10 Things You Need to Know About Silica Fume in Ready-Mixed Concrete

Silica fume is a highly-effective supplementary cementitious material that has been in use since the 1970s. It is used to enhance the properties of ready-mixed concrete. In this article, we will look at the 10 key considerations you need to keep in mind when using silica fume in ready-mixed concrete.

1. Silica Fume and its Properties.

Silica fume is a by-product of the production of silicon metal and is obtained through the reduction of high-purity quartz with coal or coke in electric furnaces. It is a finely divided, amorphous, and highly reactive material with a high surface area, which gives it excellent pozzolanic properties.

2. Benefits of Silica Fume.

Silica fume has numerous benefits when used in ready-mixed concrete. It enhances compressive strength, durability, resistance to chloride ion penetration, and reduces permeability and alkali-silica reactivity (ASR).

3. Use of Silica Fume in Concrete Mix Design.

Silica fume is added to concrete during the mixing stage and is typically dosed at 5-10% by weight of cementitious material. Its dosage can vary depending on the desired properties of the concrete.

4. Effect of Silica Fume on Fresh Concrete Properties.

Silica fume affects the properties of fresh concrete by decreasing the water demand, increasing the viscosity, and reducing the workability of the mix. However, superplasticizers can be used to improve the workability.

5. Effect of Silica Fume on Hardened Concrete Properties.

Silica fume enhances the properties of hardened concrete by reducing the porosity, increasing the strength and stiffness of the mix, and improving its durability.

6. Curing of Silica Fume Concrete.

Silica fume concrete requires proper curing to achieve its full potential. It should be moist-cured for a minimum of 7 days or until it reaches 70% of its design strength.

7. Silica Fume and Its Effects on Air Content.

Silica fume reduces the air content of concrete due to its high fineness. Proper admixture dosing can be used to achieve the desired air content.

8. Silica Fume Quality Control.

Silica fume should conform to ASTM C1240 or any other applicable standards to ensure its quality. The physical, chemical, and pozzolanic properties of the material should be tested regularly.

9. Storage and Handling of Silica Fume.

Silica fume should be stored in a dry and well-ventilated place. It should be handled with care to prevent dust from becoming airborne.

10. Cost of Silica Fume.

The cost of silica fume can vary depending on the source, transport, and dosage required. However, the many benefits of using silica fume can significantly outweigh its cost.

Whether you are an engineer, contractor, or a homeowner, understanding the properties and benefits of silica fume is essential when using it in ready-mixed concrete. Proper mix design, handling and quality control are critical to ensure that concrete meets the desired specifications. Contact us to learn more about how silica fume can enhance your next concrete project.

Contact us to discuss your requirements of Silica Fume in Ready-Mixed Concrete, China Silica Fume in High Strength Concrete, China Silica Fume in Brick Factories. Our experienced sales team can help you identify the options that best suit your needs.