钢纤维缓和骨料混凝土抗拉性能试验研究

【作者】 李晓虎；

【导师】 张燕坤；

【作者基本信息】 北方工业大学 ， 结构工程， 2012， 硕士

【摘要】 钢纤维混合骨料混凝土是在混合骨料混凝土中掺入钢纤维的一种新型复合材料。钢纤维具有较强的抗拉强度,散乱分布在混凝土中。可阻碍混凝土内部微裂缝的扩展和阻滞宏观裂缝的发生和发展,显著提高混凝土的抗拉、抗弯及抗剪强度,抗冲击、抗疲劳,裂后韧性和耐久性也有较大改善。目前,国内外对于钢纤维混合骨料混凝土的研究还比较少。本文运用正交设计的试验方法,通过轴心抗拉试验和劈裂抗拉试验,分析了水胶比、轻骨料掺量、钢纤维体积掺量等因素对钢纤维混合骨料混凝土抗拉强度的影响,并论述了钢纤维对混凝土的增韧作用。根据论文的研究目的,试验设计了25组配合比,共制作225个试块包括标准抗压强度试验、轴心抗拉强度试验和劈裂抗拉强度试验。结果分析表明：(1)钢纤维的加入能够很好的提高混合骨料混凝土的抗拉性能。(2)钢纤维有很好的增韧效果,可以使混凝土试块在破坏以后裂而不散。(3)钢纤维混合骨料混凝土劈裂抗拉强度和抗压强度比值在1/9～1/15的范围,轴心抗拉强度和劈裂抗拉强度之间的比值约为0.79。(4)钢纤维混合骨料混凝土的表观密度随着轻骨料掺量的增加而降低,轻骨料掺量每增加120%混凝土的表观密度下降约105kg/m3。本文的试验结果可以为钢纤维混合骨料混凝土的研究和工程应用提供参考依据。更多还原

【Abstract】 The specified density steel fiber concrete is a new type of composite material which is mixed in the combined aggregate concrete with short steel fiber. The steel fiber has good tensile strength, scattered distribution in concrete. This can prevent the propagation of micro crack and macro crack in concrete and improve the tensile strength, flexural strength and shearing strength of specified density steel fiber concrete. Its shock resistance, fatigue resistance and fracture toughness also have bigger improvement. At present, the research on specified density steel fiber concrete is still relatively small at home and abroad.This paper uses orthogonal design method, through the experiments of cube splitting tensile strength and axial tensile strength, analyzes the water-cement ratio, lightweight replacement rate and steel fiber replacement rate and other factors on tensile strength of specified density steel fiber concrete. The toughening effect of steel fiber on concrete is also suggested. According to research objective,25groups of mix proportion and225test block have been made including cube compressive strength test, axial tensile strength test and splitting tensile strength test.The test result shows that:(1)The addition of steel fiber could improve the tensile performance of combined aggregate to some extent.(2)Steel fiber has good toughening effect which could make the test block of concrete destruction of crack without powder.(3)The ratio of splitting tensile strength and cube compressive strength is between1/9-1/15, the ratio of axial tensile strength and splitting tensile strength is about0.79.(4)With the increase of the volume fraction of steel fiber, elastic tensile modulus is rising somewhat. And apparent density is also affected little.The results of this paper can provide a reference for research and engineering application of specified density steel fiber concrete.更多还原