公路用预拌混凝土早期力学特性分析

Analysis of Mechanical Properties of Concrete in Early Stage for Highway

在混凝土抗拉力学性能分析中,强度和极限拉伸是两项极为重要的指标。目前,关于极限拉伸的试验研究暂无明确统一的方法,同时轴心受拉试验有着一定程度的困难,导致其试验结果较为离散。为了使公路用预拌混凝土的早期拉伸变形值、轴心抗拉与劈裂强度两者之间的关系能够更加准确,将公路用混凝土的轴心受拉试验装置进行优化设计,有效解决了混凝土试件对中时存在的困难,并以3个强度等级的预拌混凝土为研究对象,对其进行1个龄期(72、168、336、672 h)的试验,分别得出混凝土在龄期内其极限拉伸值、强度、轴拉弹性模量三者的发展规律,同时通过对混凝土的极限拉伸值进行推理,得出其估算公式。试验结果表明:当龄期增大时,混凝土的轴拉与劈裂强度之比逐渐变小;混凝土的拉压关系基本满足规范公式要求。

In the analysis of tensile strength of concrete,the strength and the ultimate tension are two important indexes. At present,about ultimate tensile test of no clear unified method and axial tensile test with a certain degree of difficulty,cause the test result is discrete. In order to make the road ready mixed concrete early age tensile deformation,axial tensile and splitting the relationship between strength can more accurately,this paper will be of the road concrete under axial by tensile test device for optimization design,effective solution to the concrete test pieces on it is difficult and three strength grades of ready mixed concrete as the research object,the were 1 age(72 h and 168 h,336 h,672 h) test,obtained respectively concrete during the age of the ultimate tensile value,strength,the development law of axial tensile elastic modulus is,at the same time,through the limit of concrete tensile value reasoning,obtained the formula of. The experimental results show that the ratio of axial tension and splitting strength of concrete gradually becomes smaller when the age is increased,and the tension and compression of concrete meets the requirement of the standard formula.