隧道二次衬砌防渗混凝土制备及性能研究
发布时间：2019-03-05 19:19
【摘要】：西部地区气候条件严酷、水文地质条件复杂，隧道衬砌混凝土易出现开裂、渗漏、冻融及侵蚀破坏等耐久性问题。混凝土抗渗性是混凝土耐久性的一个重要方面，因此本文从混凝土抗渗性能方面出发，结合西部地区特定的气候环境与水文地质条件，提出满足隧道二次衬砌各项性能要求的混凝土配合比设计思路，解决隧道衬砌结构的渗漏问题。 通过对石灰石粉、粉煤灰单掺和二者复掺对水泥砂浆的基本性能影响研究，发现少量石灰石粉可提高水泥砂浆流动性及早期强度，粉煤灰可提高水泥砂浆的流动性、后期强度、能抑制收缩；两者进行合理的复掺可提高水泥砂浆的流动性、降低收缩，虽然早期强度略有降低，但对后期强度有积极的影响。 通过对影响混凝土强度及抗渗性能的各个因素研究，采用正交试验选定影响混凝土强度及抗渗性能的主要四个因素进行研究，结果表明：在选定的因素水平范围水胶比是影响混凝土抗渗性能最显著的因素，粉煤灰掺量、石灰石粉掺量影响较小，而砂率对混凝土抗渗性能影响不显著。四个因素对混凝土抗渗性能影响的程度是水胶比㧐石灰石粉掺量㧐粉煤灰掺量㧐砂率。根据隧道二衬混凝土的特点提出其配合比设计思路，采用低水胶比并加入大掺量的掺合料及高效减水剂来平衡混凝土强度、流动性和抗渗性三者的关系。通过试验对比优选出两组抗渗性能优异的混凝土，其水胶比分别为0.3、0.38，掺合料总量分别为50%、30%。再通过试验优选出这两组混凝土配合比的最佳用水量，比选出防渗性能良好的外加剂FSL，最终优化出两组符合隧道二次衬砌防渗混凝土配合比，对两组配合比进行抗渗等级的试验，抗渗等级均达到P12以上，为隧道二次衬砌混凝土配合比设计提供参考。 通过分析研究证明水胶比是影响混凝土抗渗性能最重要的因素，水胶比越低抗渗性能越好，，配制防渗混凝土时，在满足工程其他性能的前提下建议选择低水胶比；适量的粉煤灰和石灰石粉可以降低水泥基材料收缩，提高混凝土的抗渗性能，应用在隧道二次衬砌混凝土工程中可满足施工性能及力学要求，一定程度上提高了隧道二次衬砌混凝土抗渗问题，且粉煤灰和石灰石粉替代水泥可以降低工程成本，具有一定的经济效益。
[Abstract]:The climatic conditions in the western region are severe, the hydrogeological conditions are complex, and the tunnel lining concrete is prone to cracking, leakage, freezing and thawing, erosion and other durability problems. The impermeability of concrete is an important aspect of the durability of concrete. Therefore, this paper starts from the aspect of concrete impermeability and combines the specific climatic environment and hydrogeological conditions in the western region. In order to solve the leakage problem of tunnel lining structure, the design idea of concrete mix ratio which meets the performance requirements of secondary lining of tunnel is put forward. Through the study of the influence of lime powder, fly ash and both on the basic properties of cement mortar, it is found that a small amount of limestone powder can improve the fluidity and early strength of cement mortar, and fly ash can improve the fluidity of cement mortar and the later strength of cement mortar. It can inhibit contraction; It can improve the fluidity of cement mortar and decrease the shrinkage of cement mortar. Although the early strength decreases a little, it has a positive effect on the later strength of cement mortar. Through the study of the factors affecting the strength and impermeability of concrete, the main four factors which affect the strength and impermeability of concrete are selected by orthogonal test, and the main factors affecting the strength and impermeability of concrete are studied. The results show that the ratio of water to glue is the most significant factor affecting the impermeability of concrete in the range of the selected factors. The content of fly ash and limestone powder have little effect on the impermeability of concrete, while the sand ratio has no significant effect on the impermeability of concrete. The effect of the four factors on the impermeability of concrete is the ratio of water to binder? Lime powder? Fly ash content? Sand rate According to the characteristics of tunnel second lining concrete, the design idea of its mix ratio is put forward. The relationship among strength, fluidity and impermeability of concrete is balanced by using low water binder ratio, adding large amount of admixture and superplasticizer to balance the relationship among the strength, fluidity and impermeability of concrete. Two groups of concrete with excellent impermeability were selected by experiment. The ratio of water to binder was 0.3 and 0.38 respectively. The total amount of admixture was 50% and 30% respectively. Then the optimum water consumption of the two groups of concrete mix ratio was optimized through the test, and finally two groups of anti-seepage concrete mix ratio were optimized according to the secondary lining of tunnel by selecting the addition agent FSL, with good anti-seepage performance. The impermeability grade of the two groups is above P12, which provides a reference for the design of the mixture ratio of the secondary lining concrete in the tunnel. Through the analysis and research, it is proved that the water-binder ratio is the most important factor affecting the impermeability of concrete. The lower the water-binder ratio, the better the impermeability. In the preparation of anti-seepage concrete, it is suggested to choose the low water-binder ratio under the premise of satisfying the other properties of the project. Appropriate amount of fly ash and limestone powder can reduce the shrinkage of cement-based materials and improve the impermeability of concrete, which can meet the requirements of construction performance and mechanics in the secondary lining concrete engineering of tunnel. The impermeability problem of tunnel secondary lining concrete has been improved to a certain extent, and the replacement of fly ash and limestone powder for cement can reduce the engineering cost and has certain economic benefits.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U454
本文编号：2435204
[Abstract]:The climatic conditions in the western region are severe, the hydrogeological conditions are complex, and the tunnel lining concrete is prone to cracking, leakage, freezing and thawing, erosion and other durability problems. The impermeability of concrete is an important aspect of the durability of concrete. Therefore, this paper starts from the aspect of concrete impermeability and combines the specific climatic environment and hydrogeological conditions in the western region. In order to solve the leakage problem of tunnel lining structure, the design idea of concrete mix ratio which meets the performance requirements of secondary lining of tunnel is put forward. Through the study of the influence of lime powder, fly ash and both on the basic properties of cement mortar, it is found that a small amount of limestone powder can improve the fluidity and early strength of cement mortar, and fly ash can improve the fluidity of cement mortar and the later strength of cement mortar. It can inhibit contraction; It can improve the fluidity of cement mortar and decrease the shrinkage of cement mortar. Although the early strength decreases a little, it has a positive effect on the later strength of cement mortar. Through the study of the factors affecting the strength and impermeability of concrete, the main four factors which affect the strength and impermeability of concrete are selected by orthogonal test, and the main factors affecting the strength and impermeability of concrete are studied. The results show that the ratio of water to glue is the most significant factor affecting the impermeability of concrete in the range of the selected factors. The content of fly ash and limestone powder have little effect on the impermeability of concrete, while the sand ratio has no significant effect on the impermeability of concrete. The effect of the four factors on the impermeability of concrete is the ratio of water to binder? Lime powder? Fly ash content? Sand rate According to the characteristics of tunnel second lining concrete, the design idea of its mix ratio is put forward. The relationship among strength, fluidity and impermeability of concrete is balanced by using low water binder ratio, adding large amount of admixture and superplasticizer to balance the relationship among the strength, fluidity and impermeability of concrete. Two groups of concrete with excellent impermeability were selected by experiment. The ratio of water to binder was 0.3 and 0.38 respectively. The total amount of admixture was 50% and 30% respectively. Then the optimum water consumption of the two groups of concrete mix ratio was optimized through the test, and finally two groups of anti-seepage concrete mix ratio were optimized according to the secondary lining of tunnel by selecting the addition agent FSL, with good anti-seepage performance. The impermeability grade of the two groups is above P12, which provides a reference for the design of the mixture ratio of the secondary lining concrete in the tunnel. Through the analysis and research, it is proved that the water-binder ratio is the most important factor affecting the impermeability of concrete. The lower the water-binder ratio, the better the impermeability. In the preparation of anti-seepage concrete, it is suggested to choose the low water-binder ratio under the premise of satisfying the other properties of the project. Appropriate amount of fly ash and limestone powder can reduce the shrinkage of cement-based materials and improve the impermeability of concrete, which can meet the requirements of construction performance and mechanics in the secondary lining concrete engineering of tunnel. The impermeability problem of tunnel secondary lining concrete has been improved to a certain extent, and the replacement of fly ash and limestone powder for cement can reduce the engineering cost and has certain economic benefits.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U454
【参考文献】
相关期刊论文 前10条
1 牛丽坤;谢友均;龙广成;;粉煤灰掺量与砂浆强度之间相互关系的影响研究[J];粉煤灰;2006年01期
2 邓世汉;张杰;唐儆泽;许碧莞;;纤维对混凝土抗渗性能及硬化水泥浆体孔结构的影响[J];港工技术;2007年03期
3 龙广成;谢友均;牛丽坤;;砂浆中粉煤灰的最佳掺量[J];硅酸盐学报;2006年06期
4 颜承越;;混凝土渗透系数与抗渗标号的换算[J];混凝土;1993年03期
5 张驰,袁晓露,周世华;矿物掺合料与高效减水剂对水泥基材料流变性能的影响[J];混凝土;2004年09期
6 杨华山;方坤河;涂胜金;杨惠芬;;石灰石粉在水泥基材料中的作用及其机理[J];混凝土;2006年06期
7 刘行;殷素红;李铁锋;文梓芸;史海欧;刘健美;;水泥基渗透结晶型防水剂在地铁应用的试验研究[J];混凝土;2007年04期
8 陆晗;王卫仑;;膨胀剂对混凝土渗透性的影响[J];混凝土;2010年04期
9 杨玉红;李悦;杜修力;;自密实混凝土早期自收缩及微观孔结构研究[J];建筑材料学报;2010年05期
10 周艳;杜应吉;;大掺量粉煤灰混凝土的干燥收缩性能研究[J];人民黄河;2010年05期
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