【作者】 李跃；

【导师】 霍凯成； 水中和；

【作者基本信息】 武汉理工大学 ， 结构工程， 2004， 硕士

【摘要】 大体积混凝土由于其体积庞大，一次性混凝土浇注量大，工程条件复杂，因而若施工措施控制不力，极易产生各种混凝土结构裂缝，轻者会影响混凝土的耐久性，重者还会严重影响混凝土的力学性能。因此，对大体积混凝土裂缝进行有效的预防，成为工程界普遍关注的课题。由于大体积混凝土应用条件的多样性和水泥混凝土体系自身的复杂性，大体积混凝土的开裂问题还大量存在。这些现实问题要求我们对混凝土的开裂机理、裂缝发展、评价体系和控制措施进行更加深入的研究。 本文在总结已有温控防裂成果的基础上从混凝土的原材料、配合比、外加剂、施工工艺等宏观方面以及混凝土的微观结构方面研究大体积混凝土的温度应力、开裂原因和裂缝控制措施。综合考虑了温度应力与混凝土的干缩、自收缩、温度收缩和塑性收缩所产生的应力叠加对混凝土开裂的影响，提出大体积混凝土裂缝控制的基本原则，并将新的智能混凝土技术应用于混凝土结构的温度自监控与损伤自诊断研究，提出大体积混凝土温控与防裂的新方法。 在混凝土的早期开裂研究方面，通过间接评价方法(水化热试验、绝热温升试验、收缩试验)和直接评价方法(环约束试验、轴约束试验)对不同混凝土的抗裂性能进行了试验研究，并详细介绍了国内最新研发的温度—应力试验机，通过对不同的混凝土拌合物进行试验量化分析，研究了混凝土内部温度场、温度应力、塑性强度和弹性模量等参量发展变化的规律，分析了影响混凝土早期开裂的诸多因素，提出基于温度—应力试验的混凝土开裂评价指标：第二零应力温度＜40℃，应力储备＞35％，开裂温度＜14℃。更多还原

【Abstract】 Mass concrete is easy to crack if constructed improperly, because of its huge volume and complicated construction condition. And the cracking will either affect the durability of the concrete structure, or even influence the mechanics performance of the concrete. So avoiding the mass concrete from cracking has drawn the attention of the engineering field of the whole world. As the variety of mass concrete application and its complexity, the cracking of mass concrete is occurring at large. These problems request us to do more researches on cracking mechanism, cracking development, assessment criteria and cracking control methods.Based on the former fruits of temperature control and cracking prevention, the temperature stress, cracking causes and cracking control measures are studied from the macro-aspects such as: raw materials, mix ratio, additives and construction technology , and also from the micro-structure of concrete. The effect of the combination of temperature stress and the multi-stress caused by the dry shrinkage, self-shrinkage, temperature shrinkage and plastic shrinkage is considered, and the basic cracking control measures are concluded. And new temperature and cracking control method is created , which applies the carbon fiber reinforced concrete techniques into the temperature and cracking self-monitoring.On the early cracking research, the indirect assessment methods such as: hydration test, isolation temperature rise test and shrinkage test, and direct assessment methods such as: ring restraint test and single axis restraint test are studied to contrast the different cracking performances of different concrete mixtures in this paper. The causes affect the early cracking of concrete are analyzed here and the cracking assessment criteria based on the temperature-stress test is concluded: temperature of the second zero stress<40℃, stress storage>35% and cracking temperature <14℃更多还原