钢纤维水泥砂浆钢筋网外包RC梁抗剪试验研究

发布时间：2018-10-22 19:35

【摘要】：钢纤维砂浆钢筋网加固方法是一种新型混凝土结构加固补强技术,在传统的水泥砂浆中掺入一定量的钢纤维,钢纤维均匀分布在水泥砂浆中,共同消耗外部能量,发挥钢纤维抗拉强度高的特点,限制裂缝产生于发展,从而提高水泥砂浆抗裂性能。通过凿毛、刷界面剂等界面处理,再外包钢纤维砂浆钢筋网薄层,植入剪切销钉,保证加固层与原构件共同受力,以提高构件承载力、延性、耐久性。该加固方法基本不增加构件几何尺寸和重量,试用性较强,易于推广。目前国内少数学者对纤维砂浆钢筋网薄层加固RC梁抗弯性能进行了一系列试验与理论研究,抗剪研究较少,对伸臂梁抗剪性能研究更少。因此本文通过2根对比RC伸臂梁和2根采用钢纤维砂浆钢筋网加固的RC伸臂梁剪切破坏试验,在试验结果基础之上,分析对比梁和试验梁在不同剪跨比下的剪切破坏形态、开裂荷载、极限荷载、裂缝、挠度、应变的变化规律。试验表明,该加固方法能限制裂缝的产生于发展,提高RC梁开裂荷载、延性、刚度以及抗剪极限承载力。依据试验结果,分别采用塑性分析方法和桁架—拱模型,提出RC伸臂梁采用钢纤维砂浆钢筋网加固的抗剪极限承载力计算公式。通过比较,塑性分析法与桁架—拱模型计算结果有一定的差异,塑性法结果与试验结果更吻合,具有一定的理论与实践意义。最后采用ABAQUS有限元分析软件进行非线性有限元分析,将试验结果与有限元分析结果对比,进一步分析和验证了钢纤维砂浆钢筋网加固方法的有效性与试用性。可为实际工程提供借鉴与参考。
[Abstract]:The reinforcement method of steel fiber mortar reinforced mesh is a new reinforcement technique for concrete structure. A certain amount of steel fiber is added to the traditional cement mortar, and the steel fiber distributes uniformly in the cement mortar, which consumes the external energy together. In order to improve the crack resistance of cement mortar, the characteristics of high tensile strength of steel fiber are brought into play and cracks are restricted from the development of cement mortar. In order to improve the bearing capacity, ductility and durability of the members, the interfacial treatment such as hair-chiseling, brushing interface agent and so on, the steel fiber mortar reinforced steel mesh thin layer and shear pin were inserted to ensure the joint force between the strengthened layer and the original member in order to improve the bearing capacity, ductility and durability of the members. The reinforcement method has no increase in geometric size and weight, and is easy to be popularized. At present, a few domestic scholars have carried out a series of experimental and theoretical studies on the flexural behavior of RC beams strengthened with fiber mortar steel mesh thin layer. There are few researches on shear resistance of RC beams, and even less on the shearing properties of cantilever beams. Therefore, the shear failure tests of two contrast RC cantilever beams and two RC cantilever beams strengthened with steel fiber reinforced mortar mesh are carried out in this paper. Based on the experimental results, the shear failure patterns of the contrast beams and the test beams under different shear span ratios are analyzed. Crack load, limit load, crack, deflection, strain change law. The experimental results show that this method can limit the occurrence of cracks and improve the cracking load ductility stiffness and ultimate shear capacity of RC beams. Based on the test results, the plastic analysis method and truss-arch model are used to calculate the shear ultimate bearing capacity of RC cantilever beams strengthened with steel fiber mortar steel mesh. By comparison, the results of plastic analysis method and truss-arch model are different to some extent, and the results of plastic analysis are more consistent with the experimental results, which is of theoretical and practical significance. Finally, the nonlinear finite element analysis is carried out by using the ABAQUS finite element analysis software. The experimental results are compared with the results of the finite element analysis, and the effectiveness and the trial performance of the steel fiber reinforced mortar reinforcement method are further analyzed and verified. It can provide reference and reference for practical engineering.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU375.1

【相似文献】