BestRetard GS320H

• Architectural concrete with rough, uneven surfaces or exposed natural aggregate, etc.

• Concrete at joints or construction joints requiring high roughness to enhance the bond with subsequent material layers.

• Concrete surfaces consisting of multiple concrete layers cast successively on top of one another, or other bonding materials for subsequent steps, etc.

• Concrete with a roughened surface to provide slip resistance, etc.

• Pre-formulated mixture, easy to use, with stable quality.

• High retarding effect and low dosage, resulting in very high economic efficiency.

• Contains no chloride ions and therefore does not cause corrosion of steel formwork upon direct contact with the product.

• Does not reduce the final concrete strength if the product is spilled or mixed into the concrete.

• Does not reduce the final bond strength between concrete and reinforcing steel if the product adheres to the reinforcement before concrete placement.

• Allows the concrete to harden normally once the effective retarding period has elapsed.

• Does not damage the surface bond strength of the aggregate or binder, unlike mechanical roughening methods.

• Easy to clean, non-toxic, and environmentally friendly.

• Does not change the natural color of the concrete surface after the set-retarding period has elapsed and when applied correctly.

• Suitable for all types of Portland cement concrete, including white cement and sulphate-resistant cement.

• Suitable for the hot and humid climate conditions of Vietnam.

APPLICATION PROCEDURE

Application

Using a conventional sprayer or a compressed-air spray gun, apply BestRetard GS320H evenly over the entire concrete surface to be roughened, immediately after the bleeding process of the concrete has just finished and the concrete surface has just become free of standing water.

Immediately after the lower part of the concrete, which has not been penetrated by BestRetard GS320H, completes its setting process—usually about 6–10 hours after the concrete is mixed—however, the upper part of the surface, having absorbed the set-retarding and hardening inhibitor BestRetard GS320H, remains soft and not yet set or hardened, so a brush or a water jet can be used to wash away the unset mortar layer, exposing the rough surface created by the exposed aggregate.

While the concrete surface treated with BestRetard GS320H is in use, it should be protected from direct exposure to sun, rain, wind, and dust.

After washing clean and exposing the aggregate, the concrete is cured according to the normal concrete curing procedure.

Note

• Do not dilute or mix any other product or chemical with BestRetard GS320H when in use.

• Do not allow the product to spill or come into contact with other fresh concrete areas unless required.

• Since the retarding performance and retarding duration of the product depend on many factors during use, such as: the concrete mix design, cement content, water/cement ratio, type of cement used, and ambient temperature during application, trial tests must be carried out for each specific application condition to achieve the desired results regarding the depth of aggregate exposure and the surface washing time.