Long-time durability of GFRP bars in the alkaline concrete environment for eight years

Abstract The long-term durability of glass fiber reinforced polymer (GFRP) bars under different conditioning environments is investigated in this paper. A batch of GFRP bars exposed to alkaline accelerated corrosion concrete environment for 8 years is studied. The long-term tensile strength degradation law/micro deterioration mechanism are analyzed, and the tensile strength prediction model of GFRP bars is established. By comparing the estimated results with the long-term experimental data, it is found that the prediction model fits the first stage degradation data of GFRP bars well and has high accuracy. However, the long-term durability of GFRP bars is significantly underestimated based on the prediction results in the second stage, so an improved long-term tensile strength prediction model is proposed. Finally, the 8-year residual tensile strength of GFRP bars is evaluated according to three current codes.