Shotcrete admixture type

Shotcrete admixtures are additives specifically designed to improve the performance and characteristics of shotcrete (shotcrete). According to their main functions and application areas, they can be divided into the following categories:

1. Rapid setting agent

Function :

Accelerate the setting and hardening process of sprayed concrete.

Application :

Suitable for projects that require rapid intensity development, such as tunnel construction, mining engineering, and slope stabilization.

Type :

• Alkaline accelerators : coagulate quickly but may cause durability issues and environmental impacts.

• Alkali-free accelerator : environmentally friendly, improves long-term strength, reduces contraction and cracking.

2. Plasticizers and superplasticizers

Function :

Improve the performance and fluidity of sprayed concrete while reducing water consumption.

Application :

Suitable for shotcrete projects that require high strength and low water-cement ratio.

Type :

• Ordinary plasticizer : medium degree of water reduction effect.

• High-efficiency water reducer : significantly reduces water consumption and provides excellent working performance.

3. Silicon powder

Function :

Improve the durability, strength, and cohesion of sprayed concrete.

Application :

Shotcrete used in underwater structures, tunnels, and high chemical exposure environments.

Advantages :

Reduce rebound loss and enhance substrate adhesion.

4. Retarder

Function :

Delay the setting time of sprayed concrete and extend the operable time.

Application :

Suitable for high-temperature environments or projects that require long-term transportation.

5. Air entraining agent

Function :

Introduce tiny bubbles into shotcrete to improve its freeze-thaw resistance.

Application :

Used in structures exposed to harsh climates or freeze-thaw environments.

6. Binder

Function :

Enhance the adhesion between new and old concrete or substrates.

Application :

Suitable for repair and reinforcement projects.

7. Water reducer

Function :

• Reduce the amount of water required for shotcrete to improve strength and durability.

Application :

Suitable for application scenarios that require high-performance shotcrete.

8. Anti-contraction additives

Function :

Reduce the risk of shrinkage and cracking of sprayed concrete.

Application :

Used for structures with high requirements for long-term dimensional stability.

9. Water-resistant admixture

Function :

Prevent cement and fine powder loss during underwater construction of sprayed concrete.

Application :

Suitable for marine engineering, dam and underwater restoration.

10. Preservatives

Function :

Protect embedded steel bars from corrosion.

Application :

Used for sprayed concrete in bridge decks, marine structures, and high chloride ion exposure environments.

How to choose the right admixture

When choosing a sprayed concrete admixture, the following factors need to be considered:

• Project requirements : strength, setting time, durability and environmental conditions.

• Construction method : wet spray or dry spray process.

• Substrate conditions : Existing concrete, rock or soil properties.

By combining different types of admixtures, optimal performance can be achieved for specific shotcrete applications.