Concrete mixer feeding sequence 1: in the production of concrete below C30, it is usually used to cast stones first, then cement, sand, water, feed in turn, one-time mixing molding, so it is also called "one-time feeding method". Changing the feeding method can effectively reduce the phenomenon of cement sticking to the wall. This kind of concrete is usually used in the construction of site hardening, rural roads and houses below three floors.

混凝土搅拌机投料顺序2：先投料沙子，水泥，水一次性投料，搅拌1-1.5分后，在将石子料投入搅拌机搅拌1-1.5分，这种投料方法具有可以使水泥沙子重复的搅拌的优点，这种投料方法叫做预拌水泥砂浆法。

Concrete mixer feeding sequence 2: first feeding sand, cement, water, one-time feeding, mixing 1-1.5 points, after the stone material into the mixer mixing 1-1.5 points, this feeding method can make the cement sand repeated mixing advantages, this feeding method is called premixed water mud mortar method.

混凝土搅拌机投料顺序3：先将水泥和水充分搅拌成均匀的水泥净浆后，再加入砂和石子搅拌成混凝土。国内外的试验表明，二次投料法搅拌的混凝土与一次投料法相比较，混凝土的强度可提高15% ，在强度相同的情况下，可节约水泥15%-20%。

Concrete mixer feeding sequence 3: first mix the cement and water into a uniform cement paste, and then add sand and stones to mix into concrete. The tests at home and abroad show that the strength of concrete mixed by twice feeding method can be increased by 15% compared with that by once feeding method, and the cement can be saved by 15% - 20% under the same strength.

混凝土搅拌机投料顺序4：该法的搅拌程序是先加一定量的水使砂表面的含水量调到某一规定的数值后(一般为15%-25%)，再加入石子并与湿砂拌匀，然后将全部水泥投入与砂石共同拌合使水泥在砂石表面形成一层低水灰比的水泥浆壳，将剩余的水和外加剂加入搅拌成混凝土。采用SEC 法制备的混凝土与一次投料法相比较，强度可提高20%-30%，混凝土不易产生离析和泌水现象，工作性好。

Concrete mixer feeding sequence 4: the mixing procedure of this method is to first add a certain amount of water to adjust the water content on the sand surface to a specified value (generally 15% - 25%), then add stones and mix well with wet sand, and then put all the cement into mixing with sand, so that the cement forms a layer of cement slurry shell with low water cement ratio on the sand surface, and add the remaining water and additives to mix Concrete. Compared with the one-time feeding method, the strength of concrete prepared by SEC method can be increased by 20% - 30%. The concrete is not easy to produce segregation and bleeding, and has good workability.