先张法预应力空心板火损评定方法及处治对策

Fire-damage Evaluation Method of Pretensioned Hollow Plates and Countermeasures

火灾对先张法预应力空心板的安全性、耐久性存在非常不利的影响,详细阐述了火灾事故的处置思路和具体方法。研究提出综合采用颜色判别法、损伤程度判别法以及空心板内部温度场有限元分析法,以便更准确地判别火灾后结构的内部损伤。研究结果表明,火灾高温灼烧后混凝土强度严重下降,结构工作性能降低甚至丧失。通过对火损后结构表观状况和各类重要指标劣化的检测、火灾时结构表面温度推算、结构内部温度场模拟分析,研究得出判别内部损伤深度情况的方法,对损伤程度不同的板梁分别提出了保留利用、加固或拆除等相应处置措施。

There is a very negative impact of fire on safety and durability of the pretensioned hollow plates.Treatment ideas and specific methods of fire accidents were described in detail.A combination of color discriminance,damage degree discriminance and finite element analysis of internal temperature field discriminance was proposed to discriminate the internal damage of structures after fire more accurately.The results show that there is a serious decline in the strength of concrete after fire,and structural performance is reduced or even lost.Through detection of apparent situation and deterioration of some important indexes after fire,reckoning of surface temperature and simulation of internal temperature during fire,the way of distinguishing the depth of internal damages was obtained.For the plate girders with different damage degrees,the countermeasures of preserving,strengthening or demolishing method were proposed respectively.