BFRP筋纤维混凝土梁抗弯性能试验研究

发布时间：2018-04-09 10:11

本文选题：BFRP筋　切入点：短切玄武岩纤维　出处：《西南科技大学》2017年硕士论文

【摘要】：BFRP(玄武岩纤维)筋是可以代替钢筋的一种新型抗腐蚀筋材,本文对已有的BFRP筋混凝土结构的文献调研发现,该结构在受弯时表现出挠度和裂缝较大的特点,且在文献调研中发现普通钢筋混凝土结构中掺入短切玄武岩纤维可以有效的改善混凝土的韧性和抗裂性能。因此,本文提出在BFRP筋混凝土结构中也掺入短切玄武岩纤维,以期能改善其原本较大的裂缝和挠度。根据文献调研的结果结合实际条件,本文重点研究了短切玄武岩纤维掺量和纵向BFRP筋配筋率对BFRP筋纤维混凝土梁抗弯性能的影响,对该种新型结构在实际工程中的应用有重要作用。本文主要工作可阐述为以下4个方面:(1)通过标准材性试验,得到了试验所用BFRP筋和纤维混凝土的基本力学性能,为BFRP筋纤维混凝土梁构件的抗弯性能分析提供数据支撑。(2)通过6种工况下的BFRP筋纤维混凝土梁抗弯试验后,得出了各试验梁的抗弯试验裂缝、挠度、承载力和破坏形式等试验现象。并结合试验现象对试验结果进行了分析,得出了 BFRP筋应变随荷载变化的规律,验证了该结构基本满足平截面假定。(3)通过分析不同玄武岩纤维掺量下BFRP筋纤维混凝土梁的抗弯性能。得出掺入短切玄武岩纤维后可有效提高BFRP筋纤维混凝土梁的开裂荷载,其提升的效果随纤维掺量的增加先增大后减小,本试验的各工况下,在短切玄武岩纤维掺量为0.4%时,开裂荷载提升幅度最大,达到60%。且掺入短切玄武岩纤维可有效延缓最大裂缝的开展,使得BFRP筋纤维混凝土梁的裂缝发展更为平均。(4)通过分析不同配筋率下的BFRP筋纤维混凝土梁的抗弯性能。得出BFRP筋梁的开裂荷载随配筋率变化不大;但BFRP筋梁的极限荷载随配筋率的减小而减小,且减小的幅度呈线性变化。BFRP筋梁的挠度随配筋率的增大而减小,但减小的幅度存在明显差异,当配筋率较小时,挠度随筋配筋率的增大减小幅度并不明显,平均在10%左右;当配筋率较大时,挠度随配筋率的增大减小幅度较大,平均在43%左右。
[Abstract]:BFRP (basalt fiber) reinforcement is a new type of corrosion-resistant steel bar which can replace steel bar. In this paper, it is found that the existing BFRP reinforced concrete structure shows the characteristics of large deflection and crack when it is subjected to bending.And in the literature investigation, it is found that adding short cut basalt fiber into the common reinforced concrete structure can effectively improve the toughness and crack resistance of concrete.Therefore, in this paper, the short cut basalt fiber is added to the concrete structure of BFRP bar in order to improve the original crack and deflection.Based on the results of literature investigation and practical conditions, the effects of the content of short cut basalt fiber and the ratio of longitudinal BFRP reinforcement on the flexural behavior of BFRP reinforced concrete beams are studied in this paper.It plays an important role in the application of the new structure in practical engineering.The main work of this paper can be described as follows: (1) the basic mechanical properties of BFRP tendons and fiber reinforced concrete used in the test are obtained through the standard material test.This paper provides data support for the analysis of flexural behavior of BFRP reinforced fiber reinforced concrete beams. After the flexural tests of BFRP reinforced fiber reinforced concrete beams under six conditions, the bending test cracks and deflections of each test beam are obtained.Test phenomena such as bearing capacity and failure form.Combined with the experimental phenomenon, the experimental results are analyzed, and the law of strain variation of BFRP bars with load is obtained.It is verified that the structure basically meets the assumption of plane section. The flexural behavior of BFRP reinforced fiber reinforced concrete beams with different basalt fiber content is analyzed.It is concluded that the crack load of BFRP reinforced concrete beams can be effectively increased by adding short cut basalt fibers, and the lifting effect increases first and then decreases with the increase of fiber content. In each working condition of this experiment, when the content of short cut basalt fibers is 0.4,The range of cracking load lifting is the largest, reaching 60%.Adding short cut basalt fiber can delay the development of maximum crack and make the crack development of BFRP reinforced concrete beam more average. 4) the flexural behavior of BFRP reinforced concrete beam with different reinforcement ratio is analyzed.It is concluded that the crack load of BFRP reinforced beam varies little with the reinforcement ratio, but the ultimate load of BFRP beam decreases with the decrease of reinforcement ratio, and the amplitude of the decrease is linear. The deflection of BFRP-reinforced beam decreases with the increase of reinforcement ratio.The average is about 43%.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU37

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