Damage evaluation of precast concrete beams post-tensioned with unbonded tendons using fiber based model analysis

Abstract

In order to fully take advantage of low damage characteristics of unbonded prestressed precast concrete structures, it is important to develop a numerical model to simulate their structural performance with high accuracy. This study focuses on developing a simple fiber based model and simulating damage of post-tensioned precast concrete members for function continuity and quick recovery. First, four limit states were defined for unbonded prestressed concrete beams based on the 2015 AIJ prestressed concrete guidelines and applied to test results of six unbonded prestressed precast concrete beams. Then, a fiber-based model was developed to simulate the test results in term of load - displacement relation, strain and stress conditions of concrete, mild reinforcement and tendons. It was confirmed that the proposed model is able to simulate the test results in such good accuracy from stress and deformation aspects that appearance of limit states also agreed well with experimental data.