Foam Concrete Maintenance Precautions

Foam concrete is a new building material that has developed rapidly in recent years. It is quite different from traditional concrete in all aspects, so foam concrete also has its own specific methods for maintenance.

1. Cover watering and maintenance

Covering and watering maintenance is based on the outside temperature. Generally, the concrete should be covered with appropriate materials such as straw curtains, reed mats, sacks, sawdust, wet soil and wet sand within 3-12 hours after the foam concrete is poured, and watered frequently to keep it moist.

① The watering and curing date of foam concrete shall not be less than 7 days and nights for concrete mixed with Portland cement, ordinary cement and slag cement.

② Mixing of retarding admixture or concrete with impermeability requirements shall not be less than 14 days and nights.

③When using bauxite cement, it should not be less than 3 days and nights.

④ The number of daily waterings should be enough to keep the concrete in a sufficiently moist state. When the temperature is above 15°C, in the three days and nights after the concrete is poured, watering should be done at least once every 3 hours during the day and twice at night. In the future maintenance, watering should be done at least 3 times a day (of course, when the temperature is dry, the frequency of watering can be increased appropriately).

⑤ For larger areas (or volumes) of concrete, "water storage curing" should be used. For projects such as storage tanks, watering and curing can be done after the inner mold is removed and the concrete reaches a certain strength; for underground structures or foundations, the surface can be painted with asphalt emulsion or backfilled with soil instead of watering for curing.

2. Plastic film maintenance

Plastic film curing refers to using a plastic film covering to separate the concrete from the air so that the water is no longer evaporated. The cement relies on the moisture in the concrete to complete the hydration and has reached condensation and hardening. This method can directly cover the surface of the concrete with plastic draft, or spray the plastic emulsion on the surface of the concrete component. After the emulsion evaporates, it is combined into a layer of plastic film on the surface of the concrete to isolate the concrete component from the air, so that the water in the concrete will no longer evaporate and complete the hydration. The disadvantage of spraying plastic film curing is that the concrete strength is about 8% lower at 28 days, and because the film is thin, it cannot fully achieve the effect of heat and freezing. Therefore, when using this method in the summer, it is necessary to add sun protection facilities (not less than 24 hours), otherwise it will cause filamentous cracks in the foam concrete.

3. Precautions

① Within 72 hours of pouring the foam concrete, it is strictly prohibited for anyone to step on it;

② During the maintenance period, you are not allowed to wear spiked shoes to walk on it, you are not allowed to stack heavy objects, you are not allowed to pull cars on it, and you are not allowed to drill holes on it to install pipes, brackets, etc.;

③ After the completion and acceptance of the insulation layer, the protective layer should be completed in time to prevent damage to the insulation layer during the pouring of the backfill protective layer. Drilling holes in the completed insulation layer should be avoided. If drilling and holes are really necessary, the damaged insulation layer should be sealed with focus;

④After delivery, the load on the foam concrete cannot exceed its compressive strength (1.2-1.5Mpa).