GHPFRCC新型框架结构抗火性能数值模拟研究

Study on the Fire Resistance Performance of GHPFRCC New Frame Structure

绿色高性能纤维增强水泥基复合材料(Green High Performance Fiber Reinforced Cementitions Composites,GHPFRCC)是通过大掺量工业废料粉煤灰取代水泥,并加入聚乙烯醇纤维等材料制备而成一种复合材料,具有绿色环保、力学性能优异的特点。为了研究高温作用下GHPFRCC框架结构温度场分布和结构变形的特点,对三榀“田”字形GHPFRCC框架进行耐火试验,并通过ABAQUS软件对框架受火方式、核心区配箍率、核心区保护层是否浇筑GHPFRCC材料三种参数进行模拟分析。结果表明,GHPFRCC材料具有较大比热容以及较低热传递系数,在火灾下GHPFRCC材料浇筑区域内部温度比普通混凝土偏低明显,材料耐火性能良好;随着受火腔数的增加,框架的温度升高,轴向位移有所增加;低轴压比下核心区配箍率对GHPFRCC框架温度场分布和轴向变形影响较小;使用GHPFRCC浇筑核心区保护层能够提高结构的耐火性能。

Green high performance fiber reinforced cementitions composites(GHPFRCC)is mainly produced by using industrial waste fly ash to replace cement partly and adding polyvinyl alcohol fibers in cement matrix,which is friendly to environmental and has excellent performance in mechanical property.In order to study the characteristics of temperature field distribution and structural deformation of GHPFRCC frame structures under elevated temperature,three new shaped frame are tested and the finite element analysis software ABAQUS is used to simulate and analyze the performance of GHPFRCC frames under different working conditions:the number of fire chambers,the hoop ratio of the core area,and the effect of pouring of GHPFRCC material in the core area protective layer.The results show that:GHPFRCC material has a larger specific heat capacity and a lower heat transfer coefficient,and the internal temperature under fire is significantly lower than the ordinary concrete pouring area,which helps to enhance the fire resistance;as the number of refractory cavities increases,the temperature is higher and axial displacement of the frame would increase;under the low axial compression ratio,the coupling rate of the core area has little effect on the temperature field and axial deformation of the GHPFRCC frame;plus,we can conclude from the research that using GHPFRCC to pour the protective layer of the core area can improve the fire resistance of the structure and save engineering costs,which is helpful in engineering practice.