Concrete Powder Shotcrete
FSP62
Powder Additive for Accelerating Hydration Rate
Suitable for Concrete Spraying Operations
Concrete Powder Shotcrete Description
Concrete powder shotcrete is an additive that accelerates the initial setting of concrete and achieves optimal stability in the shortest time possible. The presence of calcium, magnesium, and materials that regulate the pH in this product facilitates rapid cement setting. This additive is used for quick-setting shotcrete and the application of strong, durable concrete layers via the shotcrete method. When applied as dry shotcrete, the powder is sprayed onto the concrete surface using compressed air, accelerating the hydration process. As a result, the initial and final setting times of the concrete are significantly reduced, allowing the concrete to reach its desired hardness more quickly. Additionally, the use of this product helps prevent concrete freezing.
In general, this additive is applied using compressed air to rapidly dry the concrete. It offers excellent resistance to corrosion and increases load-bearing capacity due to stress redistribution.
Mechanism of Action of Concrete Powder Shotcrete
The effectiveness of the concrete powder shotcrete additive depends on various factors, such as the amount used, the type of material mixture, ambient temperature, concrete temperature, cement type, water-to-cement ratio, and curing conditions.
As is evident, when cement interacts with water, hydration begins, and the cement hardens to achieve resistance. This process starts when the cement dissolves in water and, after a dormant period, forms C-S-H gel, eventually completing the setting process. The concrete powder shotcrete additive accelerates this process, speeding up the setting time.
It is important to note that the most effective result is obtained when the ratio of C3A to SO3 is greater than 4.
Properties and Effects of Concrete Powder Shotcrete
- Accelerates initial and final setting time of concrete
- Reduces rebound during shotcrete application
- Increases hydration rate and heat of hydration
- No corrosion of metals due to the absence of chloride
- Decreases the time required for curing and protection
- Prevents concrete from freezing
- Achieves higher stability in a shorter time
- Reduces noticeable aggregate segregation after spraying
- Improves bonding and reduces material fallout due to rapid setting
Applications of Concrete Powder Shotcrete
- Adjusting cement setting time
- Suitable for shotcreting concrete up to 35 cm thickness in a single layer
- Ideal for lining tunnels, channels, and underground structures
- Applicable for shotcrete on curved or irregular sections
- Allows for shotcrete in varying thicknesses
- Suitable for shotcreting to stabilize soil beds
- Can be used in cold weather conditions for concrete pouring
- Useful in areas where formwork is not feasible
- Concrete spraying on sloped or overhead surfaces
- Repairing concrete structures
- Used in tunnel construction as a stabilizing agent
- Facilitates soil stabilization and improvement via chemical injection
- Shotcrete or sprayed concrete applications
- Stabilizing and reinforcing sandy soils
- Enables shotcreting in all directions
Physical and Chemical Specifications of Concrete Powder Shotcrete
| Property | Value |
| State | Powder |
| Color | White |
| Specific Gravity | 1 g/cm³ |
| Chloride Ion | None |
| Standards | ASTM C1141 – ASTM C1398 |
Concrete Powder Shotcrete Consumption Rate
The exact consumption rate of concrete powder shotcrete depends on factors such as the required setting speed, the time available for concrete spraying, the surface moisture level, ambient temperature, cement type, and water-to-cement ratio. To determine the precise amount, laboratory tests should be conducted at the project site, considering the mentioned conditions. Typically, the consumption rate is between 2% and 7% of the cement weight.
How to Use Concrete Powder Shotcrete
- The concrete powder shotcrete should be added to the dry materials and combined with water as it exits the spraying device, initiating the reaction.
- If wet sand is used in the mix, the powder should not be added to the dry materials. In this case, the shotcrete powder must be added to the mixture just before it combines with the water.
Safety of Concrete Powder Shotcrete
- If the powder comes into contact with skin or eyes, rinse thoroughly with plenty of water.
- If ingested, seek medical attention immediately.
- The product is non-flammable and is not considered hazardous to health or the environment.
Storage of Concrete Powder Shotcrete
- Shelf Life: 1 year in its original packaging.
- Storage Conditions: Keep away from freezing temperatures, excessive heat, and prolonged direct sunlight.
- Ideal Storage Temperature: 10+ to 30+ degrees Celsius.
Concrete Powder Shotcrete Packaging
- Packaging: 20 kg bags
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