The effects of aging in seawater and SWSSC and strain rate on the tensile performance of GFRP/BFRP composites: A critical review

Abstract

• The tensile properties of GFRP/BFRP after exposure in sea water/SWSSC are discussed. • The degradation degree increases with the exposure time, temperature and alkalinity. • The impact strength and fatigue life are reduced due to the exposure in seawater. • The dynamic performance and failure mode are obviously influenced by strain rate. • The future research needs are proposed for the FRP used in seawater/SWSSC. Replacing metallic materials (typically carbon steel bars) with fiber reinforced polymer (FRP) composites to reinforce marine concrete structures can effectively resolve the corrosion issue of carbon steel due to external chloride ions and moisture. However, the corrosion-free nature of FRP material cannot guarantee its desirable durability in the marine structures. In order to better understand the durability performance of FRP composites, this paper summarizes the quasi-static tensile properties of FRP composites after exposure in simulated seawater and seawater sea sand concrete (SWSSC) environments, and the dynamic performance of the FRP materials. It is found the degradation degree of FRP composites increases with the exposure time, temperature, stress level and alkalinity/salinity of the immersion solution. Currently, the investigations on the dynamic tensile properties of FRP composites after long-term exposure tests are quite limited. Hence this study identifies the possible research needs by summarizing the investigations on the degradation of FRP’s dynamic performance after seawater exposure and the strain rate sensitivity of glass/basalt fiber reinforced polymer (GFRP/BFRP) composites under dynamic loading. The impact strength, Young’s modulus and fatigue life will all be diminished due to exposure in seawater. And both the mechanical performance and failure mode of the FRP composites are obviously influenced by the applied strain rate. This study identifies the current knowledge gap and can serve as a valuable reference for further investigation on the long-term performance, especially the long-term dynamic tensile properties of FRP composites in seawater and SWSSC environments.