再生砖骨料植生混凝土制备技术和工程应用研究

发布时间：2018-06-04 02:03

本文选题：再生砖 + 植生混凝土　；参考：《山东农业大学》2014年硕士论文

【摘要】：随着我国经济的快速发展和城市建设步伐的加快、新农村建设工作的不断深入及旧农村改造,地面被大量的建筑物和混凝土道路所覆盖,城市绿色植被面积明显减少,热岛效应加剧,同时城乡拆迁产生了大量的废弃砖,造成了资源的浪费；利用废弃砖作为植生混凝土再生骨料既可以解决废弃粘土砖造成的污染,又可以改善生态环境。植生混凝土在国外已经发展的比较成熟,而在国内的却刚刚起步,许多学者已经取得一些成果,但利用废弃砖再生骨料制备植生型多孔连续型混凝土方面的研究还未见相关报道,因此,研究再生砖骨料植生混凝土非常有必要。本文在借鉴国外研究成果的同时,立足于国内的研究现状,针对再生砖骨料植生混凝土结构的特点,着重研究再生砖瓦骨料植生混凝土的制备方法、降碱和植生技术,为工程应用提供参考。试验研究结果表明： (1)针对碎砖集料吸水率高、强度低的特点,提出了采用二次裹浆法提升再生砖骨料性能。针对再生砖骨料植生混凝土在国内的研究较少这一现状,目前还没有统一合理的配合比设计方法,提出了以空隙率为主要设计参数,强度为次要设计参数的设计思路。水灰比初配试验证明：当水灰比在0.29-0.33时,水泥砂浆具有一定的流动性和粘聚性；最佳水灰比为0.31,目标空隙率为30%,再生砖骨料植生混凝土的强度为4.92MPa,满足了工程护坡的要求。针对再生砖骨料植生混凝土空隙率大、骨料吸水率高的特点,配合比可用“饱和骨料体积法”计算。 (2)本文在分析植生混凝土内部孔隙碱类物质的来源、存在形态后,设计了用清水浸泡和用FeSO4溶液处理两种方法改造再生砖骨料植生混凝土孔隙内碱性的对比试验。试验表明：用清水隔天换水可以将再生砖骨料植生混凝土孔隙内的PH降到9-10之间；用FeSO4溶液处理后的植生混凝土孔隙内的PH能达到8-9之间,但对强度有定的破坏。综合考虑,用清水浸泡处理是一种改善再生砖骨料植生混凝土孔隙内碱性水环境的有效方法,工程中可以通过延长自然养护时间达到降碱目的。 (3)针对工程应用中实际要求,分析了种植基质、草种的种类和选材原则,研究不同的种植基质对再生砖骨料植生混凝土上的植物生长状况的植生试验,试验表明：将种植基质、土壤与种子等按照一定比例搅拌均匀后,采取灌浆法或分层播种法填充在再生砖骨料植生混凝土内部空隙,加上必要的养护与管理,植物可以在上健康良好的生长。
[Abstract]:With the rapid development of our economy and the acceleration of the pace of urban construction, the construction of new rural areas and the reconstruction of old rural areas, the ground is covered by a large number of buildings and concrete roads, and the area of urban green vegetation is obviously reduced. The heat island effect is intensified, at the same time, a large number of abandoned bricks are produced in urban and rural demolition, resulting in a waste of resources. The use of waste bricks as recycled aggregate of planting concrete can not only solve the pollution caused by abandoned clay bricks, but also improve the ecological environment. Planting concrete has developed more mature in foreign countries, but it has just started in China. Many scholars have already made some achievements. However, the research on the preparation of porous continuous concrete with recycled brick aggregate has not been reported. Therefore, it is necessary to study the recycled brick aggregate planting concrete. According to the characteristics of recycled brick aggregate planting concrete structure, the preparation method, alkali reduction and planting technology of recycled brick and tile aggregate planting concrete are studied in this paper. It provides reference for engineering application. The experimental results show that: 1) aiming at the characteristics of high water absorption rate and low strength of broken brick aggregate, a new method is proposed to improve the properties of recycled brick aggregate. In view of the fact that there is little research on recycled brick aggregate planting concrete in our country, there is no uniform and reasonable design method of mix ratio at present. The design idea of taking porosity as the main design parameter and strength as the secondary design parameter is put forward. The initial water-cement ratio test shows that when the water-cement ratio is 0.29-0.33, the cement mortar has certain fluidity and cohesion, the optimum water-cement ratio is 0.31, the target void ratio is 30 and the strength of regenerated brick aggregate is 4.92 MPa, which meets the requirements of engineering slope protection. In view of the characteristics of large void ratio and high water absorption of recycled brick aggregate, the mixture ratio can be calculated by saturated aggregate volume method. 2) after analyzing the source and form of alkali material in the pore of regenerated concrete, a comparative experiment was designed to reconstruct the alkalinity in the pore of regenerated brick aggregate by soaking in water and treating with FeSO4 solution. The results show that the PH in the pore of regenerated brick aggregate can be reduced to 9-10 by changing water every other day, and the PH in the pore of regenerated concrete treated with FeSO4 solution can reach 8-9, but the strength of the pore can be destroyed. Comprehensive consideration is that soaking with clear water is an effective method to improve the alkaline water environment in the pore of regenerated brick aggregate planting concrete. The purpose of reducing alkali can be achieved by prolonging the natural curing time in engineering. (3) according to the practical requirements of engineering application, this paper analyzes the kinds of planting matrix, grass seed and material selection principle, and studies the planting test of plant growth condition on regenerated brick aggregate planting concrete with different planting matrix. After the soil and seed were stirred evenly according to a certain proportion the plants could grow healthily on the ground by filling the inner voids in the regenerated brick aggregate planting concrete by grouting or stratified seeding together with the necessary maintenance and management.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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