透水混凝土的力学性能及在护坡工程中的应用技术研究

发布时间：2018-08-31 16:42

【摘要】：随着我国经济的快速发展以及城市化进展水平的不断提高，人们愈来愈意识到环境保的护重要性，要求边坡防护工程不但要考虑其稳固性还要具有绿化功能。透水混凝土是一种多孔结构，具有一定的连续空隙，为植物的生长提供了可能。在此基础上开发出的植生型透水混凝土，由透水混凝土通过降低碱性、注入基质、铺设客土、播种植物并后期养护制得。然而这种混凝土在孔隙率能满足植物生长要求时，其强度往往又难以达到工程应用的条件。本文将透水混凝土与锚喷技术相结合，研究一种既能对岩质边坡进行整体防护又可起到绿化功能的新型生态护坡技术，即锚喷植生型透水混凝土生态护坡技术。在透水混凝土的配合比设计过程中，主要考虑其孔隙率和强度问题。锚喷混凝土的强度要求至少为20MPa，为了提供植生基材的填充空间和植被根系的生长空间，一般要求透水混凝土孔隙率要在20％以上。由于喷射管道直径的限制，喷射透水最大骨料粒径一般小于15mm。本文的研究内容就是要找出满足条件的透水混凝土配合比，并将其应用在护坡工程中。本文重点结合工程特点，借鉴相关领域生态防护和锚喷防护做法，对锚喷植生型透水混凝土在岩质边坡防护工程中的应用进行分析和探讨。主要完成了以下内容： 1、结合工程技术的需要，确定以骨料粒径和粉煤灰替代率为变量对透水混凝土进行分组配合比设计。即以骨料粒径（2.5~5mm、5~10mm、10~15mm）和粉煤灰替代率（0、10%、20%、40%）分组设计配合比并确定材料用量。 2、对不同配合比的试件进行抗压强度试验、抗折强度试验、孔隙率和透水系数测定。结果表明当骨料粒径为10~15mm，粉煤灰替代率为20%时，其28天抗压强度达到21.89MPa、孔隙率为21.3%，满足锚喷透水混凝土的技术要求。 3、根据实验数据分析表明随着骨料粒径的增大，透水性混凝土实测孔隙率变大，抗压和抗折强度增加，，透水系数增大；随着粉煤灰替代率的增加，透水性混凝土孔隙率减小，透水系数变小，而当粉煤灰替代率为20%时，抗压和抗折强度提高最多。 4、结合工程实例对应用锚喷植生混凝土技术对岩质边坡进行防护设计和优化了施工工艺。 5、通过数值模拟分析边坡防护前后的稳定性，验证锚喷植生混凝土技术的可行性。
[Abstract]:With the rapid development of economy and the improvement of urbanization level, people are becoming more and more aware of the importance of environmental protection, which requires slope protection not only to consider its stability but also to have greening function. Permeable concrete is a porous structure with certain continuous voids, which provides the possibility for plant growth. On this basis, the water permeable plant concrete was developed by reducing the alkalinity, injecting the matrix, laying the Hakka soil, sowing the plants and curing it later. However, when the porosity of the concrete can meet the requirements of plant growth, its strength is often difficult to meet the conditions of engineering application. In this paper, a new ecological slope protection technology, which can not only protect the rock slope as a whole but also play the greening function, is studied by combining the permeable concrete with the anchoring and shotcreting technology, that is, the ecological slope protection technology of the anchoring and shotcreting type permeable concrete. In the process of mix design of permeable concrete, porosity and strength are mainly considered. The strength of Anchorage shotcreting concrete is at least 20 MPA. In order to provide filling space for planting base material and growth space for vegetation root system, the porosity of permeable concrete is generally required to be above 20%. The maximum diameter of jet permeable aggregate is generally less than 15 mm. due to the limitation of injection pipe diameter. The research content of this paper is to find out the mixture ratio of permeable concrete which meets the conditions and apply it to slope protection project. Based on the characteristics of engineering, the application of water-permeable concrete in rock slope protection is analyzed and discussed in this paper based on the methods of ecological protection and Anchorage shotcrete protection in related fields. The main contents are as follows: 1. According to the need of engineering technology, the aggregate particle size and fly ash substitution rate are selected as variables to design the proportion of the permeable concrete. The mixture ratio was designed in groups of aggregate particle size (2.5 ~ 5 mm ~ 5 ~ 10 mm ~ 10 mm ~ 1015 mm) and fly ash substitution rate (0 ~ 10 ~ 10 ~ 20 ~ 40%) and the material dosage was determined. 2. The compressive strength test, flexural strength test, porosity and water permeability coefficient were tested on the specimens with different mix ratio. The results show that when the aggregate diameter is 10 ~ 15mm and the replacement ratio of fly ash is 20, the compressive strength and porosity are 21.89 MPA and 21.3 MPA respectively, which meet the technical requirements of water-permeable concrete. 3. According to the experimental data analysis, it is shown that with the increase of aggregate particle size, The measured porosity of permeable concrete increases, the compressive and flexural strength increases, and the permeability coefficient increases. With the increase of the replacement ratio of fly ash, the porosity of permeable concrete decreases and the permeability coefficient becomes smaller, but when the replacement ratio of fly ash is 20, The compressive and flexural strength are increased most. 4. Combined with engineering examples, the protection design and construction technology of rock slope with Anchorage and shotcrete technology are designed and optimized. 5. The slope is analyzed by numerical simulation Stability before and after protection, Verify the feasibility of Anchorage and shotcrete technology.
【学位授予单位】：武汉轻工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528

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