Concrete Quality Control Measures in Winter

During the winter construction period, the quality of the project is not only a matter of the mixing station, but more importantly, the construction unit should take necessary measures. Without the cooperation of the construction unit, it is difficult to guarantee the quality of the project no matter how good the concrete is. Before entering the winter construction period, the construction unit should make full preparations and pay attention to the following measures for winter concrete construction insulation:

1.Strict construction organization and strengthen liaison, and the construction party shall provide detailed and accurate concrete pouring location, strength grade, concrete dosage, construction method, and whether there are special requirements before production. Lignosulfonate concrete admixture is widely used in construction.

1. Do a good job of heat preservation and moisturizing, and strengthen temperature monitoring. In winter, due to the large temperature difference between day and night, the night temperature is often lower than 0?, so cold and frost-proof materials should be prepared in advance. Such as commonly used plastic film, color striped cloth, cotton felt, straw bag, and so on. After the temperature is lower than 0?, temperature monitoring should be strengthened, and the temperature should not be measured less than once every 2 hours so that timely measures can be taken.
2. Before pouring the concrete, the ice, snow, and dirt on the formwork, steel bars, and iron parts must be removed, but they should not be washed with water to avoid freezing again.
3. During winter construction, no concrete pouring is allowed on the frozen soil layer, and the temperature must be raised to melt the frozen soil before pouring. For large-volume concrete that needs to be poured in layers, the temperature of the poured layer of concrete before it is covered by the upper layer of concrete should not be lower than 2°C.
4. When the concrete is rubbed, it should be preheated and rubbed, and heat preservation shall be strengthened after pouring to prevent the rubbed concrete from freezing and reduce the bonding force and strength of the concrete.
5. It is strictly forbidden to add water to the tank car arbitrarily to prevent the local water-binder ratio from being too large, causing cracks and strength reduction in the structural parts.
6. Ensure the continuity of production, transportation, and concrete pouring, reduce the residence time of concrete in the pumping pipeline, and prevent excessive temperature drop from stagnating and blocking the pipe. Ensure that the temperature of concrete entering the mold is not lower than 5°C.
7. The insulation layer outside the formwork and the concrete surface should not be made of wet materials, nor should the insulation material be directly covered on the wet concrete surface. The surface of the newly poured concrete should be covered with a plastic film and then covered with the insulation material.
8. After pouring, heat preservation must be strengthened for the frost-prone parts of the concrete to prevent the concrete from frost damage.

10.In winter construction, the temperature is low. The initial setting time of concrete is generally 8-10 hours, and the final setting time is 12-14 hours. The timing of plastering should be grasped. Rub flat, once iron trowel compaction) to reduce shrinkage cracks on the concrete surface. Prolong the mold removal time of side molds such as concrete walls and columns to avoid defects such as surface sticking and corner drop.

11.After the concrete is vibrated, compacted, and compacted, it must be covered with plastic film, straw curtains, and other thermal insulation materials in time for thermal insulation and moisturizing maintenance to ensure that the concrete is not damaged by freezing before the initial setting. According to the structure and the temperature, it is generally: a layer of plastic film and a layer of insulation material when the temperature is 0?-5?; a layer of plastic film and three layers of insulation material when the temperature is -10?-0?. The insulation thickness of the opposite edges and corners should be increased to 2-3 times that of the surface.

Kingsun is a professional concrete admixtures manufacturer and supplier.