Flaws Are Repaired
Before polishing a concrete floor, cracks, chips, and surface wear are repaired using a concrete crack repair kit. Crack repair materials include polyurethane, which is a polymer that expands to fill cracks and chips completely as it cures. This ensures that the material adheres to the concrete so that the patch does not fall off. Moreover, this squeezes out any air bubbles between the concrete and repair material that might weaken the patch.
Stains and surface wear are repaired during the polishing process. Polishing pads that include resin diamond abrasive or metal bond diamond abrasive remove a thin layer of the concrete as they polish it. Since stains and surface abrasion typically do not penetrate the concrete, the grinding and polishing process is sufficient to remove them.
Surface is Hardened
Concrete is a cheap building material. In fact, over 7 billion cubic meters of concrete are produced every year throughout the world. However, concrete is notorious for being strong in compression, but weak in tension. In normal circumstances, tension makes concrete crack and crumble.
A key part of strengthening polishing concrete is the concrete filler. Concrete filler contains minerals, such as silicates, and polymer resin. The result of grinding the concrete filler into the concrete is that any surface pores are filled with the concrete filler, thereby increasing the density of the concrete surface. Moreover, because the concrete filler contains resins, the surface layer created is hard, like plastic. But most importantly, this surface layer provides tensile strength to the concrete. Plastic, like polymer resins in concrete filler, are strong in tension.
Here is an analogy – take a plastic straw and pull on the ends. It is very strong in tension. Even if it breaks, it will stretch a lot before doing so. If this straw is used to reinforce something, like a cookie, it will tend to hold the cookie together and prevent it from cracking and crumbling.
The resinous surface layer created by cured concrete filler acts in the same way. It reinforces the concrete and works against concrete’s natural tendency to crack and crumble.
Surface is Smoothed
The multiple passes over the concrete floor’s surface with polishing pads of varying grit results in a smooth, polished surface. Aside from the aesthetic benefits, there are two functional benefits:
- Reduced tread wear. Intuitively, a smooth surface will wear tire and shoe treads less than a rough surface. When used in high traffic areas, polished concrete will save you and your employees money by reducing tire and shoe tread wear.
- Increased traction. Non-intuitively, a polished concrete floor provides greater traction when dry than ordinary concrete. There are two theories for this. First, the concrete filler contains resins. Since resins are plastic, they provide grip to the polished floor. Second, the smooth surface provides greater surface contact, thereby providing more surface to grip than a rough surface does.
Polished concrete floors reflect light better than unpolished concrete floors. Under some circumstances, this is an aesthetic difference. However, in many cases, this provides a significant functional advantage. For example, in a hospital or restaurant kitchen, good lighting is essential for safety. Having a floor that reflects light back into the room or hallway can help people spot obstacles and slippery areas before they cause an injury.
When used in warehouses, particularly warehouses with high ceilings, the overhead lights may be quite distant from the work floor. A reflective floor can provide a better illuminated work area. It may even help conserve electricity since it may be possible to replace high intensity lights, such as halogen bulbs, with lower intensity lights while maintaining or improving overall illumination.
Polished concrete floors provide both aesthetic and functional benefits over unpolished concrete. These benefits include a harder, smoother, and more reflective surface without cracks, chips, or surface wear.