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毕业论文网 > 毕业论文 > 交通运输类 > 道路桥梁与渡河工程 > 正文

大体积混凝土水化热及应力分析毕业论文

 2021-10-24 03:10  

摘 要

大体积混凝土结构在地下工程特别是桥梁工程中得到了广泛的应用。大体积混凝土具有铸造量大、宽厚尺寸、水化热温度高、等特点。如果混凝土处于划定状态,如果内外温差过大或混凝土处于冷却期,温度收缩时会收缩,导致混凝土收缩。裂缝,裂缝会严重影响工程质量和进度,影响混凝土的耐久性和安全性,降低结构的水密度,降低结构的耐久性和耐久性因此具有重大的技术和经济意义,分析桥梁结构中混凝土结构水化热的温度场和电压场的空间分布,以防止温度裂缝的发生,提高工程的可靠性和耐久性。

同时,为了满足实际项目的需要,减少混凝土内外的温差,减少温度裂纹,确保混凝土结构的耐久性。需要考察混凝土水和热的影响对施工、运行过程的影响。混凝土的温度管理应该严格执行。发现由于大混凝土的水合热引起的温度裂纹问题对结构的稳定性有重要影响。同时,需要研究由于混凝土的水合热引起的温度应力和温度裂纹。

在大混凝土的固化过程中,混凝土的内部化学反应热使混凝土的自应力大于容许值并产生裂缝。对水合热场进行了理论分析,研究了降低混凝土水合热影响的技术方案,为项目顺利实施打下了良好的基础。本文的主要内容详细描述了温度场和应力的基本理论,并参考相关文献描述了温度场相关参数的理论重要性,讨论了混凝土的水合热与各参数之间的关系,并最终确定了相关参数。根据实际项目,Midasfea建立混凝土有限温度模型,计算混凝土水和热的温度场和应力场,将分析结果与测量数据进行比较,验证模型的合理性。基于计算结果的分析,总结了温度场和应力定律,并研究了混凝土水合热对裂纹的影响。讨论了混凝土中混凝土温度,水泥量,水泥种类,冷却和内部环境等影响混凝土水合热的因素。分析了混凝土屋顶的温度场和应力的不同因素,调查了结果的差异,最终实施了相应的温度控制措施。

关键词:桥梁,大体积承台,混凝土,水化热,温控措施

Abstract

Mass concrete structure has been widely used in underground engineering, especially bridge engineering. Mass concrete has the characteristics of large casting volume, wide and thick size, high hydration heat temperature, and easy occurrence of temperature cracks. If the concrete is in the demarcated state, if the temperature difference between the inside and outside is too large or the concrete is in the cooling period, the temperature will shrink when it shrinks, causing the concrete to shrink. Cracks, cracks will seriously affect the quality and progress of the project, affect the durability and safety of concrete, reduce the water density of the structure, reduce the durability and durability of the structure.So, it has great technical and economic significance. The spatial distribution of the temperature field and voltage field of the heat to prevent the occurrence of temperature cracks and improve the reliability and durability of the project.

At the moment, to meet the needs of the actual project, reduce the temperature difference between the inside and outside of the concrete, reduce the temperature cracks, and ensure the durability of the concrete structure. The impact of concrete water and heat on construction and operation needs to be investigated. Concrete temperature management should be strictly implemented. It is found that the temperature cracking problem caused by the hydration heat of large concrete has an important effect on the stability of the structure. At the same time, it is necessary to study the temperature stress and temperature cracks caused by the hydration heat of concrete.

During the curing process of large concrete, the internal chemical reaction heat of the concrete makes the self-stress of the concrete greater than the allowable value and generates cracks. The theoretical analysis of the hydration heat field was carried out, and the technical scheme for reducing the influence of concrete hydration heat was studied, which laid a good foundation for the smooth implementation of the project. The main content of this article describes the basic theory of temperature field and stress in detail, and describes the theoretical importance of temperature field related parameters with reference to related literature, discusses the relationship between the hydration heat of concrete and each parameter, and finally determines the related parameters . According to the actual project, Midasfea establishes a finite temperature model of concrete, calculates the temperature and stress fields of concrete water and heat, and compares the analysis results with the measured data to verify the rationality of the model. Based on the analysis of the calculation results, the temperature field, and the influence of the hydration heat of the concrete on the crack is studied. The factors influencing the hydration heat of concrete, such as the temperature of concrete in concrete, the amount of cement, the type of cement, cooling and internal environment are discussed. The different factors of the temperature field and stress of the concrete roof were analyzed, the difference of the results was investigated, and the corresponding temperature control measures were finally implemented.

Key words:Bridges, large-volume platforms, concrete, hydration heat,Temperature control measures

目录

第 1章 绪论

1.1研究背景

1.2本文研究意义和拟解决问题

第2 章 大体积混凝土承台模型的建立和结果分析

2.1工程概况

2.2有限元模型的建立

2.3温度场及温度应力计算结果

第 3章大体积承台施工参数分析及温控建议

3.1混凝土入模温度的影响

3.2外部保温材料的影响

3.3温控建议

第 4章结论与展望

4.1结论

4.2展望

致谢

参考文献

第1 章 绪论

    1. 研究背景

近几十年来,桥梁行业发展迅速,对桥梁抗拉能力的要求越来越高这里。在桥梁的施工越来越多,如大体积混凝土仓库,座墩零块锚地在。其他与使用低温混凝土的大型水工建筑物相比,桥梁的大型混凝土构件使用普通强度或高强度混凝土,满足强度和耐久性要求在建筑产生水泥的水化反应很多水化墙客房提高混凝土温度,水化反应速率也变得明显加速。之后在一两天内注入大部分水化热已发布。到期混凝土的导热系数极低,收集了构件内的湿热,难以分布,构件内外温差大,如果拉伸应力超过相应年龄段的容许拉伸强度,则会导

致温度裂缝,并损害部件的性能。

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