbon Fiber Reinforced Polymer (CFRP) Composite in Alkaline Environment

Carbon fiber reinforced polymers (CFRP) composites are being extensively used in the civil engineering industry in recent years because of their superior characteristics. CFRP composites comprise carbon fibers that are resistive to corrosion and epoxy resin matrix which is highly vulnerable to moisture and corrosive ions. Therefore, the durability of these composites in harsh environment conditions especially in the alkaline environment still needs to be studied. Wastewater treatment plant tanks, sewage networks and marine structures using this technology to strengthen structures is a great challenge as alkaline ions present in these environments possess a serious threat to the CFRP system. In this study, a comprehensive accelerated program was conducted to assess the tensile capacity deterioration of CFRP composite subjected to an alkaline solution with a pH value of 12.6. Microstructure analysis was carried out using Scanning Electron Microscope (SEM) to identify in-depth material disintegration. A maximum tensile capacity reduction of 11.5% was identified and SEM images revealed damage in the resin matrix because of moisture and alkaline ion intrusion.