The use of concrete mixers 

First add part of the water and sand, and then the stones, cement and the remaining water (1) the first to add sand and cement, and then add water; (3) the use of feeding hopper feeding, should also be in the above order, in 15 seconds to feed all the material into the mixing cylinder. The above method can avoid the cement cement bucket wall, reduce wear and improve productivity, but the concrete strength is reduced, the cement consumption is larger; it is best to use the first mixing slurry slurry method. It must also be noted that the capacity of the concrete mixer should meet the mechanical capacity of the quota, too small will reduce the productivity; too large not only increase the load of power, but also easy to make concrete slurry spill, stirring efficiency will be reduced. In addition, when the previous concrete has not been completely discharged, no new mixing material should be loaded.