Updated: March 21, 2024

Concrete is made up of three basic components: water, fine aggregates such as sand, gravel, or rock, and cement. When mixed, these components create a construction material that hardens (cures) over time. Well-laid concrete provides a hard and durable surface that can withstand nature’s normal deteriorating mechanisms.

That being said, severe exposure conditions, poor design and construction practices, and material limitations can cause concrete to deteriorate. The chances are that the damage is superficial, and your concrete surface is still structurally sound, in which case you need to patch it. You can patch concrete by pouring new concrete over old concrete. 

The problem is that dried concrete has no natural bonding agents and won’t bond or stick well on another concrete material. You’ll need a bonding adhesive to get wet concrete to bond to existing concrete. Read on to learn how to bond concrete to concrete. You can also learn more about our parent company Adhesives Technology Corporation

Repair or Replace?

If cracks and other surface defects are not repaired correctly, the damage will only get worse. Sometimes the best solution is to replace the entire slab. The key to determining whether you need to repair or replace a concrete slab is to determine if it is structurally sound. If the cracks are too deep and appear to run through the surface, it’s best to replace the entire surface.

Choose a Bonding Method

When it comes to bonding cement-based products to existing concrete, there are two methods. You can use mechanical bonding or chemical bonding. Mechanical bonding is formed by the penetration of the repaired product into the pores of the old surface, achieving a mechanical interlock. 

Mix the repaired product with water to make a scratch coat, then apply more repair material over the scratch coat to create a mechanical bond. Chemical bonding involves using a liquid bonding agent to stick new concrete to the surface of old concrete. Apply the bonding agent to existing concrete and let it dry before applying the repair material. 

Wet the Surface

Use a hose attachment to sprinkle water evenly on the existing concrete. Stop right before you start creating standing water on the surface. Wetting the old concrete surface will help prevent it from sucking water from the repair material. This step is only necessary if the area is too large for a scratch coat. 

Check Your Work

An important step in learning how to bond concrete to concrete is checking your work to see if the bond was successful. Wait at least 24 hours, gently tap the patch using a dull object such as a hammer, and listen. The hollow sound you get when hammer tapping delaminated concrete indicates an unbonded concrete layer between the slab body and the paste layer at the surface.

Options for Concrete Adhesive at Affyx™

Now that you know how to bond concrete to concrete, it’s time to go shopping for a bonding agent. Concrete won’t bond to another concrete material if you don’t apply an effective concrete adhesive. With the right concrete adhesive, your concrete repairs can stand the test of time. Nobody knows more about private label adhesives manufacturing than AFFYX™. 

If you are looking to bond two concrete surfaces together and need a high-quality product to get the job done, look no further than Affyx™. We have a wide range of construction adhesive products that can be found on job sites and in retail stores all across North America.

Shop the Best Concrete Adhesives

Concrete is one of the most robust and most durable construction materials. However, cracks and other surface defects can occur due to a combination of factors. The good news is that you can always resurface the existing concrete. However, bonding concrete to concrete requires a bonding agent. Shop the best concrete adhesives at Affyx™ today for long-lasting results. Contact us for any inquiries!