| Steel corrosion is one of the principal problems present in reinforced concrete construction. Billions of dollars are spent annually for rehabilitation and repair of steel-reinforced concrete infrastructure systems such as bridges and coastal structures due to deterioration caused by corrosion of steel. As a result, materials with better corrosion resistance and similar mechanical properties to steel are on demand. Glass Fiber Reinforced Polymer (GFRP) composite bars are corrosion-proof, provide high strength, are lightweight, and have superior chemical and electromagnetic properties when compared to ordinary steel reinforcement. GFRP bars however, degrade when exposed over long periods of time to the highly alkaline environments of concrete, among other degradation issues. This investigation focuses on the effect of high alkalinity on tensile and bond strength of several types of GFRP bars. Accelerated aging techniques were employed to explore the effects of GFRP characteristics (fiber volume fraction, matrix composition, bar diameter, and presence of protective coating) on their alkali resistance. Test results indicated that alkalinity has less impact on bars with lower fiber volume fractions and on bars treated with protective coating; mixed results were obtained in regard to matrix type and bar diameter comparisons. For the particular bond test specimens investigated in this project, accelerated aging did not change bond strength but altered the failure mechanism associated with bond failure of the specimens. |
