The effects of thermal creep of prestressing steel on post-tensioned concrete slabs in and after fire were investigated based on existing thermal creep model and calibrated parameters in this paper. A nonlinear finite element model was built up employing ABAQUS package, taking into account frictionless contact behaviour between prestressing steel tendons and surrounding concrete. The nonlinear material behaviour of concrete and prestressing steel at elevated temperatures was taken into account, where three material models for prestressing steel were adopted with or without considering thermal creep, and based on the model from EN 1992-1-2. The finite element model developed was verified against experimental results from the literature, showing that the model considering thermal creep was more accurate. Then the fire resistance period and responses of post-tensioned concrete slabs in and after fire were investigated based on the verified model. Ignoring thermal creep underestimated the fire resistance period but overestimated the residual tendon stresses. The model from EN 1992-1-2 achieved nearly the same effects as the model considering thermal creep in fire but might yield inaccurate evaluation of residual tendon stresses. The model considering thermal creep worked well under fire and in the post-fire conditions yielding reasonable predictions.
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机译：基于现有的热蠕变模型和标定参数，研究了预应力钢热蠕变对后张混凝土板火灾的影响。考虑到预应力钢索与周围混凝土之间的无摩擦接触行为，采用ABAQUS软件包建立了非线性有限元模型。考虑到混凝土和预应力钢在高温下的非线性材料性能，其中采用了三种考虑或不考虑热蠕变的预应力钢材料模型，并基于EN 1992-1-2中的模型。针对文献中的实验结果验证了所开发的有限元模型，表明考虑热蠕变的模型更为准确。然后，基于验证的模型，研究了火灾后和火灾后后张混凝土板的耐火期和响应。忽略热蠕变会低估耐火时间，但会高估残余的肌腱应力。 EN 1992-1-2中的模型获得了与考虑火灾中的热蠕变的模型几乎相同的效果，但可能会产生对残余腱应力的不准确评估。考虑到热蠕变的模型在火灾和后火条件下均能很好地发挥作用，从而得出合理的预测。
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