The Polished concrete industry
Polished concrete is concrete that has been processed or refined through a series of mechanically ground "polishing/grinding" steps utilizing professional equipment designed for concrete polishing. This process also includes the use of a penetrating chemical known as a densifier. The concrete densifier/hardener penetrates into the concrete and creates a chemical reaction to help harden and dust proof the surface. During concrete polishing the surface is processed through a series of steps (in general a minimum of 6 steps is considered polished concrete) utilizing progressively finer grinding tools. The grinding tools are progressive grits of industrial diamonds in a bonded material such as metal/hybrid/resin often referred to as diamond polishing pads. we can do anything from a cream finish which has no aggregate exposure right to a full aggregate exposure which shows all of the stones in the concrete surface. We can do either a matte finish, semi-gloss or a high gloss finish which is extremely shiny and reflective. Dyes designed for concrete polishing are often applied to add color to polished concrete as well as other options such as scoring, creating radial lines, grids, bands, borders, and other designs for example business loggos which are in the concrete surface. Polished concrete is considered a good sustainable design flooring option because it makes use of the materials already present. Most modern buildings are built on a concrete slab; polishing the exposed concrete eliminates the energy and additional material costs consumed by applying a floor covering. It is something to consider when building or modernizing towards a more green solution.
Polished concrete floors are considered low-maintenance, as they are more durable and easier to clean than many flooring options. Its high coefficient of friction can make it non-slippery. Polished concrete reduces dust mite and allergen problems, and does not support mold growth. Anecdotal evidence suggests highly reflective polished concrete reduces lighting needs and can improve natural lighting. Polished concrete flooring is hard wearing and will not chip or dent like softer surfaces such as timber and tiles. Polished concrete is easily maintained with the use of clean water or a neutral balance PH cleaner. There are also many cleaners designed for the proper maintenance of polished concrete available. There is never a need for wax to be added as it will only dull the finish. A concrete floor that has been hardened and polished will have an extremely long life expectancy compared to other flooring.
For example, Epoxy has a short life span of 1 to 5 years and can easily peel or delaminate from the concrete substrate, some tile floors may only last 10–20 years, but a polished concrete floor that has been properly maintained may give 30+ years of service.
In simple terms, the process of polishing concrete is similar to sanding wood. Heavy-duty polishing machines, for example concrete grinder, are used to gradually grind down surfaces to the desired degree of shine and smoothness. The closest equivalent example would be polished granite or marble.
Polished concrete floor installation is categorized into two types: new floors, and retrofit floors.
New floors
New floors require less work resulting in lower costs, but there are a few things to be aware of before a new concrete floor can be polished. Firstly the mix design of the concrete should be 3,500 psi or higher. The concrete should always be poured full depth to take advantage of the concretes full structural strength and to also help in preventing cracks. The concrete should always be professionally finished with power trowels and properly cured with water for 7 days. Polishing should not begin to the concrete is full cured (generally 28 days). The concrete slab can contain decorative aggregates to create many different aesthetically beautiful appearances. The concrete aggregate is typically the normal aggregates used in the region, but almost anything can be used. The finished surface of the concrete will need to be finished to a high standard to facilitate the polishing process. According to the Global Concrete Polishing Institute, a FF (floor flatness level) of 50 or greater is desired. During the finishing phase any decorative aggregates such as seashells, glass chips or even metal car parts can be dropped into the surface of the concrete. Builder needs to be aware as early as possible if the concrete is to be polished so that the final finish is of the best quality.
Retrofit floors
Retrofit floors can be done in different ways depending on the conditions of the concrete. If the existing concrete is in good condition the surface can be polished to just about any standard. If the existing floor slab is in poor condition it can be cut or grinded and the natural aggregate can be featured as the "exposure level". If the exsiting suface is in very poor condition a topping slab with a minimum thickness of 50 mm (2 inches) can be added on top of the existing slab.