大坝全级配与湿筛二级配混凝土力学性能试验研究及统计分析

Experimental Study and Statistic Analysis on Mechanical Properties of Fully-graded and Wet-screened Two-graded Concrete in Dams

以某大坝工程为研究对象,采用现场浇注成型的试件进行全级配和湿筛二级配混凝土强度试验。试验结果表明,在28 d、90 d、180 d三个龄期时全级配与湿筛二级配混凝土的抗压强度比值最大,劈拉强度比值次之,弹性模量比值最小。而后,结合其它大坝混凝土强度实测试验数据,统计分析了全级配与湿筛二级配混凝土的强度比值关系。分析结果表明,全级配和湿筛二级配混凝土强度比值均服从正态分布,由此分别给出了具有95%保证率的全级配与湿筛二级配混凝土抗压、劈拉强度比值,从而可通过湿筛二级配混凝土强度预测全级配混凝土强度。

Taking a dam for research object ,the cast-in-situ specimens are tested to study the strength of fully-graded and wet-screened two-graded concrete .The experimental results show that on the concrete with the ages of 28 ,90 and 180 days ,the ratio of the compressive strength of fully-graded and wet-screened two-graded concrete is largest ,and the splitting-tensile strength ratio is secondary ,while the elastic modulus ratio is lowest .Furthermore ,the relationship be-tween the strength ratio values for fully-graded and wet-screened two-graded concrete is analyzed statistically .It is found that their ratio values of compressive strength and splitting-tensile strength all follow normal distribution .Based on the distribution ,the compressive and splitting tensile strength ratios of fully-graded and wet-screened two-graded concrete with a 95% performance assurance can be calculated and obtained separately .Thereby ,the strength of fully-graded con-crete can be estimated by testing the strength of wet-screened two-graded concrete .