Long-term bond degradation of GFRP-RC beams in the complex alkaline environment for eight years.

• The long-term bond durability of GFRP-RC beam structure is investigated; • The mBPE model was modified to consider the splitting of concrete cover; • The effect of working crack on structural bond performance is re recognized; • The long-term bond behavior prediction model of GFRP-RC beam was proposed. This paper investigates the long-term bond-slip behavior of GFRP (glass fiber reinforced polymer)-RC (reinforced concrete) beams. The specimens used in the bond test have been exposed to alkaline accelerated corrosion solution for eight years. In order to more accurately explore the long-term degradation law of the GFRP-RC beam, the factors of sustained load, pre-crack, and specimen form are also considered in this test. The experimental results show that the long-term degradation efficiency of specimens with pre-cracks increases significantly. The interfacial fracture energy and maximum bond strength at fracture failure are reduced by 16% and 23%, respectively. Although the overall bond performance of GFRP-RC beams will deteriorate with service time, the structure usually enters the slow degradation stage. However, the pre-cracks inhibit the arrival of this stage so that the structure will suffer more damage. In order to more intuitively evaluate the safety level of the residual bond performance of the structure in the current state, the long-term degradation prediction model of the GFRP-RC beam is established. [ABSTRACT FROM AUTHOR]