混杂纤维再生混凝土梁抗裂性能试验研究

发布时间：2018-05-03 00:43

本文选题：再生粗骨料 + 混杂纤维混凝土　；参考：《延边大学》2017年硕士论文

【摘要】：随着农村城镇化和城市建设的发展,大量旧建筑物被拆除重建,继而产生了大量的建筑垃圾,长久以来给城市的发展造成了严重的负担,为了合理地资源回收再利用,降低环境污染。目前,国内外学者们将粉煤灰、废弃混凝土等再利用于混凝土搅拌中。但使用这些循环资源的混凝土由于强度降低、抗裂性较差,其实际用用受到限制。据研究资料表明:纤维可以有效的弥补再生混凝土本身的孔隙率大、密实度低等缺陷。因此,为了提高再生混凝土梁的抗裂性能,本文通过改变纤维的不同种类、不同长度、不同掺入方式等方法,分析了再生混凝土的基本力学性能和构件梁的抗裂性能,具体试验结果如下:(1)通过对单掺及混掺不同种类、不同长度的纤维混凝土的力学性能试验研究发现,混凝土中掺入纤维对抗压强度影响不大,但可明显提高劈裂抗拉强度。通过比较各试验组拉压比值可得出,试验组G12P35组的抗裂性能比较良好。(2)通过比较不同种类单掺及混掺纤维再生混凝土梁的抗裂性能的试验研究得出,掺入纤维的再生混凝土梁与普通混凝土梁具有相似的破坏过程,都经历了弹性、开裂、屈服、极限四个阶段。加入纤维不会提高构件梁的开裂荷载,但一定程度上提高了构件的极限荷载。通过分析比较不同梁构件的荷载-裂缝宽度、荷载-跨中挠度及裂缝数量研究发现,混掺纤维对于提高再生混凝土梁的抗裂性能要好于单掺纤维试验组。(3)根据本次试验结果,分析《混凝土结构设计规范》中的最大裂缝宽度及挠度公式,引入最大裂缝宽度的影响系数K及最大挠度的影响系数N,分别进行计算推导。(4)运用ANSYS模拟软件对混杂纤维再生混凝土梁做有限元分析,将模拟数据与计算数值进行对比分析,得出模拟值与计算值基本吻合,说明ANSYS有限元软件对混凝土构件的性能分析是适用的。
[Abstract]:With the development of rural urbanization and urban construction, a large number of old buildings have been demolished and rebuilt, resulting in a large amount of construction waste, which has caused a serious burden to the development of the city for a long time. Reduce environmental pollution. At present, scholars at home and abroad will fly ash, waste concrete and other reuse in concrete mixing. However, the concrete using these circulating resources is limited in practical use because of its low strength and poor crack resistance. According to the research data, the fiber can effectively compensate the defects such as high porosity and low compactness of recycled concrete. Therefore, in order to improve the crack resistance of recycled concrete beams, this paper analyzes the basic mechanical properties of recycled concrete and the crack resistance of member beams by changing the different types of fibers, different lengths and different ways of mixing. The concrete test results are as follows: (1) by studying the mechanical properties of fiber reinforced concrete with different types and different lengths, it is found that the addition of fiber in concrete has little effect on the compressive strength, but it can obviously improve the splitting tensile strength. By comparing the tensile and compression ratios of each test group, it can be concluded that the crack resistance of the G12P35 group in the test group is better than that of the test group. (2) by comparing the crack resistance of different kinds of recycled concrete beams with single and mixed fibers, it is concluded that the crack resistance of the test group is better than that of the G12P35 group. The recycled concrete beams mixed with fiber have similar failure process with ordinary concrete beams, and they all go through four stages: elasticity, cracking, yield and limit. Adding fiber does not increase the cracking load of the member beam, but to some extent increases the ultimate load of the member. By analyzing and comparing the load-crack width, load-span deflection and the number of cracks of different beam members, it is found that the crack resistance of recycled concrete beams with mixed fiber is better than that of single fiber reinforced concrete beams. The formula of maximum crack width and deflection in the Code for Design of concrete structures is analyzed. The influence coefficient K of maximum crack width and the influence coefficient of maximum deflection N are introduced to calculate and deduce respectively. The finite element analysis of hybrid fiber regenerated concrete beams is done by using ANSYS simulation software, and the simulation data are compared with the calculated values. The simulation results are in good agreement with the calculated values, which shows that the ANSYS finite element software is applicable to the performance analysis of concrete members.
【学位授予单位】：延边大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU37

【参考文献】