乌江渡水电站所使用的混凝土砂石料,是采用机制的人工砂石料。砂石料从原材料的开采,以至到挖装运输、破碎筛洗和转运堆存等每一个环节,都有着程度不同的流失。细砂和石粉的流失,不仅污染了沿岸下游的水质,而且,由于流失细砂和石粉后的机制砂细度模数偏大(大于2.6±0.2毫米的规定),石粉含量 Concrete sand aggregate used by Wujiangdu Hydropower Station is artificial gravel material adopting the mechanism. Sand and gravel from the mining of raw materials, and even to the dredging transport, crushing sieve washing and transport and other aspects of storage, have varying degrees of loss. The loss of fine sand and stone powder not only pollutes the water quality downstream of the coast, but also because the modulus of fineness of the mechanism sand after the loss of fine sand and stone powder is too large (greater than 2.6 ± 0.2 mm), the content of stone powder