再生混凝土骨料改性研究及其应用

发布时间：2018-02-05 02:09

本文关键词： 再生混凝土再生粗骨料性质骨料改性力学性能应用　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：21世纪以来我国大力发展建筑业,产生了庞大的建筑垃圾,由于对建筑垃圾不恰当的处理方式,极大地危害了我们赖以存活的自然环境;另一方面生产建筑材料需要大量开采大量的自然资源,对生态环境和自然资源构成重大威胁。将建筑垃圾回收、加工再利用,不仅可以解决建筑垃圾对自然环境的破坏,也可缓解因沙石开采对生态构成的威胁,所以将废旧混凝土进行有效合理利用对解决这些问题极具重要意义。本文对再生骨料的基本特性、改性处理、混凝土力学性能以及再生骨料在道路工程中的应用作了研究。试验发现天然混凝土相比再生粗骨料密度低、孔隙率高、吸水率高、含水率高、压碎指标值高、坚固性较差、含泥量较高。对五种不同品质的粗骨料(天然骨料,再生骨料,在浓度5%水玻璃溶液中浸泡1h处理后的再生骨料,在浓度10%溶液中浸泡24h处理后的再生骨料,在浓度8%硅烷乳液中浸泡24h处理后的再生骨料)的表观密度、堆积密度、吸水率及压碎指标进行了测试;结果表明通过再生骨料改性手段可以使再生骨料的基本性能得到改善;经过水玻璃溶液、PVA溶液及硅烷乳液处理后的再生骨料的表观密度、堆积密度及压碎指标值都有所增加,吸水率降低明显。三种试剂改性再生骨料最佳浓度和浸泡时间:水玻璃5%浓度浸泡1h、PVA 10%浓度浸泡24h、硅烷8%浓度浸泡24h。通过实验测定了由这五种不同品质的粗骨料配制的混凝土的力学性能;再生粗骨料再生混凝土立方体抗压强度、轴心抗压强度、劈裂抗拉强度均明显小于同龄期的天然混凝土,再生混凝土的力学性能损失通过再生骨料的改性处理得到改善,利用PVA溶液改性处理的再生混凝土的力学性能改善效果最好,其次是水玻璃溶液,硅烷乳液改性的再生骨料对再生混凝土早起强度的提高优于其他两种试剂。最后研究了再生粗骨料在道路工程中的应用;我国在一些道路中的路基和路面部位使用再生混凝土,作为试验研究的路段,其效果良好。再生粗骨料配制的二灰稳定再生骨料用于再生混凝土道路基层中,效果良好;再生混凝土用于道路面层中现有的研究不足,需更一步探究。
[Abstract]:Since 21th century, China has vigorously developed the construction industry, resulting in a large amount of construction waste, because of the improper disposal of construction waste, it has greatly damaged the natural environment on which we rely for survival. On the other hand, the production of building materials needs to exploit a large number of natural resources, which poses a major threat to the ecological environment and natural resources. It can not only solve the damage to the natural environment caused by construction waste, but also alleviate the threat to ecology caused by sand and stone mining. Therefore, the effective and reasonable utilization of waste concrete is of great significance to solve these problems. The basic characteristics of recycled aggregate, modified treatment in this paper. The mechanical properties of concrete and the application of recycled aggregate in road engineering are studied. It is found that natural concrete has lower density, higher porosity, higher water absorption, higher moisture content and higher crushing index than recycled coarse aggregate. For five kinds of coarse aggregate (natural aggregate, regenerated aggregate, soaked in 5% sodium silicate solution for 1 h), the coarse aggregate of five different qualities (natural aggregate, regenerated aggregate) is poor in firmness and high in mud content. The apparent density and bulk density of regenerated aggregate after immersion in 10% solution for 24 hours and recycled aggregate after immersion in 8% silane emulsion for 24 hours. The water absorption rate and crushing index were tested. The results show that the basic properties of recycled aggregate can be improved by means of modification of recycled aggregate. The apparent density, bulk density and crushing index value of regenerated aggregate treated with PVA solution and silane emulsion were increased. The optimum concentration and soaking time of regenerated aggregate modified by three reagents were as follows: water glass 5% concentration soaking for 1 h and PVA 10% concentration soaking for 24 h. The mechanical properties of concrete prepared from five kinds of coarse aggregate with different quality were tested by immersion of silane 8% for 24 hours. The cube compressive strength, axial compressive strength and splitting tensile strength of recycled coarse aggregate recycled concrete are obviously lower than those of natural concrete of the same age. The loss of mechanical properties of recycled concrete is improved by the modification of recycled aggregate. The improvement of mechanical properties of recycled concrete treated by PVA solution is the best, followed by sodium silicate solution. The recycled aggregate modified by silane emulsion can improve the early strength of recycled concrete better than the other two reagents. Finally, the application of recycled coarse aggregate in road engineering is studied. Recycled concrete is used in roadbed and pavement of some roads in our country. As the experimental research section, the effect is good. The reclaimed coarse aggregate prepared by lime-fly ash stabilized recycled aggregate is used in recycled concrete road base. The effect is good; The existing research of recycled concrete in road surface is insufficient and needs further exploration.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528.041

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