再生骨料裹浆处理技术研究

发布时间：2018-04-20 11:44

本文选题：再生混凝土 + 壳体厚度模型　；参考：《西北农林科技大学》2015年硕士论文

【摘要】：再生骨料混凝土由于其具有环境保护和资源节约的特点,越来越受到研究者的关注。但是由于其自身具有的一些先天缺陷因素,导致再生骨料混凝土在应用时受到一定的限制。本文从再生骨料改性的角度出发,提出一个以壳体厚度为标准的评价指标,并对其合理性进行验证。论文首先重点研究使用矿粉类浆液裹浆处理不同水灰比下的裹浆厚度,通过水膜推算面积的方法推算再生粗骨料的平均表面积,并用分形理论计算验证。利用改性处理后的质量增量计算出再生粗骨料(卵石)的裹浆厚度模型,并从不同裹浆厚度的角度重新测定处理后再生骨料的各项指标数值,探讨裹浆厚度对于再生粗骨料的性能影响规律;以相同配合比,不同裹浆厚度、不同再生骨料取代率、不同粉煤灰掺量为因素,设计3因素4水平的正交试验。通过试验测定再生混凝土的抗压强度和劈裂抗拉强度,得到3个因素对于再生混凝土力学性能的影响规律;按照粉煤灰、再生骨料取代率在力学性能上的最优组合,进行了混凝土耐久性试验研究,研究主裹浆厚度对于再生混凝土耐久性的影响规律。文章最后分析相关因素的主要作用机理和经济上的可行性,并从指导实际生产的角度出发,提出了制造的再生骨料优化工艺模型。基于以上的研究得出的主要结论为:(1)根据试验数据得到再生骨料矿粉类材料裹浆厚度计算公式,公式分线性拟合和非线性拟合。(2)通过裹浆厚度对于再生骨料性能的影响机理的研究,认为裹浆厚度不宜过厚或者过薄,裹浆的最优厚度宜为0.15~0.25mm之间,并且外掺料的粒径越小越适合较高的裹浆厚度,粒径越大裹浆厚度宜取小值。(3)粉煤灰掺量20%、骨料取代率30%时,再生骨料混凝土的力学性能最优;提高抗渗性能和抗冻性能的骨料裹浆厚度为0.20~0.15mm。再生混凝土性能和再生骨料性能指标呈现正相关关系,适当的浆壳厚度对再生混凝土的耐久性能提升显著。(4)提出再生骨料制造和加工的改进工艺流程,绘制出工艺流程示意图。
[Abstract]:Recycled aggregate concrete has attracted more and more attention because of its environmental protection and resource saving. However, due to some inherent defects, recycled aggregate concrete is limited in application. From the point of view of the modification of recycled aggregate, this paper presents an evaluation index based on shell thickness, and verifies its rationality. In this paper, the thickness of slurry wrapped with mineral powder slurry under different water / cement ratio is studied, and the average surface area of recycled coarse aggregate is calculated by water film calculation method, which is verified by fractal theory. The slurry thickness model of recycled coarse aggregate (pebble) was calculated by using the quality increment after modified treatment, and the index values of recycled aggregate after treatment were re-determined from the angle of different slurry thickness. The effect of slurry thickness on the properties of recycled coarse aggregate was discussed. The orthogonal experiment was designed at 3 factors and 4 levels with the same mixture ratio, different slurry thickness, different replacement rate of recycled aggregate and different fly ash content. By testing the compressive strength and splitting tensile strength of recycled concrete, the influence of three factors on the mechanical properties of recycled concrete is obtained. In this paper, the durability of recycled concrete is studied by experimental study on the influence of the thickness of main slurry on the durability of recycled concrete. In the end of this paper, the main mechanism and economic feasibility of the related factors are analyzed, and from the point of view of guiding the actual production, the optimization process model of recycled aggregate is put forward. Based on the above research, the main conclusion is: (1) based on the experimental data, the formula for calculating the slurry thickness of recycled aggregate mineral powder material is obtained. The formula is divided into linear fitting and nonlinear fitting. (2) based on the study of the influence mechanism of slurry thickness on the properties of recycled aggregate, it is considered that the thickness of slurry wrapping should not be too thick or too thin, and the optimum thickness of slurry wrapping should be between 0.15~0.25mm. And the smaller the particle size of the admixture, the more suitable for the higher slurry thickness, the bigger the particle size is, the smaller the thickness of the slurry is, the smaller the content of fly ash is 20, the ratio of replacement of aggregate is 30, the mechanical properties of recycled aggregate concrete are the best. The thickness of aggregate slurry for improving impermeability and freezing resistance is 0.20 ~ 0.15mm. There is a positive correlation between the properties of recycled concrete and the properties of recycled aggregate, and the proper thickness of slurry shell can significantly improve the durability of recycled concrete. (4) the improved technological process of recycled aggregate manufacturing and processing is proposed, and the process flow diagram is drawn.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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