Evaluation Method for Ultimate Flexural State of Prestressed Precast Reinforced Concrete Beam–Column Connection with Debonded Partial Tendon

Abstract

In this paper, a prestressed precast reinforced concrete (PC) beam–column connection incorporating posttensioned debonded partial tendons is introduced for PC frame structure. Compared with the conventional cast-in-place frames and many previously proposed connections for PC frames, this connection has the advantage of self-centering and low damage in strong earthquakes. In addition, the debonded partial tendons can reduce the posttensioning demand and further reduce site labor during construction and repair. In order to establish a performance evaluation method for the ultimate flexural limit of the proposed PC connection, an analytical model was developed to accurately reflect the deformation compatibility and force equilibrium conditions of the PC beam and column members, as well as the debonded partial tendons. Based on this, iterative and direct evaluation methods for the strength and deformation of the PC connections, as well as the strains of the debonded tendons, were developed. The proposed methods were verified by cyclic loading test on the beam–column connection subassemblages. It is concluded that the proposed method is sufficiently accurate and simple to be applied in engineering design, and is helpful to guarantee the self-centering and low-damage characteristics of the proposed connection against a strong earthquake.