机制砂混凝土在冻融循环条件下的强度和耐久性能 论文.doc

毕业设计说明书 机制砂混凝土在冻融循环条件下 的强度和耐久性能 学 院： 建筑工程学院 专 业： 土木工程 学生姓名： 学 号： 指导教师： 2012 年 06月 摘 要 随着混凝土结构工程的发展，机制砂混凝土对施工性能和强度的要求越来越高，对耐久性越来越重视。另一方面低温环境可能造成建筑结构的破坏,致使其需要简单修复或进行加固,甚至需要拆掉重建。本课题意在通过一系列调查和试验得到机制砂混凝土在冻融下的强度和耐久性数据，为以后的研究积累经验。 本文通过试验研究和理论分析，主要完成了以下工作: l、根据实验要求配制了150mm*150mm*150mm的混凝土试件，在养护28天后并利用这些混凝土试件进行冻融循环试验，抗冻等级分别为F0、F5、F10、F15、F20、F25，并对试件进行耐久性试验。 2、对试件进行耐压强度、弹性模量、变形实验，观察试件的破坏形态，得到混凝土试件的强度损失、弹性模量损失等。 试验分析了机制砂混凝土试件强度减低幅度与抗冻等级和酸碱的关系，得到了混凝土在不同抗冻等级和酸碱下混凝土力学性能的退化模型。本文通过冻融后机制砂混凝土的力学特性进行试验研究，阐述了冻融后机制砂混凝土的强度、变形和弹性模量与抗冻等级的关系，论证了混凝土经受冻融后的剩余强度和变形特性，得出了机制砂混凝土在冻融影响下强度降低，耐久性明显下降等特征。 关键词：机制砂混凝土；冻融；强度；耐久性能 Abstract With the development of concrete structures, the sand concrete, which has a high demand for construction performance and strength and more and more emphasis on durability. On the other hand, low-temperature environment may cause structural damage, resulting in a need for a simple repair or reinforce, or even need to tear down reconstruction. This topic is intended to get through a series of investigations and trials to get the strength and durability data of sand concrete which is under freeze-thaw. In this paper, with the experimental study and theoretical analysis, mainly to complete the following work: 1、According to the experiment made by the requirements of the 150mm * 150mm * 150mm of concrete specimens, after 28 days in the conservation and use of these concrete specimens to room temperature and freeze-thaw cycle test, the frost-resisting grade of F0,F10,F15,F30,and test pieces of the durability test. 2、To test the compressive strength, the modulus of elasticity and the deformation of the specimens, observe the failure pattern of the specimens, then gain the strength loss and the loss of elastic modulus of concrete specimens,. With the results of low-temperature durability test, analyze the relationship between the strength decrease of the s