How to deal with concrete after molding? What are the reasons for concrete mold expansion? And how t

Concrete post-mold treatment method:

1. First of all, the concrete of the expansion part to be repaired is chiseled, so that the small hammer is fine chisel to avoid damaging the structural reinforcement. It is required that the surface of the concrete after chiseling can achieve the effect of cutting fake stones, and there are no loose stones and concrete particles.

2. Brush the chisel parts with a brush and rinse them with water to make them free of loose stones and dust.

3. Paint a layer of cement slurry with the same cement for interface treatment on the repair site, so that the old and new concrete can be well combined.

4. After the final setting of concrete, strengthen sprinkling and curing to avoid cracking at the junction of new and old concrete.

Expansion mold part treatment plan: after the template is dismantled, it is found that the concrete has the expansion of the mold, the technical quality personnel should promptly notify the supervision engineer to the site to check, the supervision engineer to check the completion of the operation personnel to the expansion of the mold part of the concrete chisel, the chisel shall not damage the structural reinforcement, after the completion of the chisel, the project department technical personnel inspection qualified, notify the supervision engineer acceptance, after the acceptance of the acceptance of the clear water will be watered and moistened with the chisel part, with the same cement configuration 1:2 1:

The cement mortar is debugged and compared before repairing, and the cement mortar is put into the barrel and stirred evenly after debugging, and the chisel surface is scraped and calendered with a scraper according to the method of scraping putty by the painter, and then cured in accordance with the concrete curing method.

If there is a large area of the expansion mold, affecting the size of the structure, then only smashed and re-poured, if it is only a small part, then it can be appropriately removed and repaired with points.

The fundamental reason for the concrete expansion and collision of the free code mold is that the formwork reinforcement and fastening measures are not effective, the stiffness of the mold board itself is insufficient or the formwork is damaged;

Of course, there are many other inducements, such as the impact force caused by the pouring height and angle when pouring concrete.

Too large, too concentrated, formwork support.

The surface is unstable and depressed, and the formwork is impacted during the pouring process, etc.;

Basically, the concrete expansion mold does not have much impact on the integrity and stability of the structure itself, mainly the impact on the appearance, of course, for the engineering parts with strict size requirements, the size deviation due to the expansion mold will also affect the use function.

There are not many specific treatment methods, nothing more than grinding or chiseling and then repairing, generally few because of the expansion mold and the concrete structure is completely chiseled and redone

Expansion mold treatment measures and methods; The deviation is chiseled clean, rinsed with water, and fully moistened, and repaired with cement mortar of the same ratio as the original mixture. When chiseling, it is not allowed to cut off the steel bar at will, such as when the steel bar must be cut, it must be reported to the engineering department, the technical department, the quality assurance department, and other relevant departments to study the treatment plan, and then cut off the treatment, and carefully maintain.

If the concrete pouring process encounters the phenomenon of expansion mold and burst mold, the pouring of the part must be stopped immediately, and under the condition of ensuring safety, immediately repair and reinforce or re-support the formwork according to the design requirements of the scheme. And after the re-acceptance can continue to pour.

The main causes of mold expansion; The spacing of the wall formwork to the tension bolts is too large, and the bolt specifications are too small, resulting in an expansion mold. The number of formwork tie rods is insufficient, and the concrete vibrating tie rod screws collapse, resulting in the formwork bursting. The spacing between the beam and column formwork fixtures is too large, and the number of unclamped formwork or tie rod bolts is insufficient, resulting in local molds.

In order to improve the crack resistance of cement concrete, compensate for shrinkage, and even produce chemical prestress inside the concrete, expansion concrete can be prepared by using expansion cement or mixing expansion agent in concrete.

If it is a foundation cushion cap, it does not need to be processed.

If you want to deal with it, you can stop pouring concrete immediately, clean the concrete, and re-support the formwork; You can also wait for the concrete to harden and remove the mold, and then use the air cannon to knock off the excess part.

When the concrete may be in contact with the flowing water after the demoulding is removed, the concrete should be cured with effective thermal insulation and moisturizing measures before the contact with the flowing surface water or groundwater, and the curing time should be extended (at least 14d) than the time specified in the above table, and the strength of the concrete should reach more than 75% of the design strength. After the end of curing, it should be backfilled in time.