大坝混凝土强度参数的统计分析

Statistical analysis of dam concrete strength parameters

抗拉强度和抗压强度是常用的两种混凝土强度指标。抗拉强度可以采用轴向拉伸试验、弯曲试验和劈裂抗拉强度试验测定,抗压强度由立方体抗压强度试验测定。大坝混凝土的材料试验常采用全级配大试件和湿筛小试件两种形式。不同尺寸试件、不同类型试验的混凝土强度指标存在一定的统计关系。本文结合实际混凝土大坝工程,对全级配混凝土及湿筛混凝土的各种静、动强度试验结果进行总结,研究混凝土强度的率效应、尺寸效应,分析各强度指标之间的定量关系,并与国内、外规范及相关成果进行比较,为实际工程提供可参考的依据。

Tensile strength and compressive strength are common strength indexes of concrete. Tensile strength can be measured by direct tensile test, three point bending test, and tensile splitting strength test; and compressive strength measured by cube compressive strength test. Fully-graded large specimens and wet-screened small specimens are typical forms used in dam concrete material test. Certain statistical relationships exist between strength indexes of concrete specimens with different sizes under tests of different types. This paper summarizes static and dynamic test results of fully-graded concrete and wet-screened concrete considering concrete materials in actual dam projects, including examination on the rate effect and size effect of concrete strength and analysis on the quantitative relationships between different strength indexes. The results are compared with previous studies in literature and they would provide significant information to design of actual projects.