Concrete Powder Retarder

Concrete Powder Retarder

LP63

Powder Additive for Delaying Concrete Setting Time

Suitable for Large-Scale Concrete Pouring

Concrete Powder Retarder Description

Concrete powder retarder is an effective crystalline product that, when added to concrete, slows down the hydration rate and delays the setting time. This powder retarder, or slow-setting agent, prevents the premature setting of concrete or mortar by creating a controlled delay in the setting time. This makes the concrete placement easier and contributes to a smooth surface finish.

In general, this product is an additive capable of slowing the setting of cement mixtures, or in other words, delaying the setting of mixtures such as mortar or concrete. It is also recognized as a set-retarding additive.

Mechanism of Action of Concrete Powder Retarder

Concrete powder retarder works by reducing the rate of cement hydration or, in other words, the reaction between cement and water. This directly affects the hydration process and reduces water penetration into cement particles.

It should be noted that the use of a powder retarder is one of the factors that influence the setting time of concrete. Other elements, such as the type of cement, the water-to-cement ratio, and environmental temperature, also have a significant effect on setting time.

The type of cement used directly impacts the effectiveness of this additive. Cements with low C3A content and low alkalinity have a higher retardation value compared to cements with higher C3A and higher alkalinity. Therefore, cements with low C3A content absorb less additive, and a higher amount of slow-setting agent is required to achieve the desired retardation effect and control the C3S hydration process.

Properties and Effects of Concrete Powder Retarder

• Delays the setting time of concrete
• Reduces cold joints caused by delays in concrete pouring
• Improves long-term concrete strength
• Enhances surface finishing of concrete
• Facilitates concrete placement in windy areas
• Increases workability and ease of concrete placement
• Allows for longer transportation distances between batching and pouring sites
• Prevents surface cracking due to shrinkage
• Suitable for hot weather concrete pouring

Applications of Concrete Powder Retarder

• Large and semi-large scale concrete pours
• Ideal for pumpable concrete applications
• Long-distance transportation of concrete
• Manufacturing high-strength and impermeable concrete
• Suitable for architectural concrete applications
• Ideal for roller-compacted concrete
• Suitable for large-scale projects such as dams, bridges, and heavy foundations

Physical and Chemical Specifications of Concrete Powder Retarder

Property	Value
State	Liquid
Color	Brown
Specific Gravity	0.98 g/cm³
Chloride Ion	None
Standard	ASTM C494 – ISIRI 2930 – EN 934-2

Concrete Powder Retarder Consumption Rate

The consumption rate of concrete powder retarder depends on the ambient temperature and the required delay time for setting. The recommended amount is between 0.2% and 0.6% of the cement weight.

Note that the exact dosage of the retarder should be determined through precise laboratory tests, considering various factors such as the type of cement, water-to-cement ratio, ambient temperature, and the required retardation time.

How to Use Concrete Powder Retarder

1. Dilute the required amount of powder retarder, considering the concrete mix ratio, with twice the volume of mixing water. Gradually add the diluted additive to the mixing concrete.
2. The product can be added to the prepared concrete mix, followed by thorough mixing before pouring.

Note: It is recommended to mix for at least 1 minute per cubic meter of concrete.

1. The powder retarder can be added to the dry ingredients before water is added to the mix.

Safety of Concrete Powder Retarder

• The retarder is not considered toxic, flammable, or environmentally hazardous.
• Do not ingest the retarder or allow it to come into contact with eyes.
• If the retarder contacts the skin or eyes, rinse immediately with plenty of clean water.
• If ingested, seek medical attention immediately.

Storage of Concrete Powder Retarder

• Shelf Life: 1 year in its original packaging.
• Storage Conditions: Store in a dry place away from freezing temperatures, heat, and prolonged direct sunlight.
• Ideal Storage Temperature: 10+ to 30+ degrees Celsius.

Concrete Powder Retarder Packaging

• Packaging: 20 kg bags