大坝全级配与湿筛二级配混凝土基本力学性能试验研究及统计分析

发布时间：2018-08-18 17:26

【摘要】：近年来,水电科技工作者对全级配与湿筛二级配混凝土强度比值进行了大量的研究,两者的抗压强度比值约为0.7-0.9,抗拉强度比值约为0.5-0.7,全级配混凝土强度小于湿筛二级配混凝土强度。目前,全级配和湿筛二级配混凝土比值尚无统一结论。因此,直接使用湿筛法成型的小试件所测得的力学指标,不能真实反映全级配大坝混凝土的力学性能。基于此,本文以溪洛渡大坝工程为研究对象,采用现场浇筑成型的试件在龄期为28d、90d、180d时进行全级配与湿筛二级配混凝土的基本力学性能试验,将所得到的试验结果与其它大坝混凝土强度实测试验数据相结合,统计分析了全级配与湿筛二级配混凝土的强度比值关系。主要完内容如下： 1、对溪洛渡大坝施工现场所用材料进行全级配和湿筛二级配混凝土的抗压强度、抗拉强度、弹性模量试验。结果表明,这三个参数随龄期增长而增加。全级配和湿筛二级配混凝土28d、90d、180d三个龄期的抗压强度比值最大,抗拉强度比值次之,弹性模量比值最小； 2、统计前人对大坝全级配与湿筛二级配混凝土抗压强度、抗拉强度比值数据,采用拟合优度k-s检验方法对所统计数据和本试验所得到数据进行非参数检验,发现抗压强度、抗拉强度比值服从正态分布,抗压强度比值k-s检验正态分布的显著性概率为80.6%,抗拉强度比值k-s检验正态分布的显著性概率为42.1%；全级配与湿筛二级配混凝土抗压强度比值均值为0.840,抗拉强度比值均值为0.734。具有95%保证率的全级配与湿筛二级配混凝土抗压强度和抗拉强度比值分别为0.767、0.562,为全级配混凝土的强度试验和工程应用提供了参考。
[Abstract]:In recent years, a great deal of research has been done on the strength ratio of the whole grade concrete to the second grade concrete of the wet screen by the water and electricity science and technology workers. The ratio of compressive strength and tensile strength is about 0.7-0.9and the ratio of tensile strength is about 0.5-0.7.The strength of full-graded concrete is less than that of two-stage concrete with wet screen. At present, there is no uniform conclusion on the ratio of whole grade concrete and wet screen concrete. Therefore, the mechanical properties of the whole gradation dam concrete can not be truly reflected by the mechanical indexes measured by the small specimen formed by the wet screening method. Based on this, taking Xiluodu dam project as the research object, the basic mechanical properties of concrete with full gradation and wet screen secondary distribution were tested when the age of the specimen was 28 d ~ 90 d ~ 180 d. Combining the experimental results with the measured data of other dam concrete strength, the relationship between the strength ratio of full gradation concrete and wet sieve secondary concrete is analyzed statistically. The main contents are as follows: 1. The compressive strength, tensile strength and elastic modulus of the materials used in the construction site of Xiluodu dam are tested with full gradation and wet sieve secondary distribution concrete. The results show that these three parameters increase with age. The ratio of compressive strength to tensile strength is the largest, the ratio of tensile strength to elastic modulus is the least, and the compressive strength of concrete with full gradation of dam and second stage of wet sieve is the lowest in three ages of 28d ~ 90d ~ 180d. 2, the statistical results show that the compressive strength of concrete with full gradation of dam and second stage of wet sieve is the lowest. According to the data of tensile strength ratio, the non-parametric test of the statistical data and the data obtained in this experiment is carried out by using the method of goodness of fit k-s test, and it is found that the ratio of compressive strength and tensile strength is normally distributed. The significant probability of the normal distribution tested by the compressive strength ratio (k-s) is 80.6, the significant probability of the tensile strength ratio (k-s) to the normal distribution is 42.1%, the mean value of the full gradation and wet sieve secondary distribution concrete compressive strength ratio is 0.840, and the average tensile strength ratio is 0.734. The ratio of compressive strength and tensile strength of full-gradation concrete to wet-sieve concrete with 95% guarantee rate is 0.7670.562 respectively, which provides a reference for strength test and engineering application of full-graded concrete.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV431

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