Effect of carbon fiber waste on steel corrosion of reinforced concrete structures exposed to the marine environment

Abstract

This study experimentally investigates the possibility of using chopped carbon fiber waste for mitigating steel corrosion in reinforced concrete structures. Chopped carbon fiber waste was surface treated with epoxy to address the uniform dispersal of soft chopped carbon fiber into the cement mixture and prevent galvanic coupling between chopped carbon fiber and steel bars. The steel corrosion of reinforced concrete structures with different chopped carbon fiber percentages has been analyzed via electrochemical corrosion measurements, load-displacement curves and microscopy observation analysis. reinforced concrete beams were subjected to sustained point loading, a mass fraction of 3.5% Sodium Chloride marine wet-dry cycle and 50 °C environments for 360 days. A decrease in corrosion rate was observed in the beams with chopped carbon fiber waste compared to the control beams without chopped carbon fiber. The decreased corrosion rates in beams with 2.5% and 5% chopped carbon fiber (mass fraction of cement) were approximately 20% and 10%, respectively, compared to the beams without chopped carbon fiber. The ultimate strength of beams with 2.5% chopped carbon fiber and 5% chopped carbon fiber was increased by 25% and 17% compared to the control beams. Therefore, chopped carbon fiber waste could be used in reinforced concrete structures for reducing corrosion activity.