我国现行规范规定,试验室选定的混凝土计算配合比,试配时,必须通过试拌,验证拌合物的和易性、粘聚性、保水性及表观密度、强度、调整用水量或砂率,使之符合原定要求,最后根据工地的砂、石含水情况,把经试拌与调整后的配合比,换算成施工配合比。砂中所含水份直接导致砂子体积的增加和拌合物干密度 China’s current norms, the laboratory selected concrete calculated mix, the trial, the trial must be mixed to verify the workability of the mixture, cohesion, water retention and apparent density, strength, adjust the water or Sand rate, so that it meets the original requirements, and finally according to the site of sand, stone water conditions, the test mix and adjust the mix, converted into construction mix. The moisture contained in the sand directly leads to an increase in the volume of sand and the dry density of the mixture