碳纤维约束高强混凝土轴心抗压性能试验研究

发布时间：2018-06-15 05:30

本文选题：碳纤维增强复合材料 + 约束混凝土　；参考：《河北联合大学》2014年硕士论文

【摘要】：采用纤维增强复合材料（FRP）包裹约束混凝土，能够使混凝土在受到轴向压力时处于三相受压应力状态，从而能够改善混凝土材料构件承受轴向压力时的承载能力与变形性能。混凝土材料作为建筑工程当中最常用的抗压材料之一，其轴压力学性能密切影响着结构轴压构件与抗弯构件的力学性能。通过环向FRP片材包裹加固，改善混凝土的抗压性能，对改善混凝土构件及结构整体的力学性能有很重要的意义。目前针对FRP约束混凝土轴心抗压能力的研究多针对强度等级在C40以下的混凝土进行，对高强度等级的FRP约束混凝土研究较少。混凝土强度等级为一个约束混凝土抗压力学性能较为主要的影响因素，高强度等级混凝土在经FRP约束时的力学性能有重要的研究价值。进行了混凝土强度等级在C40~C60区间的碳纤维增强复合材料（CFRP）环向包裹加固圆柱体轴压对比试验，试验每个强度等级制作素混凝土试件与CFRP约束试件各一组，每组试件3个，试验结果取平均值，以研究混凝土强度等级对CFRP约束混凝土轴压力学性能的影响。同时C40、C50强度等级制作包裹1~3层CFRP的试件，研究CFRP包裹层数对约束混凝土轴压力学性能的影响，由试验结果可以看出外包CFRP对混凝土起到了理想的约束作用，改善了混凝土的抗压力学性能。通过对试验数据回归分析，提出了CFRP约束高强混凝土圆柱的轴压极限抗压强度与峰值应变的计算模型，并提出了相应的应力—应变关系模型。利用能量法对CFRP约束混凝土轴压的试验结果进行了破坏能量密度的计算，通过能量角度分析了CFRP约束对混凝土轴压能力的改善作用。并通过搜集计算已有FRP约束混凝土轴压试验的破坏能量密度，研究了不同因素对FRP约束混凝土柱轴压破坏能量密度的影响。
[Abstract]:Using fiber reinforced composite material (FRP) to wrap confined concrete can make the concrete under axial pressure in the state of three-phase compressive stress, thus can improve the bearing capacity and deformation performance of concrete members under axial pressure. As one of the most commonly used compressive materials in building engineering, the axial compression mechanical properties of concrete materials affect the mechanical properties of structural axial compression members and flexural members. It is very important to improve the compressive performance of concrete and improve the mechanical properties of concrete members and structures by enclosing and strengthening with circumferential FRP sheets. At present, the research on the axial compressive capacity of FRP confined concrete is mostly focused on concrete with strength grade below C40, but less on FRP confined concrete with high strength grade. The strength grade of concrete is one of the main factors affecting the compressive mechanical properties of confined concrete, and the mechanical properties of high strength grade concrete under FRP confinement are of great value. The axial compression tests of CFRP- reinforced carbon fiber reinforced composites (CFRPs) with concrete strength grade in C40 / C60 region are carried out. The results show that each strength grade makes a group of plain concrete specimens and CFRP confined specimens, with 3 specimens per group. In order to study the influence of concrete strength grade on the axial compressive mechanical properties of CFRP confined concrete, the average test results are taken. At the same time, the strength grade of C40 / C50 is used to make the specimen wrapped with 1 / 3 CFRP. The effect of the number of CFRP enclosing layers on the mechanical properties of confined concrete under axial compression is studied. From the experimental results, it can be seen that the wrapped CFRP acts as an ideal constraint on concrete. The compressive mechanical properties of concrete are improved. By regression analysis of test data, a calculation model of axial compression ultimate compressive strength and peak strain of CFRP confined high strength concrete cylinder is proposed, and the corresponding stress-strain relationship model is proposed. The failure energy density of CFRP confined concrete under axial compression is calculated by energy method. The effect of CFRP confinement on the axial compression capacity of concrete is analyzed by energy angle. Through collecting and calculating the failure energy density of FRP-confined concrete under axial compression test, the influence of different factors on the failure energy density of FRP-confined concrete column is studied.
【学位授予单位】：河北联合大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU37

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