1. Raw materials: Quality shall meet JC476-1998 standards, cement shall be qualified and unexpired Grade 32.5 (original 425) or above, coarse aggregate particle size shall meet concrete specification requirements, content less than 1%, fine aggregate shall be medium coarse sand with mud content less than 3%, water shall be tap water or clean river water, UEA content shall be 8-10% of cement weight.

2, when the sequential application of mixing conveying materials: AEA gravel - water - power operation ---- sand cement sand dry mixing - above 30S. Retarders can be incorporated into concrete transport and maintain continuity over time exceeding 1.5 hours, rather than a time interval, transmission distances longer or in hot weather to reduce slump; Mixing time after adding water half a minute or longer than ordinary concrete loss.

3. Do not add the product when the material is stirred, because the stone and sand contain a lot of water, the accelerator absorbs water in a short time. In the absence of injection, the decomposition of its rapid condensation will affect the analytical condensation and reduce the structural strength of engineering concrete, which will lead to adverse effects of injection concrete.

4, before use, should be used in the project of cement varieties test, choose the amount, can be used in large quantities,

5, cement can not be used to store expired, do not meet the standard of cement can not be used, custody prevention needs to accelerate the water barrier failure.

6, strengthen the early water maintenance, ensure the strength of the later period, strict requirements to master a good water-cement ratio.