What about hydration reaction of cement blanket

Cement blanket is a kind of soft cloth impregnated with cement, which will react with water and harden into a very thin waterproof and fireproof durable concrete layer. The cement blanket is made of 3D fiber matrix woven with polyethylene and polypropylene filament, and contains dry concrete mixture with special formula. The main chemical components of calcium aluminate cement are Al2O3, Cao, SiO2 and Fe2O3. The bottom of the canvas is covered with polyvinyl chloride (PVC) backing to ensure that the cement blanket is completely waterproof. During site construction, there is no need for any concrete mixing equipment on site, as long as the cement blanket is simply watered or soaked in water to make it hydrated. After solidification, the fiber can strengthen the concrete and prevent cracking. At present, the cement blanket is 10 mm thick.

1. This material is used in Central China, and its design life is more than 50 years. In order to prolong the service life, it is suggested that the material should be maintained every 5-10 years, and a layer of cement slurry should be brushed on the surface of the material blanket, which can effectively extend the service life of the material.

2. After the strength of the material reaches 10.0MPa, it can bear the load of personnel and light construction machinery.

3. It is not allowed to knock or pull the material after pouring water until the final strength is formed; it is not allowed to knock the material with sharp objects.

The new cement blanket can be hydrated with salt water or non salt water. The minimum weight ratio of water to cement blanket is 1 ∶ 2. Excessive hydration of cement blanket will not occur, so it is always recommended to use excessive water. Water can be sprayed several times on the fiber surface until the cement blanket is saturated. Because the cement blanket absorbs moisture, it darkens first and then becomes lighter. When water accumulates or flows down the surface, the cement blanket is saturated with water. After the initial hydration reaction, the cement blanket shall be re wetted at least once between one and two hours. This is especially necessary in high temperature and dry weather, as evaporation of water can cause excessive drying of concrete.

Hj008 Hanji cement blanket is the most prone to excessive drying. No matter what the weather is, one to two hours after hydration reaction, it should be rewatered once or more. Do not use high-pressure water spray gun to spray water directly on the cement blanket, otherwise the surface of cement blanket will be washed into groove shape. If the cement blanket is not fully protected by water, the setting will be delayed and the material strength will be improved

It will go down. If the setting time is delayed, it should be rewatered with a large amount of water. Cement blanket can be used under water. At this time, because it is immersed in water, hydration reaction can take place fully.