Evaluation of end-zone detailing of pre-tensioned concrete girders

Abstract

This paper presents an evaluation of existing design models for the reinforcement detailing of the anchorage zone of pre-tensioned concrete girders. Different design models available in the literature are evaluated for a single pre-tensioned element fitted with an end-block and the resulting reinforcement lay-outs are modelled using a two-stage numerical approach. Within this approach, both the transfer of the prestress force from the pretensioning strands to the surrounding concrete and the strain field in the anchorage zone are consecutively accounted for. Non-linear material behaviour is applied to correctly model the possible stress redistribution after cracking has occurred. The different end-zone reinforcement lay-outs are evaluated by monitoring the total vertical strains throughout the reinforcement of the numerical model. Additionally, a parametric study is performed to further investigate the influence of different end-zone reinforcement lay-outs and to evaluate the efficiency of varying geometric placement of the reinforcement bars. Lastly, guidelines for efficient end-zone reinforcement detailing of pre-tensioned girders are suggested.