Test on Corrosion Resistance of GFRP Anchor Bolt

Abstract

Steel is commonly used as the materials of anchor bolts in permanent anchoring works. The nature the steel anchor bolt easy to be corroded, however, poses a serious potential safety hazard to the anchoring system mainly including steel anchor bolts. To use GFRP(glass fiber reinforced polymer) anchor bolts instead of reinforcing bars is an effective means to deal with corrosion. Based on the test of accelerating aging in high solubility, the physical and mechanical performance tests are conducted on GFRP bolts in normal, acid, alkalis and salt conditions, from which the change law of physical and mechanical property can be studied for bolts in different corrosion conditions. As shown from the test results, the weight of GFRP bolt is reduced after it is corroded and the rate of weight loss increases as the corrosion time extends. Thick swelling can be seen on bolts in alkalis conditions. Loss rate of tensile strength and increase rate of elastic modulus are greater in alkalis conditions than in acid conditions, the former reaching 13.76% and the latter 9.83%. As for bolts in acid conditions, tensile strength decreases as the corrosion time extends while the rate and amount of loss is less than that of bolts in acid and alkalis conditions. The tensile strength decreases as the solubility of corrosion solution increases. The loss rate of tensile strength is the most for bolts in alkalis conditions; it comes second in acid conditions and the least in salt conditions. The elastic modulus of bolts in acid conditions and alkalis conditions increases while the rate is comparatively low as the solubility gets higher. Elastic modulus of bolts in salt conditions decreases as the solubility rises with lower rate and smaller amount of loss. These results supply test foundation for application of GFRP bolts in complicated geological conditions.