Experimental investigation of the synergistic effects of moisture and freeze-thaw cycles on carbon fiber vinyl-ester composites

Abstract

Carbon fiber-reinforced vinyl-ester polymer composites are increasingly used as structural members in applications (e.g., marine crafts and offshore structures) where they can be frequently exposed to the environmental elements of moisture and cold temperature fluctuations that cause freeze-thaw cycles. These harsh elements can individually and possibly synergistically damage carbon fiber-reinforced vinyl-ester composites. More importantly, their damage can accumulate over time and significantly degrade the structural properties, long-term integrity and durability of carbon fiber-reinforced vinyl-ester composites. This work experimentally investigates the individual and cooperative degrading effects of moisture and freeze-thaw cycles on the structural properties of carbon fiber-reinforced vinyl-ester composites, particularly on their flexural stiffness and strength. Results show that the combined damaging effects of moisture and freeze-thaw cycles are more significant than their individual effects, confirming the synergy between the damage mechanisms of the two elements.