Experimental Study on Long-Term Performance of Postinstalled Reinforcing Bars

Postinstalled reinforcing bars play a crucial role in maintaining, extending the service life, and enhancing the seismic capacity of existing concrete structures. The displacement-time distribution under sustained loading for 90 days was established through long-term performance testing. As a result, a long-term slip calculation formula was derived, and a 50-year slip prediction method for postinstalled reinforcing bars was developed. Additionally, a comparative analysis of the pullout damage between postinstalled reinforcing bars and benchmark specimens after long-term loading was conducted to evaluate embedment performance, including stiffness degradation and residual capacity loss due to creep. A comprehensive methodology for the long-term performance inspection and testing of postinstalled reinforcing bar systems is also proposed for engineering evaluations.