再生水泥混凝土配合比设计及钢纤维对其性能影响研究

发布时间：2018-05-14 13:25

本文选题：再生混凝土 + 钢纤维　；参考：《长沙理工大学》2015年硕士论文

【摘要】：再生混凝土作为一种“绿色”混凝土,不仅可以降低成本、节约资源,同时也可以减轻对环境的污染。目前再生混凝土在实际工程中已得到许多应用,对再生骨料、再生混凝土性能及应用的研究工作也日益受到重视。本文通过正交试验,研究水灰比、砂率、取代率对再生混凝土性能的影响；从而选定一组最佳的配合比,研究再生混凝土的耐磨性、抗冲击性以及钢纤维的加入对其性能的影响；并提出了两种新型取代方式,研究了在不同取代方式下再生混凝土的早期抗压强度。本文主要研究内容及成果如下：1、设计两种级配方式,分别采用两种级配方式对再生粗骨料的表观密度、堆积密度、吸水率和压碎指标进行试验研究,最后通过综合分析选取一种性能较优的级配方式,并确定再生粗骨料等级；2、选取水灰比、再生粗骨料取代率、砂率三个影响因素,以再生粗骨料水泥混凝土的抗压强度和抗折强度作为试验指标,通过正交试验极差分析,得到了三个因素对再生粗骨料水泥混凝土性能影响的主次顺序,并通过综合分析,选取最佳配合比和再生粗骨料取代率；3、进行了再生粗骨料水泥混凝土的耐磨性和抗冲击性试验,通过试验发现,在满足再生粗骨料水泥混凝土抗压强度、抗折强度的同时,其耐磨性和抗冲击性也良好,其抗冲击性甚至优于天然粗骨料水泥混凝土；4、提出两种新型再生粗骨料取代方式：大粒径取代方式、小粒径取代方式,探讨研究了在相同的取代率下,不同取代方式对再生粗骨料水泥混凝土早期抗压强度的影响。试验结果表明,无论在何种取代率下,大粒径取代方式下再生粗骨料水泥混凝土的早期抗压强度最优,其次是全粒径取代,再次是小粒径取代。5、试验研究了钢纤维再生粗骨料水泥混凝土及钢纤维天然粗骨料水泥混凝土28天抗压强度、抗折强度和抗冲击性能。研究表明,适量钢纤维的加入可以大幅度提高再生粗骨料水泥混凝土和天然粗骨料水泥混凝土的抗压强度、抗折强度和抗冲击性能。本文提出的再生粗骨料水泥混凝土配合比设计技术在长沙市黄兴南路改公交车道等项目中得到了应用,节省了工程投资,取得了显著的社会、环境和经济效益。
[Abstract]:As a kind of "green" concrete, recycled concrete can not only reduce the cost, save the resources, but also reduce the pollution to the environment. At present, recycled concrete has been used in many practical projects, and the research work on recycled aggregate, recycled concrete performance and its application has been paid more and more attention. In this paper, the effects of water-cement ratio, sand ratio and substitution rate on the properties of recycled concrete are studied by orthogonal test, and the wear resistance of recycled concrete is studied by selecting a group of optimum mix ratio. The impact resistance and the effect of steel fiber addition on the properties of recycled concrete were studied, and two new substitution methods were proposed to study the early compressive strength of recycled concrete. The main contents and results of this paper are as follows: 1. Two gradation methods are designed. The apparent density, accumulation density, water absorption and crushing index of recycled coarse aggregate are studied by using two gradation methods, respectively. Finally, by synthetically analyzing and selecting a better gradation method, three influencing factors are determined: grade 2 of recycled coarse aggregate, ratio of water to cement, replacement rate of regenerated coarse aggregate, sand rate, etc. The compressive strength and flexural strength of recycled coarse aggregate cement concrete are taken as the test indexes. By means of orthogonal test range analysis, the primary and secondary order of three factors affecting the performance of recycled coarse aggregate cement concrete is obtained, and the comprehensive analysis is carried out. The wear resistance and impact resistance of recycled coarse aggregate cement concrete were tested by selecting the optimum mix ratio and the replacement ratio of recycled coarse aggregate. It was found that the compressive strength and flexural strength of recycled coarse aggregate cement concrete were satisfied at the same time. Its wear resistance and impact resistance are also good, and its impact resistance is even better than that of natural coarse aggregate cement concrete. The influence of different substitution methods on the early compressive strength of recycled coarse aggregate cement concrete under the same substitution rate was studied. The experimental results show that the early compressive strength of recycled coarse aggregate cement concrete is the best under the substitution rate of large particle size, followed by the replacement of total particle size. Second, the small particle size replaced .5. the compressive strength, flexural strength and impact resistance of steel fiber regenerated coarse aggregate cement concrete and steel fiber natural coarse aggregate cement concrete were studied in 28 days. The results show that the compressive strength, flexural strength and impact resistance of recycled coarse aggregate cement concrete and natural coarse aggregate cement concrete can be greatly improved by adding appropriate steel fiber. In this paper, the design technology of recycled coarse aggregate cement concrete mixture ratio has been applied in the transformation of Huangxing South Road to bus path in Changsha City, which has saved the project investment and achieved remarkable social, environmental and economic benefits.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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