01763567

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Prefabricated post-tensioned pre-stress concrete (PC) T-girder is one of common structural forms for bridge superstructure since it has better quality control, higher construction speed, and lower downtime to the transportation system. However, vertical cracks are frequently observed at the web of girder ends after prestress is applied, which could impose an adverse effect on the durability of girders when exposed to aggressive environment. In this paper, mechanism of this cracking pattern and corresponding countermeasure were investigated by numerical study as well as practical engineering application. To begin with, a nonlinear finite element model was developed to simulate a typical PC T-girder in ABAQUS. Details of the numerical modeling techniques are described. The model was loaded based on the sequence of post-tensioning. It was found that the vertical crack pattern is caused by the large friction resistance and bond strength at the contact surface between the girder and supporting steel pedestal at the girder ends. In addition, a practical method was proposed to control this crack pattern by introducing an isolation cushion made of thin wood pieces to the bottom of girder ends. The reliability of this method was verified by numerical analysis and observations from engineering practice. Therefore, it can be used to control vertical cracks at ends of prefabricated post-tensioned PC bridge T-girders during construction.

This paper was sponsored by TRB committee AKB30 Standing Committee on Concrete Bridges.

TRBAM-21-01916

English

14p

2021

Transportation Research Board 100th Annual Meeting

Web

Figures; References; Tables

Bridge construction; Cracking; Girder bridges; Girders; Methodology; Posttensioning; Prefabricated structures; Prestressed concrete

Bridges and other structures; Construction; Highways

Transportation Research Board Annual Meeting 2021 Paper #TRBAM-21-01916

TRIS, TRB, ATRI

Dec 23 2020 11:06AM