A. Cement. The label is clear and the quality can be used only after the quality has been signed (quality guarantee certificate should be issued in batches). Common cement labels are 325 #, 425 # or 525 # ordinary Portland cement or slag cement. Cement is not allowed to be stacked in the open air. If the storage time of cement exceeds three months, the use of the label should be reduced according to the actual situation (the strength of cement should be reduced by 20% after three months of storage).

B. Huangsha. In accordance with the principle of local sampling, it is required that the material be hard, clean, well graded and contains no more than 3% sediment. Otherwise, it should be washed clean and easy to use. Medium and coarse sand is suitable for concrete mixing, and fine sand can be used for mortar.

C. Stones. Choose hard, angular, rough surface of massive gravel, stone particle size should meet gradation standards, clean and clean, the maximum particle size of stones should not exceed one quarter of the minimum cross-section thickness.

D. Water. All tap water and natural water suitable for drinking can be used. Untreated industrial wastes, marsh water and water with high salt content shall not be used for mixing and curing concrete.