混凝土搅拌二次投料法是改革混凝土制作的一项新工艺,目前正在全国普遍推广使用.一般分为二种方法:即先拌水、水泥,后投砂、石的“先拌水泥浆法”和先拌水泥及饱和水的砂,再投入剩余的水和石子的“水泥裹砂法”.通过改变投料程序,在搅拌过程中,使水泥颗粒充分分散并包裹在砂子表面,避免产生小水泥团,充分发挥了水泥的作用,明显地改善混凝土的均匀性,提高保水性、提高混凝土强度,节约水泥并缩短蒸养时间,不需要增添设备,操作又很方便,经济效果显著,易于为广大混凝土专业人员接受,是一项切实可行,值得推广使用的新技术. Concrete mixing re-feeding method is to reform the production of concrete is a new technology, is currently being widely used throughout the country .Generally divided into two kinds of methods: the first water, cement, sand, stone after the “first mixed water slurry method” And first mixed with cement and saturated water sand, and then put the remaining water and gravel “cement wrapped sand method.” By changing the feeding process, in the mixing process, the cement particles fully dispersed and wrapped in the sand surface, to avoid the production of small cement Mission, give full play to the role of cement, significantly improve the uniformity of the concrete, improve water retention, improve concrete strength, save cement and shorten the steam curing time, do not need to add equipment, operation is very convenient, economic effect is obvious, easy for the majority Concrete professionals to accept, is a practical, worth promoting the use of new technologies.