Because after concrete pouring for a certain period of time, it is necessary to spray water for maintenance. After the plastic film is pasted, the water inside the concrete can't evaporate, but remains inside the concrete, which provides water for the maintenance behind the concrete. This can reduce the number of manual watering maintenance, the use of artificial, but also timely maintenance of concrete.
Extended data:
Concrete curing is to artificially create certain humidity and temperature conditions, so that the newly poured concrete can be normal or accelerate its hardening and strength growth. The gradual hardening and strength increase of concrete is the result of cement hydration, which requires certain temperature and humidity conditions.
If this situation does not exist in the surrounding environment, it is necessary to maintain the concrete manually. Concrete curing methods are:
1, natural curing: divided into sprinkler curing and plastic film spraying curing.
1. 1. The former covers the concrete with a straw curtain and often sprinkles water to keep it moist. The curing time depends on the type of cement, such as ordinary portland cement concrete not less than 7 days and nights.
1.2, which is suitable for high-rise structures and large-area concrete structures that are not easy to be cured by water spraying. The perchloroethylene resin plastic solution is sprayed on the concrete surface with a spray gun. After the solution volatilizes, a thin film is formed on the surface of the concrete, which isolates the concrete from the air, prevents the water in the concrete from evaporating and ensures the normal hydration of the cement. After maintenance, the film can age and fall off by itself.
2. Steam curing: put the concrete members into a curing room filled with saturated steam or a mixture of steam and air to accelerate the hardening of concrete in a high temperature and high humidity environment. The curing effect is related to the steam curing system, including:
Standing time before steam curing, heating and cooling speed, curing temperature, constant temperature curing time, relative humidity, etc. Steam curing room has pit type, vertical kiln type and tunnel kiln type.
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