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介绍了构皮滩电站拱坝大体积混凝土配合比设计及混凝土力学性能、变形性能,对混凝土的抗冻性能、抗渗性能及热物理性能进行了测试,配制出了满足设计要求的拱坝混凝土配合比。通过大量强度试验,从强度的角度考虑,拱坝坝体C18025、C18030均可选用0.50的水胶比;综合考虑到混凝土28d极限拉伸的要求,粉煤灰掺量不可太大。限制常态混凝土最大粉煤灰掺量均在30%以下,按设计上限来掺粉煤灰可以保证混凝土的极限拉伸值等性能。混凝土单位用水量与粗细骨料粒形、级配、石粉含量、外加剂用量、坍落度等要求有关,在以上条件确定的情况下,主要取决于砂率和掺合料种类及掺量。合理的砂率可以使混凝土拌和物获得良好的和易性,并使硬化混凝土获得优良的综合性能。构皮滩电站大坝4级配常态混凝土单位用水量85kg/m3左右,最优砂率25%。
This paper introduces the mix proportion design of large volume concrete of arch dam of Goupitan Hydropower Station and the mechanical properties and deformation performance of concrete, tests the frost resistance, impermeability and thermophysical properties of the concrete, and prepares the arch dam concrete which meets the design requirements With the ratio. Through a large number of strength tests, from the point of view of strength, the water-cement ratio of 0.50 can be selected for C18025 and C18030 of arch dam. Considering the requirement of ultimate tensile of concrete 28d, the content of fly ash should not be too large. Restrictions on normal concrete maximum fly ash content are below 30%, according to the design of the upper limit to fly ash can guarantee the ultimate tensile properties such as concrete performance. Concrete unit water consumption and coarse and fine aggregate granularity, grading, stone powder content, admixture dosage, slump and other requirements, in the above conditions are determined, mainly depends on the sand rate and admixture types and dosage. Reasonable sand rate can make the concrete mix get good workability, and hardened concrete get excellent overall performance. Goupitan Hydropower Dam 4 with normal concrete unit water consumption about 85kg / m3, the best sand rate of 25%.