无粘结预应力混凝土连续板边跨受火试验研究

Experimental investigation of the behavior of continuous slabs of unbonded prestressed concrete with the end span under fire

本文对3块无粘结预应力混凝土连续板在边跨受火下的火灾行为进行了试验研究。试验中考虑了负弯矩筋长度和预应力度两个主要因素。得出了板的温度场分布、板的变形及支反力的变化情况。并得出了负弯矩筋长度、预应力度对无粘结预应力混凝土连续板的影响。试验结果表明负弯矩筋的长度对板的破坏形式影响明显,而预应力度的影响则不明显。为今后无粘结预应力混凝土结构的火灾行为研究提供依据。

In this paper,the behavior of continuous slabs of unbonded prestressed concrete with the end span under fire were investigated. Length of negative moment reinforcement and level of prestress were the main factors of the specimens. From the test results, the regularities of temperature field, deformations and reactions of slabs were obtained. The effect of different lengths of negative moment reinforcement and levels of prestress on the behavior of the slabs were also acquired. The results of the experiment showed that the failure mode of slab was influenced significantly by the length of negative moment reinforcement ,but it was not obvious by the influence of level of prestress. Conclusions of this paper may provide a basis for further research on fire behavior of prestressed concrete structures with unbonded tendon.