Precautions for cement use are as follows
1, to avoid getting wet and hardening.
Cement hardened by moisture will reduce or even lose its original strength, so the specification stipulates that cement that has been shipped for more than 3 months should be re-tested and used according to the test results. Cement caked or hardened by moisture must be screened before use. The screened aggregates are generally used for masonry mortar or plastering mortar in secondary projects after rubbing or grinding. For cement blocks that can be pulverized by one touch or one pinch, the strength grade can be appropriately reduced.
2, avoid exposure and quick drying
Concrete or plaster will be exposed to the sun after operation, and its strength will be reduced or even completely lost with the rapid evaporation of water. Therefore, before construction, the base must be strictly cleaned and fully wetted; After construction, it should be strictly covered and watered and maintained according to regulations.
3. Avoid freezing at negative temperature.
After mixing concrete or mortar, if it is frozen, its cement can't hydrate, and water freezes and expands, then the concrete or mortar will be destroyed by the gradually deepening powder cake from the outside to the inside, so it should be carried out in strict accordance with the Code for Winter Construction of Building Engineering (JJ104-97).