粉煤灰替代细骨料的混凝土性能研究

发布时间：2018-04-19 19:57

本文选题：粉煤灰 + 细骨料　；参考：《江苏科技大学》2017年硕士论文

【摘要】：本文以粉煤灰替代细骨料的混凝土为研究对象,对不同养护龄期、不同替代率的粉煤灰替代细骨料的混凝土的立方体抗压强度、棱柱体轴心抗压强度、劈裂抗拉强度、抗折强度、弹性模量、碳化深度以及微观检测等分别进行了试验研究。研究的主要内容包括:1.同一水灰比下,粉煤灰替代细骨料的替代率对混凝土立方体抗压强度、棱柱体轴心抗压强度、劈裂抗拉强度和抗折强度的影响。2.混凝土的龄期对粉煤灰替代细骨料的混凝土立方体抗压强度、棱柱体轴心抗压强度、劈裂抗拉强度和抗折强度的影响。3.对不同替代率的粉煤灰替代细骨料的混凝土进行弹性模量测试,并根据测试结果进行分析;分别对普通混凝土和不同替代率的粉煤灰替代细骨料的混凝土进行不同碳化时间的碳化深度测试并分析;对不同时期的粉煤灰替代细骨料的混凝土进行微观检测,并根据电镜扫描的结果进行分析;对粉煤灰替代细骨料的混凝土与普通混凝土进行成本分析,并计算出两种混凝土的成本差值。4.分析试验数据,在满足强度、和易性的前提下寻求合理替代率,以便应用于工程实践当中,同时为实际工程提供必要的参考资料。5.建立粉煤灰替代不同量细骨料情况下混凝土的抗压强度、劈裂抗拉强度、抗折强度的预测模型,模型中取代率权重变化因子只与龄期有关。研究结果表明:不同替代率的粉煤灰替代细骨料的混凝土的立方体抗压强度、劈裂抗拉强度、轴心抗压强度都比未替代的混凝土的好,但是随着替代率的不断增大粉煤灰替代细骨料的混凝土的和易性越来越差,需要添加减水剂才能满足和易性的要求。除此之外,粉煤灰替代细骨料的混凝土的抗折强度略低于未替代的混凝土,但基本上能满足工程要求。在不同粉煤灰替代率下,替代率为45%时的粉煤灰替代细骨料的混凝土的立方体抗压强度、劈裂抗拉强度、轴心抗压强度、抗折强度、弹性模量和碳化性能等各方面性能均最优,并且制作成本远低于未替代的混凝土,可大量应用于实际工程中。粉煤灰替代细骨料的混凝土的强度之所以增长,主要是因为水泥水化产物与粉煤灰中的SiO2和Al2O3进行了二次反应,其最终反应产物使混凝土内部各个物质结合紧密,从而提高了粉煤灰替代细骨料的混凝土的强度。
[Abstract]:In this paper, the concrete with fly ash instead of fine aggregate is studied. The cubic compressive strength, the axial compression strength of prism, the splitting tensile strength, the flexural strength, the modulus of elasticity, the depth of carbonization and the microscopic examination of the concrete with different curing age and different replacement rates in substitutes for the fine aggregate are tested. The main contents are as follows: 1. under the same water cement ratio, the substitution rate of fly ash instead of fine aggregate affects the compressive strength of concrete cube, the axial compression strength of prism, splitting tensile strength and flexural strength. The concrete cube compressive strength of fly ash instead of fine aggregate, the axial compression strength of prism, splitting of the axial compression strength of the prism, the splitting of the axial compressive strength of the concrete, and the splitting of the concrete cube in the concrete cube compression strength, the concrete cube compression strength, the concrete cube compression strength, the concrete cube compressive strength, the concrete cube compression strength, the.2. concrete cube compressive strength and the axial compressive strength of the prism body, the axial compression strength of the prism body, and the splitting strength of the concrete, The influence of tensile strength and flexural strength on the modulus of elasticity of the concrete with different substitution rate of fly ash substitute for fine aggregate concrete was tested and analyzed according to the test results. The carbonization depth of different carbonation time of concrete and concrete with different substitution rate of fly ash instead of fine aggregate was tested and analyzed, respectively. The concrete of different period of fly ash replacing the fine aggregate concrete is examined and analyzed according to the results of the scanning electron microscope. The cost analysis of the concrete and the ordinary concrete with the fly ash instead of the fine aggregate is analyzed, and the cost difference.4. analysis test number of two kinds of concrete is calculated, and the combination of the strength and the ease of the concrete is sought. In order to be used in engineering practice so as to be used in engineering practice, and to provide the necessary reference material for practical engineering,.5. can be used to establish the prediction model of compressive strength, splitting tensile strength and flexural strength of concrete under the condition of fly ash instead of different quantities of fine aggregate. The weight variation factor of the substitution rate in the model is only related to the age period. The substitution rate of fly ash substitute for the cube compressive strength, splitting tensile strength and the axial compression strength of the concrete, which is better than that of the unreplaced concrete. But with the increasing substitution rate of the concrete that the fly ash substitute for the fine aggregate is getting worse and worse, it is necessary to add water reducing agent to meet the requirements of the workability. In addition, the flexural strength of concrete with fly ash substitutes for fine aggregate is slightly lower than that of unreplaced concrete, but it can basically meet the engineering requirements. Under the different substitution rate of fly ash, the replacement ratio is 45% of the cubic compressive strength, splitting tensile strength, axial compression strength, flexural strength and modulus of elasticity of concrete with fly ash instead of fine aggregate And the carbonization performance is the best, and the production cost is far lower than the unsubstituted concrete. It can be used in practical engineering. The strength of the concrete with fly ash instead of fine aggregate is increasing, mainly because the cement hydration products and the SiO2 and Al2O3 in the fly ash have two reactions, and the final reaction products are mixed. The cohesion of various materials inside the condensate increases the strength of concrete with fly ash instead of fine aggregate.

【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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