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在ISO 834标准升温条件下,进行了8个预制混凝土叠合楼板足尺试件的耐火性能试验,考察钢筋类别、板底是否涂抹水泥砂浆粉刷层以及简支或连续等因素对叠合楼板耐火极限的影响。试验结果表明:在ISO 834标准火灾下,以跨中挠度变化率作为叠合楼板达到耐火极限的判别标准更为合理;所有试件最终均发生跨中区域横向受拉裂缝引起的弯曲破坏,破坏时各试件的跨中挠度较大,延性较好;预应力试件耐火极限小于常温下等强配筋的非预应力试件;板底涂抹粉刷层后,抑制了板内受力钢筋温度的升高,耐火极限明显提高;连续试件约束了悬挑端上翘,降低了试件的荷载水平,耐火极限提高幅度最大。采用有限元分析软件ABAQUS对试验叠合楼板进行了火灾反应分析,有限元分析结果与试验结果吻合良好。试验和有限元结果表明:连续叠合楼板能够满足楼板耐火等级为一级的实际工程需要。
In the ISO 834 standard temperature conditions, the 8 prefabricated concrete floor slab full-scale specimens of fire resistance test to examine the type of reinforcement, the bottom is coated with cement mortar brushing and simple support or continuous and other factors on the fire-resistant laminate floor The impact of the limit. The test results show that under ISO 834 standard fire, it is more reasonable to use the rate of change of mid-span deflection as the criterion to reach the fire resistance limit of the laminated floor. All the specimens eventually undergo bending damage caused by transverse tension cracks in the mid- The mid-span deflection of each specimen is larger and the ductility is better; the pre-stressing specimens have lower fire resistance than non-prestressed specimens with equal strength reinforcement at room temperature; , And the fire resistance limit increased obviously. The continuous specimen restrained the cantilevered end upturned, which reduced the load level of the specimen and the maximum fire resistance was increased. The fire response analysis of the test laminated floor was carried out by the finite element analysis software ABAQUS. The results of the finite element analysis agree well with the experimental results. The experimental results and the finite element results show that the continuous laminated floor can meet the practical engineering needs of the fireproof level of the floor.