混杂纤维混凝土基本力学性能与板件的抗爆性能研究

发布时间：2017-12-27 12:03

本文关键词：混杂纤维混凝土基本力学性能与板件的抗爆性能研究　出处：《广西大学》2016年硕士论文　论文类型：学位论文

【摘要】：混凝土作为一种多相材料,在受力前就存在着微裂缝,而在混凝土中添加纤维有助于改善这一缺陷。相对于单掺纤维混凝土,将不同品质、不同几何形态的纤维混掺入混凝土中,可以从不同层次上改善纤维分布的均衡性,提高增强效率。本文通过实验的手段,研究钢纤维-PVA纤维混杂、钢纤维-玄武岩纤维混杂的混凝土基本力学性能与抗爆性能。通过立方体抗压试验、劈裂抗拉试验、弯曲韧性试验以及混杂纤维混凝土板的接触爆炸试验,探讨不同纤维掺量对混凝土性能的影响。其中,钢纤维掺量取3个体积率:0.5%、1%、2%,PVA纤维掺量取3个体积率:0.05%、0.1%、0.15%,玄武岩纤维掺量取1个体积率:0.1%,共12组配合比。得到结论如下:(1)在混凝土中加入不同纤维对混凝土的抗压强度影响不大。混杂纤维混凝土受压破坏后呈多缝开裂的形态。钢纤维掺量对抗压强度起主要的影响作用。在钢纤维掺量较大(2%)时,抗压强度提高约20%左右。当钢纤维掺量较低(0.5%～1%)时,混杂纤维混凝土的抗压强度比之素混凝土会相对降低。在混凝土中加入玄武岩纤维对混杂纤维混凝土的抗压强度几乎没有影响。(2)混杂纤维可以提高混凝土的抗拉强度,提高约23%～103%。对提高混杂纤维混凝土抗拉强度起主要作用的纤维是钢纤维。在低钢纤维掺量(0.5%)的情况下,混杂纤维混凝土的抗拉强度可以至少提高20%。(3)在混凝土中加入混杂纤维对提高混凝土的初裂强度、极限抗弯承载力、弯曲韧性有利。最为明显的是,在素混凝土中加入混杂纤维可将弯曲韧性提高约6～15倍。随着钢纤维掺量的增加,弯曲韧性也增加,随着PVA纤维掺量的增加,弯曲韧性先减后增,但基本在一定范围内浮动。玄武岩纤维的表现没有优于或劣于PVA纤维。(4)混杂纤维可以改善混凝土的脆性性质,表现在纤维的存在可以增大混凝土的拉压比。随着钢纤维掺量的增加,拉压比增加,随着PVA纤维掺量的增加,拉压比也增大。掺入玄武岩纤维的混杂纤维混凝土在钢纤维掺量为1%与2%时,拉压比相差无几。(5)与普通钢筋混凝土板相比,混杂纤维钢筋混凝土板的抗爆能力较好,尤其体现在背爆面的震塌情况上。用破坏系数Ka、Kb来表示混杂纤维钢筋混凝土板的抗爆能力时,当短纤维的掺量低时(PVA纤维0.05%或BF0.1%),在钢纤维低掺量区(1%)提高钢纤维掺量对增强混杂纤维混凝土的抗爆能力效果明显。而当短纤维的掺量高时(PVA纤维0.1%～0.15%),在钢纤维高掺量区(1%)提高钢纤维掺量对增强混杂纤维混凝土的抗爆能力效果更明显。
[Abstract]:As a multi-phase material, concrete has micro cracks before force, and the addition of fiber in concrete helps to improve this defect. Compared with single fiber reinforced concrete, mixing fibers with different quality and geometric shapes can improve the equilibrium of fiber distribution and enhance efficiency at different levels. In this paper, the basic mechanical properties and anti explosion properties of steel fiber -PVA fiber hybrid, steel fiber - basalt fiber hybrid concrete are studied by means of experimental methods. Through cube compression test, splitting tensile test, flexural toughness test and contact explosion test of hybrid fiber reinforced concrete plate, the influence of different fiber content on the performance of concrete is discussed. Among them, the volume fraction of steel fiber is 3 volume rate: 0.5%, 1% and 2%, and the volume fraction of PVA fiber is 3 volume rate: 0.05%, 0.1% and 0.15%, and the volume fraction of basalt fiber is 1 volume fraction: 0.1%, the total 12 group proportion. The conclusions are as follows: (1) the addition of different fibers in concrete has little effect on the compressive strength of concrete. The fracture of hybrid fiber concrete is multiple crack after being subjected to pressure. The content of steel fiber admixtures against the pressure degree. When the steel fiber content is larger (2%), the compressive strength is about 20%. When the amount of steel fiber is low (0.5% to 1%), the compressive strength of the hybrid fiber concrete is lower than that of the plain concrete. The addition of basalt fiber to the concrete has little effect on the compressive strength of the hybrid fiber concrete. (2) the tensile strength of concrete can be improved by hybrid fiber, which is about 23% to 103%. The fiber which plays an important role in improving the tensile strength of hybrid fiber concrete is steel fiber. In the case of low steel fiber content (0.5%), the tensile strength of hybrid fiber concrete can be increased by at least 20%. (3) adding hybrid fiber to concrete is beneficial to improve the initial crack strength, ultimate bending bearing capacity and flexural toughness of concrete. The most obvious is that adding hybrid fibers to the plain concrete can increase the flexural toughness by about 6~15 times. With the increase of steel fiber content, the flexural toughness also increases. With the increase of PVA fiber content, the flexural toughness decreases first and then increases, but it fluctuate in a certain range. The performance of basalt fiber is not superior to or inferior to PVA fiber. (4) the hybrid fiber can improve the brittle properties of concrete, which shows that the existence of fiber can increase the tensile ratio of concrete. With the increase of the amount of steel fiber, the ratio of tension and pressure increases. With the increase of the amount of PVA fiber, the ratio of tension and pressure increases. The mixed fiber reinforced concrete with basalt fiber is different when the steel fiber content is 1% and 2%. (5) compared with the ordinary reinforced concrete slab, the anti explosion ability of the hybrid fiber reinforced concrete slab is better, especially in the case of the collapse of the back surface. When using the destruction coefficient Ka and Kb to express the antiknock ability of hybrid fiber reinforced concrete slabs, when the short fiber content is low (PVA fiber 0.05% or BF0.1%), the effect of increasing the amount of steel fiber on the antiknock ability of reinforced hybrid fiber concrete is obvious in the low volume area of steel fiber (1%). When the short fiber content is high (PVA fiber 0.1% ~ 0.15%), the effect of increasing the amount of steel fiber on the antiknock ability of the hybrid fiber reinforced concrete is more obvious when the steel fiber content is high (1%).
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU528.572

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