Can you hit the concrete floor at MINUS 2 degrees?

Best answer: Yes. Once to twice below zero has no effect on cement. In order to prevent early freezing damage, it is usually required that the concrete temperature at the beginning of curing should not be lower than 5 degrees Celsius. Because the heat storage method relies on the hydration heat of cement and the heat of concrete mixture itself, and reaches the predetermined temperature under the condition of heat preservation, the curing temperature should be raised to above 10 degrees Celsius. Therefore, in the process of mixing, transporting, placing and tamping concrete, measures must be taken to prevent the heat from spreading too fast.

Yes. Once to twice below zero has no effect on cement. In order to prevent early freezing damage, it is usually required that the concrete temperature at the beginning of curing should not be lower than 5 degrees Celsius. Because the heat storage method relies on the hydration heat of cement and the heat of concrete mixture itself, and reaches the predetermined temperature under the condition of heat preservation, the curing temperature should be raised to above 10 degrees Celsius. Therefore, in the process of mixing, transporting, placing and tamping concrete, measures must be taken to prevent the heat from spreading too fast. When preparing concrete at negative temperature, water and sand can be properly heated, but the temperature of the mixture of water and sand should not exceed 40℃, otherwise false setting will easily occur when cement is put into use. In addition to heat curing, concrete can also be mixed with early strength agent and antifreeze in winter to lower its freezing point and harden concrete at negative temperature. When chlorine salt is mixed in concrete, its mixing amount should be strictly controlled. Chlorine salt can corrode steel bars and increase the conductivity of concrete, so it can only be used for unreinforced concrete. For prestressed concrete structures, or buildings that are often wet or close to high-voltage power supply, chlorine salt should not be mixed. When preparing concrete in winter, air-entraining agent (see concrete admixture) can be added. Its purpose is to use concrete to contain a large number of evenly distributed micropores, so as to slow down the damage of freezing pressure of free water to the capillary structure in concrete, thus improving its frost resistance. However, the increase of air content will affect the compactness and strength of concrete, which should be controlled.

Leave a Reply 0

Your email address will not be published. Required fields are marked *