Corundum in Concrete Screeds: Instructions for Use and Grain Sizes

Corundum in Concrete Floors: Instructions for Use and Particle Sizes

In industrial and commercial environments, concrete floors are subject to constant wear due to heavy traffic, impacts, and abrasion. To increase their durability and resistance, the use of broadcast corundum on the concrete surface is a widely used technique. In this article, we explain how to apply corundum on concrete floors, which particle sizes are most suitable, and we offer you a step-by-step guide to optimize your flooring.

What is Corundum and why is it used in floors?

The corundum is an extremely hard mineral, composed of aluminum oxide (Al₂O₃), which is used in industrial applications for its high resistance to abrasion and wear. When applied to concrete floors, corundum reinforces the surface, making it more resistant to friction and impacts, which extends the useful life of the flooring.

Corundum is ideal for warehouses, industrial plants, workshops, and loading and unloading areas, where the concrete floor needs to withstand intensive use.

Corundum Particle Sizes Used in Floors

The particle size of corundum (the size of its particles) is crucial for obtaining the desired results. Depending on the finish and resistance sought, different grain sizes are used. Below, we indicate the most common particle sizes, translated into microns (µm) or millimeters (mm):

1. Fine Grain (125 to 180 microns / 0.125 to 0.18 mm):

   • Ideal for a smooth and uniform finish. It is used in floors where a high level of abrasion resistance is required without sacrificing aesthetics.
   • Medium-traffic and pedestrian areas.

2. Medium Grain (250 to 425 microns / 0.25 to 0.425 mm):

   • It is the most common particle size in industrial applications. It offers a balance between resistance and ease of application, perfect for heavy-traffic areas.
   • Warehouses, factories, and heavy machinery areas.

3. Coarse Grain (425 microns to 1,180 microns / 0.425 to 1.18 mm):

   • It is used when greater impact resistance is needed or when a non-slip surface is desired.
   • Ideal for outdoor areas or industrial zones with moist conditions or slip risks.

Corundum Application Manual for Concrete Floors

1. Concrete Preparation

Before applying corundum, it is essential to properly prepare the concrete slab:

• Pouring the concrete: Pour the concrete evenly over the surface. Make sure it is level and free of major defects.
• Initial smoothing: Use a screed or trowel to smooth the surface, ensuring a uniform thickness across the entire slab.

2. Determining the Application Time

Corundum must be applied at the right time, when the concrete is firm enough to withstand pressure, but still moist so the corundum adheres properly.

• Footprint test: When the slab can withstand slight pressure (leaving a light imprint), it is the right time to apply the corundum.

3. Applying the Corundum

Spread the corundum evenly over the surface of the fresh concrete.

• Amount of corundum: It is recommended to apply between 3 to 5 kg of corundum per square meter, depending on the desired level of resistance.
• Spreading: Use a shovel, hand hopper, or specialized equipment to ensure an even distribution of the corundum over the entire surface.

4. Integrating the Corundum

After sprinkling the corundum, it must be worked into the surface of the concrete.

• Power troweling: Use a mechanical or manual power trowel to press the corundum and make it adhere to the concrete. This process also smooths the surface and distributes the corundum better.
• If greater hardness is needed, a second layer of corundum can be applied and the power troweling repeated.

5. Final Smoothing

Once the corundum is fully integrated, perform a final smoothing to ensure a smooth and uniform surface.

• Steel trowel or roller: Use a steel trowel or roller to achieve a finer finish, which also helps close the pores of the concrete.

6. Concrete Curing

Curing is crucial to ensure that the concrete achieves maximum strength:

• Protection : Prevent the surface from drying too quickly. Protect the slab from wind and direct sunlight to avoid cracks.
• Curing time: Let the concrete cure properly. The minimum time is 7 days, but the concrete reaches its maximum strength in 28 days.

Benefits of Broadcast Corundum in Slabs

The use of corundum in concrete slabs has numerous benefits:

• Abrasion resistance: The hardness of corundum improves the slab's ability to withstand wear from heavy and continuous traffic.
• Greater durability: Extends the service life of slabs, reducing maintenance and repair costs.
• Slip-resistant surface: With the right particle size, it is possible to create a slip-resistant surface, perfect for areas with moisture or a risk of slipping.
• Versatility: You can adjust the type of corundum and the particle size according to the specific needs of your project.

Conclusion

The broadcast corundum is an efficient and proven technique for increasing the strength and durability of concrete slabs, especially in industrial and commercial environments. By selecting the appropriate particle size and following the correct application process, you can ensure that your slabs withstand wear, impact, and the most demanding conditions.

At Vetonek, we are committed to providing you with the best products and technical advice to ensure the success of your projects. If you have any questions or need more information about using corundum in concrete slabs, do not hesitate to contact us. We are here to help you!