关于体积法计算混凝土配合比中原材料密度的问题

About density of raw materials for calculating mix proportion of concrete by volume method

接受新疆农业大学葛毅雄教授的意见,《关于混凝土配合比选择方法的讨论》一文中体积法计算混凝土配合比,用加权法计算胶凝材料密度应当使用体积分数。用质量分数和体积分数计算值之差,随粉煤灰掺量的增大而增大,尽管只有10-2百分点之差,而从基本概念上是应当纠正的。饱和面干骨料所含的水,既不对拌合物和易性起作用,在混凝土硬化前也不参与水泥水化,而是属于骨料表观体积的一部分,因此骨料的密度必须使用饱和面干状态的测定值。

To accept professor Ge Yi-xiong＇s comment on that volume percent must be used for calculating the density of cementitious materials by weighted method other than mass percent in calculation of concrete mix proportion by volume method.The different calculated value between volume percent and mass percent would be increased with dosage of fly ash increasing,although that difference would be only 10-2,it must be corrected on the basic concepts.Density of aggregate must be tested in saturation with water and dried surface,because water saturated in aggregate cannot neither touch workability of fresh concrete,nor involve hydration of cement before concrete solidifying.