小湾水电站双曲拱坝混凝土性能研究

Study on the Properties of Concrete for Arch Dam of Xiaowan Hydropower Station

介绍了小湾水电站双曲拱坝混凝土原材料、主要设计参数及配合比;基于湿筛二级配混凝土坍落度和含气量的损失率以及实际混凝土拌和物的坍落度、含气量及出机口温度,分析了混凝土拌和物的性能;通过湿筛二级配混凝土和全级配混凝土性能试验,研究了抗压强度、劈拉强度、轴拉强度和抗弯强度等主要力学性能,以及静压弹性模量、轴拉弹性模量、极限拉伸值和自生体积变形等性能,同时还研究了混凝土抗渗、抗冻等耐久性参数以及绝热温升等热学参数。研究结果表明,小湾水电站双曲拱坝混凝土选用的原材料较优;混凝土配合比设计较先进;大坝混凝土具有"高强度、高极拉、低热、中弹模、不收缩"的性能。

The raw materials, design requirements and mixing proportions of dam concrete for the arch dam of Xiaowan Hydropower Project are introduced. Based on the slump and air content loss ratios of wet screened concrete with a maximum particle size of 40mm as well as the slump, air content and concrete temperature at mixing plant, the proper- ties of concrete mixture are analyzed. Performance tests of wet screened concrete and dam concrete are carried out, which includes mechanical performances such as compressive strength, splitting tensile strength, axial tensile strength and flexural strength, and also deformation properties such as static elastic modulus, axial tensile elastic modulus, ulti- mate tensile extensibility and autogenous shrinkage. In addition, experiments on durability performance of anti-seepage and frost resistance as well as adiabatic temperature rise are also completed. The test results indicate that the suggested concrete raw materials and mix proportions are reasonable and practicable. The high performance properties of dam concrete, such as high strength, high ultimate tension, low heat, medium elastic modulus and little shrinkage, have been realized.