Concrete surface retarder China

GENERAL

Concrete surface retarder is a brushing paste-like surface retarder. It is an environmentally friendly water-based product formulated with a variety of cement retarding active components. It is directly painted on the formwork and greatly delays the setting of the surface of the concrete. When the internal concrete reaches sufficient strength, the surface of the concrete can be easily washed off with water due to the delay of setting, thereby exposing the internal aggregates.

Application

1. The concrete surface of connecting surface of prefabricated components in the field of prefabricated construction where the aggregates are required to be exposed;

2. The connecting surface of precast concrete panels such as bridges, etc.;

3. Exposed aggregate pervious pavement.

FEATURE

1. Water-based products, safe and environmentally friendly, and easy to operate.

2. It is suitable for different site conditions and template surfaces, including steel template, bamboo plywood and wooden template.

3. The use of iron cones or chisels and other mechanical methods to roughen the surface of the concrete is eliminated, thereby greatly reducing the labor intensity of labor and saving construction costs.

4. The max thickness/etching depth of the retarded concrete (can be adjusted as required) can reach more than 10mm.

5. The product does not reduce the strength of the concrete body and the binding force to the steel bar.

6. No corrosion to steel formwork and steel bars.

7. It can also achieve a good surface retardation effect on steam-cured concrete.

PERFORMANCE

Items		Technical indicators
Appearance		Homogeneous milky white paste
Ph value		6-8
Working hours (H)		≥10
Etching depth		1-10mm
Final strength of concrete		Not affected
Storage stability		No layering and agglomeration during the storage period
Retardation time (H)	Room temperature	Not less than 72H
	60℃	Not less than 14H

Packaging and storage

This product is packed in plastic barrels, 10kg per barrel; this product should be stored between -5 and 30°C and protected from light. The shelf life is 12 months.

Construction process

◆ On the concrete template that needs to be roughened, use a brush to paint a layer of surface retarder.

◆ Pour the concrete and vibrate to compact it. At this time, the surface retarder will immerse into the concrete on the contact surface.

◆ Carry out demolding after the concrete strength reaches the required strength. Demolding shall not be taken longer than 7 days.

◆ Use a high-pressure water gun to wash the uncondensed concrete surface to expose the aggregate and reach the designed etching depth.

◆ The dosage at room temperature is generally 0.2~0.5kg/m2, and the specific dosage should be determined through tests based on factors such as concrete strength grade, curing temperature, etching depth, time for demolding, and construction temperature.

Precautions:

1. The surface of the template must be cleaned before application. There should be no oil stains on the surface of the template, as well as mold release agent. If there is oil stains, the oil stains need to be thoroughly cleaned up, and the oil stains can be cleaned with plain cement slurry for several times to thoroughly remove the oil stains.

2. The depth of the exposed aggregate (etching depth) is affected by the dosage amount of the concrete surface retarder (the thickness of the application), the length of the concrete curing time, the curing temperature, the strength of the concrete, the type and amount of cement, the amount of concrete admixture, and various other factors. The specific data needs to be determined through tests to achieve the best effective.

3. Under the same conditions, the thicker the surface retarder is applied, the deeper the etching reaches and the more aggregates are exposed.

4. After demolding, it should be cleaning with a high-pressure water gun as soon as possible, and the retarder should be all removed to ensure that there is no surface retarder residue on the prefabricated parts.

5. It is recommended that the pressure of the high-pressure water gun is 6~8Mpa, the water gun should be flushed directly against the surface of the component, and the distance between the water gun and the surface of the component that needs to be flushed is not more than 50 cm.

6. Try to avoid washing the components after a few days after the mold is removed, otherwise the washing efficiency will be reduced and the etching depth will be affected.