When adding new concrete over old, dry concrete, the two will not bond together without a binder. A binding agent acts like the glue that holds the two unrelated layers together. You can use reinforcing bars to fix the new concrete to the old one if you want to prevent it from cracking. The most effective way to ensure that the bonding agent enters existing concrete is to apply it directly with a brush or rag. Even though it is possible to bond an old concrete to a new one, you should do it in the best way to prevent gaps or cracks from occurring.
If an existing concrete surface has grout (a dusty layer of cement and fine aggregates) or has been contaminated with spills such as oil or grease, the bonding agent will not work well. While it is possible to use old concrete as a base for new concrete, many factors will determine whether the concrete is strong enough to accommodate the new batch. When patching existing concrete, here's how to achieve a strong and durable bond between new and old concrete: First, clean the surface of any dirt, dust, or debris. Then, if you want to patch the concrete, apply a thin layer of cement paint, pour a well-mixed concrete patch into the holes and clean the surface with a wooden float. For this reason, you should use a very reliable concrete adhesive if you want to glue or bond two types of concrete together. Bonding adhesive will not work effectively if the concrete surface contains latitude (a dusty layer of fine aggregates and cement) or is contaminated with spills, including grease and oil.
For example, a new concrete building on a new gravel base will ensure that the structure is robust and can last up to 40 years. Although not the best option, adding a new layer of concrete over old concrete is still the next best option. However, if the old concrete is not in good condition, it will significantly reduce the life of your floors over time. I am repaving any cement driveway with Portland cement that has adhesive glue added. I got some areas where the mix didn't add herring to the entrance.
The patch or area where new concrete is added will rise compared to the rest of the house. Professional products backed by a national team of concrete experts can help you get every job done right. To ensure that your project is successful and long-lasting, follow these steps for bonding old and new concrete:
- Clean the surface of any dirt, dust or debris.
- Apply a thin layer of cement paint.
- Pour a well-mixed concrete patch into holes.
- Clean the surface with a wooden float.
- Use a reliable concrete adhesive.