火灾后陶粒泡沫混凝土夹层复合剪力墙轴压性能试验研究

【作者】 苏静；

【导师】 刘春阳； 王文勋；

【作者基本信息】 山东建筑大学 ， 土木水利硕士（专业学位）， 2024， 硕士

【摘要】 目前,剪力墙作为高层建筑中常用的抗侧力构件被广泛应用,陶粒泡沫混凝土是一种新型建筑材料,具有轻质、隔热、环保等特性,陶粒与泡沫混凝土两者相结合的无机建筑材料性能上既优于陶粒混凝土的性能,也优于泡沫混凝土的性能。与普通混凝土相比,陶粒泡沫混凝土具有轻质高强、保温性能好、耐火性好、施工适应性强的优点,与普通泡沫混凝土相比,陶粒泡沫混凝土有效改善了泡沫混凝土易收缩开裂的缺点。将其应用到结构中,在减轻建筑物自重的同时,还可以作为建筑墙体保温材料,起到保温隔热的作用。本文提出一种新型轻量化陶粒泡沫混凝土夹层复合剪力墙,包括普通混凝土两侧面层和陶粒泡沫混凝土中间保温夹芯层,并通过拉结筋,钢筋桁架筋将三层连成一体,使三层混凝土能够有效的协同工作。本文所研究的新型轻质陶粒泡沫混凝土夹层复合剪力墙在灾后的工程应用中仍然充当剪力墙使用。目前已有的研究基本上都是火灾中的试验研究,对剪力墙结构的火灾后试验研究很少,对此种新型墙体的火灾后性能研究就更少了。本文主要进行了如下研究工作:(1)本文以墙体面层厚度、中间夹芯层厚度、拉结筋形式、约束构件有无为主要设计参数,设计并制作了5片夹层复合剪力墙。对5片陶粒泡沫夹层复合剪力墙进行了ISO-834标准火灾试验和受火后的轴压性能试验,并对陶粒泡沫混凝土夹层复合剪力墙火灾下的温度场分布特征、火灾后表观现象、火灾后轴压破坏特征、承载性能以及应变发展变化规律进行了研究。分析了面层厚度、中间夹心层厚度、拉结筋形式、约束构件有无对火灾后陶粒泡沫夹层复合剪力墙轴压性能的影响。(2)本文采用三台阶模型法、改进三台阶模型法、二台阶模型法以及优化截面法对火灾后陶粒泡沫混凝土夹层复合剪力墙的轴压承载力进行计算,并对不同计算方法得到的承载力与试验值进行了对比。结果表明,以上四种理论计算方法计算值与试验值误差均小于20%,因此以上几种方法均适用于火灾后陶粒泡沫混凝土夹层复合剪力墙轴压承载力的计算。(3)利用有限元模拟软件ABAQUS建立陶粒泡沫混凝土夹层复合剪力墙温度场模型和火灾后陶粒泡沫混凝土夹层复合剪力墙力学模型,模拟其温度场分布和火灾后轴压加载的力学行为,将数值模拟结果与试验值进行对比分析,在验证有限元模型合理可靠的基础上,进一步研究了混凝土强度、受火时间、面层厚度、高宽比、配筋率对火灾后墙体受压性能的影响。(4)本文采用有限元模拟软件ABAQUS模拟火灾后陶粒泡沫混凝土夹层复合剪力墙时,变换影响参数,获得了50组试件的数据,将50组数据导入MATLAB分别建立了BP网络预测模型、遗传算法优化的-BP神经网络模型、麻雀算法优化的-BP神经网络模型、进行了多因素影响下的陶粒泡沫混凝土复合夹层剪力墙的配筋设计,与有限元软件得到的50组数据的结果对比,发现基于麻雀算法优化的BP神经网络模型预测的剪力墙的承载力误差更小,为研究复合剪力墙轴压承载力提供了新方法。进一步采用麻雀算法优化的BP神经网络模型预测陶粒泡沫混凝土复合夹层剪力墙的配筋设计。更多还原

【Abstract】 At present,shear walls are widely used as lateral force resistance components in high-rise buildings.Ceramide foamed concrete is a new type of building material which integrates light weight,heat insulation and heat preservation.The performance of inorganic building material combining ceramisite and foamed concrete is better than that of ceramisite concrete and foamed concrete.Compared with ordinary concrete,ceramsite foamed concrete has the advantages of heat preservation,sound insulation,light weight,environmental protection,economy,waste benefit and durability.Compared with ordinary foamed concrete,ceramsite foamed concrete effectively overcomes the shortcomings of foam concrete shrinkage and cracking.Applied to the structure,it can not only reduce the weight of the building itself,but also be used as a building wall insulation material.In this thesis,a new type of lightweight ceramsite foamed concrete sandwich composite shear wall is proposed,which consists of two sides of ordinary concrete and the middle insulation sandwich layer of ceramsite foamed concrete.The three layers are connected together through the reinforcement and steel truss bars,so that the three layers of concrete can work together effectively.The new lightweight ceramide foam concrete sandwich composite shear wall studied in this thesis is still used as a shear wall in post-disaster engineering applications.At present,the existing research is basically the test research in the fire,the post-fire test research on the shear wall structure is very few,and the post-fire performance research of this new type of wall is even less.The main research work in this thesis is as follows:(1)In this thesis,the thickness of wall surface layer,the thickness of intermediate sandwich layer,the form of tension reinforcement and the presence or absence of constraint members are the main design parameters,and five sandwich composite shear walls are designed and produced.The ISO-834 standard fire test and axial compression test of 5 pieces of ceramide foam sandwich composite shear wall were carried out,and the temperature field distribution characteristics,apparent phenomena after fire,axial compression failure characteristics after fire,bearing performance and strain development law of ceramide foam concrete sandwich composite shear wall were studied.The effects of the thickness of the surface layer,the thickness of the middle sandwich layer,the form of tension reinforcement and the presence or absence of restraint members on the axial compressive properties of the composite shear wall after the fire are analyzed.(2)In this thesis,the three-step model method,the improved three-step model method,the two-step model method and the optimized section method are used to calculate the axial compressive capacity of the composite shear wall with ceramsite foam concrete sandwich after the fire,and the bearing capacity obtained by different calculation methods is compared with the test value.The results show that the error between the calculated values and the experimental values of the above four theoretical calculation methods is less than 20%,so the above methods are suitable for the calculation of the axial compressive capacity of the composite shear wall with ceramsite foam concrete sandwich after fire.(3)The finite element simulation software ABAQUS was used to establish the temperature field model of ceramsite foamed concrete sandwich composite shear wall and the mechanical model of ceramsite foamed concrete sandwich composite shear wall after fire to simulate the distribution of its temperature field and the mechanical behavior of axial compressive loading after fire.The numerical simulation results were compared and analyzed with the test values.On the basis of verifying the rationality and reliability of the finite element model,The influences of concrete strength,fire time,surface thickness,height-width ratio and reinforcement ratio on compressive performance of wall after fire are further studied.(4)In this thesis,the finite element simulation software ABAQUS was used to simulate the composite shear wall with ceramite foam concrete sandwich after fire,and the influence parameters were changed to obtain the data of 50 groups of specimens.After 50 sets of data were imported into MATLAB,the BP network prediction model,the-BP neural network model optimized by genetic algorithm,and the-BP neural network model optimized by Sparrow algorithm were established respectively.The reinforcement design of the ceramic foamed concrete composite sandwich shear wall under the influence of multiple factors was carried out.The results were compared with the 50 sets of data obtained by the finite element software.It is found that the error of shear wall bearing capacity predicted by BP neural network model optimized by Sparrow algorithm is smaller,which provides a new method for studying the axial compressive capacity of composite shear wall.Further,the BP neural network model optimized by Sparrow algorithm is used to predict the reinforcement design of ceramsite foamed concrete composite sandwich shear wall.更多还原