Concrete powder retarder
Description
Description: Concrete powder retarder
Powder concrete retardant is an efficient crystalline product that, after being added to the concrete, reduces the speed of concrete hydration, causes delays in the time of concrete settling.
Features:
- Expansion of surface polishability of concrete
- Increasing the time of concrete performance or workability
- Prevent surface cracks caused by retraction
Applications:
- Suitable for bulk and semi-bulky concretes
- Ability to build strong and impervious concretes
- Construction and transportation of concrete over long distances
Technical specification table:
| Appearance | Powder |
| Color | White |
| Specific gravity | 1 gr/cm3 |
| Standard | ASTM C494
ISIRI 2930 EN 934 – 2 |
| PH | 8 |
| Chlorine ion | Doesn’t have |
Package:
20kg bag
Product Description – Powdered Concrete Retarder
Powdered concrete retarder is an efficient product in crystalline form that, when added to concrete, slows down the rate of concrete hydration, thereby delaying the setting time of concrete. Powdered concrete retarder or powdered concrete retarder, when added to mortar, prevents premature hardening of concrete or mortar by creating a controlled delay in setting time, and while facilitating the concreting process, it also provides a smooth and polished surface. Also, using retarders is very suitable for implementing projects with high concrete volume, such as dams, bridges, large-volume foundations, etc.
Powdered concrete retarder is an efficient crystalline product that, when added to concrete, slows down the rate of hydration of the concrete. This results in a delay in the setting time of the concrete and provides greater flexibility during construction. Powdered retarders are commonly used to adjust the setting time of concrete and improve its workability. These types of additives slow down the setting of cement paste and concrete mix and delay the setting time. If you are working with concrete, using a retarder can be useful for managing the setting process of the concrete.
Delayed setting packaging of powdered concrete
20 kg bag
Consumption rate of powdered concrete retarder
Depending on the air temperature and the length of time required to delay the setting time of the concrete, the amount of powdered concrete retarder used is 0.2 to 0.6 percent of the weight of the cement used.
Also note that the exact amount of concrete retarder to be used must be determined by conducting detailed workshop tests and taking into account various factors such as the type of cement used, the water-to-cement ratio, the ambient temperature, the required retarding ratio, etc.
Delayed maintenance of powdered concrete
Duration: One year in original packaging.
Conditions: Away from cold and frost, heat and direct and prolonged sunlight.
Best storage temperature: +10 to +30 degrees
Method of using powdered concrete retarder
- The amount of powdered concrete retarding admixture calculated according to the grade of concrete should be diluted with 2 times the volume of concrete mixing water. Then, the diluted admixture should be gradually added to the concrete being mixed.
- Powdered concrete retarder product can be added to dry ingredients before adding water to the mix.
- This chemical concrete additive can be added to the ready-mixed concrete and, after complete mixing, concreting can be carried out.
Note: It is recommended to mix for at least 1 minute per cubic meter of concrete.
Properties and retarding effects of powdered concrete
- Developing the polishability of concrete surfaces
- Delaying the setting time of concrete
- Increasing the long-term stability of concrete
- Reducing cold joints caused by concreting intervals
- Possibility of constructing and implementing concreting in tropical regions
- Possibility of constructing and implementing concrete in windy areas
- Preventing surface cracks caused by shrinkage
- Increasing the working time or workability of concrete
- Possibility of concreting with a long batching distance to the point where the concrete is discharged from the injection pipe
Applications of powdered concrete retarders
- Suitable for the manufacture and application of architectural concrete
- Bulk and semi-bulk concreting
- Suitable for implementing projects with high concrete volume, such as dams, bridges, large-volume foundations, etc.
- Suitable for the production and application of roller concrete
- Making and transporting concrete over long distances
- Suitable for pumping concrete.
- Making durable and impermeable concrete
Table of physical and chemical properties of powdered concrete retarder
| Title | Feature |
| Mode | Liquid |
| Color | Brown |
| Specific gravity | 0.98g/cm3 |
| Chlorine ion | No |
| Standard | ASTM C494 – ISIRI 2930 – EN 934 – 2 |
Mechanism of the retarding effect of powdered concrete
Powdered concrete retarders reduce the rate of cement dehydration, or in other words, the reaction between cement and water, and have a direct effect on the hydration process, while also reducing the rate of water penetration into cement particles.
It should be noted that the use of powdered concrete retarding admixture is one of the factors that delay the setting of concrete, and other elements such as the type of cement, water-to-cement ratio, and ambient temperature have a significant impact on setting time.
The type of cement used has a direct relationship to the retarding rate of the powder concrete retarding admixture. Cements with low C3A and low alkalinity will have a higher retarding rate than cements with high C3A and higher alkalinity, and this is because cements with low C3A will absorb less admixture. Therefore, more retarding cement will be left to act, react, and delay the C3S hydration process.
Safety of powdered concrete retarders
- The powdered concrete retarding admixture is not a toxic, flammable, or environmentally hazardous substance.
- It should not be swallowed or come into contact with the eyes under any circumstances. If swallowed, seek medical attention immediately.
- In case of contact with skin or eyes, wash with plenty of fresh water.
- Wear appropriate gloves, mask, and goggles when working.
Standard powder concrete retarder
ISIRI 2930 standard – EN 934 – 2 – ASTM C494
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