掺有乳化沥青的大体积混凝土的裂缝控制机理及工程应用

发布时间：2018-01-16 23:02

本文关键词：掺有乳化沥青的大体积混凝土的裂缝控制机理及工程应用　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着土木工程的发展,大体积混凝土在大坝、桥墩、承台等大型基础方面应用越来越多。大体积在浇筑完成后内部会产生大量的水化热,导致混凝土内部温度巨升,再加上混凝土自身散热效果不好,从而内外形成温差。进而产生温度应力。又因为混凝土是抗拉能力偏小的脆性材料,由此容易开裂。在现有工程案例中,各类大体积混凝土结构开裂状况严重,给工程造成了安全隐患。针对大体积混凝土温度裂缝问题,论文从改变材料性质着手,提出在大体积混凝土中掺入乳化沥青,有效地改善了大体积混凝土的各项力学性能,提高了大体积混凝土的抗裂能力。(1)将制备好的乳化沥青作为掺合材料,通过无侧限抗压试验,马歇尔试验等试验对比,得出各成分的用量对大体积混凝土性能的影响规律,从而确定了水、水泥、集料、乳化沥青、减水剂等成分的最佳用量,得出了乳化沥青的混凝土的最佳配合比。(2)对掺有不同用量的乳化沥青的拌合料浆体凝结后的不同龄期进行扫描电镜观察,观察掺有乳化沥青的混凝土拌合料在不同龄期的扫描电镜中各种图片,从而分析掺有不同用量的乳化沥青的混凝土随龄期变化的运动趋势,更加深入掌握掺有乳化沥青的大体积混凝土的抗裂性能。(3)分析大体积混凝土结构的裂缝形成机理,计算了大体积混凝土结构浇筑完成后的三个阶段温度场、应力场。(4)将掺有乳化沥青的混凝土应用到实际工程,实践结果表明:掺有乳化沥青的大体积混凝土抗裂效果明显,理论计算结果与实际工程应用效果基本吻合。同时通过工程实践,总结出掺有乳化沥青混凝土应用注意事项。
[Abstract]:With the rapid development of civil engineering, bridge mass concrete in dams, caps and other large-scale infrastructure applications. More and more large volume in the pouring is completed inside will produce a lot of heat of hydration, resulting in huge concrete internal temperature rise, coupled with their own concrete cooling effect is not good, which is formed inside and outside temperature and temperature. Force. Because concrete is a brittle material tensile capacity is too small, it is easy to crack. In the existing engineering cases, all kinds of large volume concrete structure cracking condition is serious, resulting in a safety hazard to the project. For large volume concrete temperature crack problem, the change from material properties to put in the large volume of concrete mixed with emulsion asphalt, effectively improve the mechanical properties of concrete, improve the crack resistance capability of concrete. (1) the prepared emulsion asphalt as blending material The material, through the unconfined compression test, compared with Marshall test, the influence of the composition of the content on the properties of mass concrete, so as to determine the water, cement, aggregate, asphalt emulsion, optimum dosage of water reducing agent and other components, the optimum mix concrete of emulsified asphalt ratio (. 2) scanning electron microscope at different ages mix slurry with different amount of emulsified asphalt mixed condensation of concrete mixed with emulsified asphalt mixture was observed in scanning electron microscope at different ages in the picture, so as to analyze the concrete with different amount of emulsified asphalt with the movement trend of the age change and the anti cracking performance of more in-depth grasp of mass concrete mixed with emulsified asphalt. (3) analysis of the large scale concrete structure crack formation mechanism, calculation of the three stages of temperature field of mass concrete structure after concreting, Stress field. (4) the application of emulsified asphalt mixture concrete to the actual project, the practice result shows that mixed with emulsified asphalt concrete anti cracking effect is obvious, the theoretical calculation result and the actual project application basically. At the same time through the engineering practice, summed up the application of emulsified asphalt concrete mixed with the matters needing attention.

【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】：TU755.7

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