活性粉末混凝土(RPC)槽形梁模型破坏试验研究

Study on Failure Experiment of RPC Trough Beam Model

活性粉末混凝土 (RPC)具有高强、高耐久性以及高延展性等特点 ,因此 ,RPC在桥梁中有很好的应用前景。但是当前对RPC桥梁的设计研究很少 ,笔者根据自行研制的RPC ,设计了预应力拼装结构的槽形梁模型 ;并进行了RPC槽形梁模型的破坏试验研究 ,以验证槽形梁模型的承载力及发现设计上存在的问题。通过对模型拼装、预应力张拉及模型加载的试验现象的介绍和对试验结果的分析可知 ,破坏时主梁底部的拉应力远没有达到RPC的抗拉极限强度 ,而主梁腹板和下翼缘连接处的局部承载力不足才是主梁破坏的真正原因。最后 ,在总结裂缝发展和模型破坏的原因的基础上 ,对进一步的模型设计提出了修改意见。

Reactive powder concrete (RPC) has ultra-high strength, high durability and high ductility, which shows good prospect in bridge building. However, research work is rarely done in its design. An assembled pre-stressed RPC trough beam model is designed with the self-developed RPC and an experimental study on RPC trough beam model is investigated to validate the bearing capacity and find the imperfection of the model. Through the introduction and analysis of the experimental phenomena on the model assembling, pre-stressing and loading process, it is found that the bottom tensile stress of the I-beam is very small and the reason for the failure of the model is the insufficient local bearing capacity between the web and the bottom flange. Based on the analysis on causes of crack distribution and model failure, suggestions for perfecting the model design are presented.