How should GRC components be cured?

2022-05-17

second

GRC can be shaped into any shape and appearance effect, which can meet the designers and owners' unlimited imagination of the building appearance, thus making it appear that the building has a richer decorative effect. In order to obtain high strength, GRC components must be cured. How should we do this? This is also what many construction workers are puzzled about. Then Shenzhen Ouya Building will share with you how to maintain GRC components.

The main way to maintain GRC components is to ensure that the water contained in the GRC components at the early stage will not evaporate. The water contained in the GRC components is necessary in the cement hydration reaction. Only enough water can ensure that the cement can have good strength and reduce its penetration and shrinkage. As hydration will be affected by temperature, the ambient air shall be kept at a proper temperature during the curing of GRC members.

During the maintenance of GRC components, the following points should be achieved:
① Have appropriate early strength to facilitate demoulding and handling;
② Ensure a certain design strength;
③ Shrinkage is limited to prevent cracking.

The actual curing process of GRC components needs to be divided into the following stages:
① After finishing, it is usually necessary to use clean and high-quality polyethylene film to wrap the mold to place the moisture in the GRC component affected by evaporation and wind, while also helping to maintain the heat of hydration. At the initial stage of curing, it should ensure that the GRC component can have sufficient strength, so that it will not be damaged during demoulding and handling.
② In order to continue to protect the GRC components after demoulding from the impact of light, low humidity of wind, rain and air, generally, the GRC structures are still wrapped with plastic film to avoid direct sunlight, and local humidity can also be maintained by spraying wet fog.
③ During the storage and use of GRC components, due to the obvious difference between the surrounding environment and the maintenance stage, certain maintenance operations are also required. At this time, some simple methods can be used to ensure that GRC components will not be directly exposed to the sun during storage.

Accelerated curing mainly includes low-pressure steam curing and the use of chemical early strength agent, which are both effective. Low pressure steam curing has great economic benefits in cold weather. The temperature should not exceed 50 ℃, otherwise it will have adverse effects on long-term strength; The use of chemical early strength agent is mainly used to improve the early strength, which will play a certain role in cold conditions, and can enable GRC components to complete demoulding earlier.