【作者】 米永刚；

【导师】 谷拴成；

【作者基本信息】 西安科技大学 ， 结构工程， 2008， 硕士

【摘要】 大体积混凝土裂缝是困扰建筑业多年的质量通病,如裂缝较多、较深,将直接影响结构安全。这些大体积混凝土结构,由于外荷载引起裂缝的可能性较小,而由水泥水化过程中释放的水化热引起的温度变化和混凝土收缩产生的温度应力是产生裂缝的主要原因,是在大体积混凝土结构施工中要解决的重要问题。在大体积混凝土中,温度应力及温度控制具有重要意义,这主要是由于两方面的原因:首先,在施工中混凝土常常出现温度裂缝,影响到结构的整体性和耐久性;其次,在运转过程中,温度变化对结构的应力状态具有显著的不容忽视的影响。我们遇到的主要是施工中的温度裂缝。本文主要从以下几方面进行了深入的研究和探讨:(1)大体积混凝土裂缝产生的机理及原因分析;(2)从组成原材料材质:水泥品质、沙石颗粒级配、外加剂掺量、粉煤灰掺量等对西安市田王S10工程C20混凝土配比进行了优化;(3)对大体积混凝土温度进行预测、并对大体积混凝土温度场进行理论分析计算、大体积混凝土温度应力计算、大体积混凝土测温系统;(4)通过配比优化和温度应力计算,得出混凝土中粉煤灰最佳产量25%,以及不产生裂缝须保证混凝土内外温差小于12℃。更多还原

【Abstract】 Massive Concrete cracks were troubled years of construction quality defects, such as cracks moredeeper, it will directly affect the structural safety. These massive concrete structure, cracks due to the load because of the possibility of smaller, and by the hydration of cement hydration process of the release of heat and temperature changes caused by the shrinkage of concrete shrinkage stress and thermal stress is the main reason for the cracks, Coagulation in large volume on the construction of the structure to solve the important issues. In the mass concrete, temperature stress and temperature control is of great significance, mainly in the mountains in two ways. First, in the construction of concrete often cracks temperature affect structural integrity and durability. Secondly, in the operation of the temperature change on the structure of the stress state of the significant impact that should not be overlooked. We encountered mainly in the construction of the temperature cracks. This paper mainly from the following aspects carried out in-depth research and study:(1)Temperature of massive concrete cracks and the reasons for the selection of analysis;(2)Material from the composition of raw materials: the quality of cement, sand particle size distribution, the amount of additives, such as fly ash content concrete to the project C20 ratio has been optimized;(3)Mass concrete temperature control measures: mass concrete temperature is forecast, the temperature stress of mass concrete, mass concrete temperature measurement system;(4)through the ratio of optimization and thermal stress, that the best fly ash in concrete production by 25%, and the need to ensure that no cracks in concrete and outside temperature difference of less than 12℃.更多还原