快速修复路面的混杂纤维水泥混凝土基本性能试验研究

发布时间：2018-05-24 20:56

本文选题：路面水泥混凝土 + 钢纤维　；参考：《辽宁工业大学》2017年硕士论文

【摘要】：在路面铺装工程中,水泥混凝土是应用最广泛的建筑材料,但其自身存在抗拉抗折强度低、脆性大和耐久性差等缺点,容易导致路面的损坏。普通的水泥混凝土修复材料工期长,影响交通,因此需要采用快速修复材料以实现在短时间内通车的要求。在路面水泥混凝土中掺加纤维可显著提高混凝土的抗拉抗折强度和耐久性,起到增强韧性的作用。同目前研究相对成熟的单一纤维混凝土相比较,本文采用不同材质的纤维混杂掺入路面水泥混凝土中研究路面水泥混凝土的基本力学性能和耐久性。本文首先通过经验公式求得路面水泥混凝土初步配合比,然后再用正交试验设计方法进行配合比的优选,并用极差分析法分析各因素对路面水泥混凝土抗折强度的影响,确定快速修复路面的水泥混凝土最优配合比。在最优配合比基础上掺入钢纤维和聚丙烯腈纤维,研究不掺纤维、掺入单一纤维和掺入混杂纤维对路面水泥混凝土的基本力学性能和早期抗裂性能的影响,并定义了混杂纤维最优混杂比例的评价公式,利用该公式分析出混杂纤维的最佳掺量。在最佳混杂纤维掺量基础上以再生粗骨料替代天然粗骨料,研究再生粗骨料对混杂纤维再生水泥混凝土的基本力学性能和抗冻性能的影响。由于在路面工程设计中以抗折强度为强度设计依据,因此本文在抗冻性试验时除规定的抗压强度的冻融循环试验外,还研究经过冻融循环后,再生粗骨料对路面混凝土抗折强度损失的影响。试验结果表明:(1)掺入单一钢纤维,抗压强度、抗折强度、劈裂抗拉强度和抗压弹性模量都有显著的提高。掺入聚丙烯腈纤维,抗折强度、劈裂抗拉强度和抗压弹性模量有一定的提高,立方体抗压强度略有提高。当掺入两者混杂纤维,抗压强度比未掺纤维的混凝土有一定的提高,抗折强度、抗压弹性模量和劈裂抗拉强度有显著提高,提高程度取决于纤维掺量和比例的混杂效应。(2)路面混杂纤维再生水泥混凝土抗压强度有一定程度的降低,抗折强度和劈裂抗拉强度呈现显著降低,基本力学性能降低程度取决于再生粗骨料的掺入量。对掺入再生粗骨料和未掺入再生粗骨料的混杂纤维混凝土进行冻融试验,发现混杂纤维再生混凝土的抗冻性能低于混杂纤维混凝土,但影响并不显著。混杂纤维再生混凝土的抗冻性能取决于再生粗骨料的掺入量。(3)路面混杂纤维水泥混凝土和路面混杂纤维再生水泥混凝土的抗压强度、抗折强度、劈裂抗拉强度都满足3天通车条件,达到28天二级公路路面混凝土的强度要求。
[Abstract]:In pavement engineering, cement concrete is the most widely used building material, but its own shortcomings such as low tensile strength, high brittleness and poor durability can easily lead to pavement damage. Ordinary cement concrete repair materials have long construction period and affect traffic, so it is necessary to adopt rapid repair materials to meet the requirement of opening to traffic in a short time. The addition of fiber in pavement cement concrete can significantly improve the tensile strength and durability of concrete and enhance its toughness. Compared with single fiber concrete which is relatively mature at present, the basic mechanical properties and durability of pavement cement concrete are studied in this paper by mixing fibers of different materials into pavement cement concrete. In this paper, the initial mix ratio of pavement cement concrete is obtained by empirical formula, then the optimum mix ratio is selected by orthogonal test design method, and the influence of various factors on the flexural strength of pavement cement concrete is analyzed by means of range analysis method. Determine the optimum mix ratio of cement concrete for rapid pavement repair. Based on the optimum mix ratio, the effects of steel fiber and polyacrylonitrile fiber on the basic mechanical properties and early crack resistance of pavement cement concrete were studied. The formula for evaluating the optimal mixing ratio of hybrid fibers was defined, and the optimum blending amount of hybrid fibers was analyzed by using the formula. The influence of recycled coarse aggregate on the basic mechanical properties and frost resistance of hybrid fiber recycled cement concrete was studied on the basis of the optimum content of hybrid fiber in place of natural coarse aggregate. Because the flexural strength is taken as the basis for strength design in pavement engineering design, in addition to the freeze-thaw cycle test of the specified compressive strength, this paper also studies the freeze-thaw cycle after freeze-thaw cycle test. Effect of recycled coarse aggregate on flexural strength loss of pavement concrete. The experimental results show that the compressive strength, flexural strength, splitting tensile strength and compressive elastic modulus of single steel fiber are improved significantly. The flexural strength, splitting tensile strength and compressive elastic modulus of polyacrylonitrile fiber are improved, while the cube compressive strength is slightly improved. The compressive strength of the mixed fiber is higher than that of the concrete without the fiber, and the flexural strength, compressive elastic modulus and splitting tensile strength are improved significantly. The degree of improvement depends on the mixing effect of fiber content and proportion. (2) the compressive strength of hybrid fiber recycled cement concrete on pavement is reduced to some extent, and the flexural strength and splitting tensile strength are obviously decreased. The reduction of basic mechanical properties depends on the amount of recycled coarse aggregate. The freezing and thawing tests of hybrid fiber reinforced concrete with and without recycled coarse aggregate show that the frost resistance of hybrid fiber recycled concrete is lower than that of hybrid fiber reinforced concrete, but the effect is not significant. The frost resistance of hybrid fiber recycled concrete depends on the amount of recycled coarse aggregate.) the compressive strength and flexural strength of hybrid fiber reinforced cement concrete and hybrid fiber recycled cement concrete on road surface. The splitting tensile strength can meet the requirement of 3 days' opening and 28 days' concrete strength of the second class highway pavement.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U414

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