Polished concrete, discovered about 14
years ago and has taken its path to history as a sustainable and
low-maintenance paving option in almost all market segments. We have all walked
on a polished concrete surface in recent years. It is such a popular and
fast-growing sector that, in many cases, is outperforming consumers and
contractors with new technologies and new methods. This rapid growth has put
the industry in a very volatile state, leaving consumers confused about what is
and what is not polished and what aspects of performance to expect. (Burns, 2015)
The Concrete Polishing Association of America (CPAA) was formed in
November 2009 to create standards for concrete processing with a glossy finish
and help define these processes so that architects, designers and consumers can
better understand the selection process. CPAA’s leadership consists of manufacturers
and contractors to provide continuity in the creation of these standards and
The CPAA defined polished concrete as;
“The act of changing a concrete floor surface, with or without additional
exposure, to achieve the desired level of glossy finish”. There are three
types of polished concrete according to the CPAA. They are abrasive polishes
bonded to concrete, burnished polished concrete and topically polished
“polishing process” can divided into three sections. Those are grinding,
densifying and polishing. (wine, n.d.)
There are many flooring systems in the
market and big competition also there. So, evaluation and made modification
should need to polished concrete for survive in industry.
considering floor restoration, that not all types of flooring will be similar
to glass. Concrete grinding occurs before the polishing process, making it a
simpler option and one that takes less time when ultra-bright surfaces are not
required. The resulting grinding texture is a gritty abrasive that is halfway
between an opaque appearance and a low-level gloss, a classic appearance of
steps or exterior surfaces.
The rectified cement can also be
sealed with a urethane sealant to achieve a finish similar to cement smoothed
in fewer steps. In fact, a floor sealed with urethane can work better in many
environments than a polished floor.
Since concrete processing is a
series of steps, the level of resistance, durability and brightness improves as
much as you cut and remodels the concrete. This is the reason why the ground
cement is not as bright as its polished counterparts; polishing requires a
significantly higher production. Both, however, offer a professional look, so
the type of concrete we choose depends entirely on our preferences. (O’Shannessy,
Figure 2 – Grinding Steps different exposes of Aggregate (polished-concrete-the-complete-guide-2017, n.d.)
Sand / Cream Finish
of light sand is a polished, polished surface that, as a rule, expands sand
particles onto the concrete floor. This finish is considered a
“creamy-looking” surface and is the most popular choice for polished
floors and architectural floors.
Salt & Pepper Finish
of salt and pepper is a smooth and polished surface, which usually exposes a
fine-grained spray to the concrete floor. This finish is chosen more often to
give the appearance of the old surface. The cutting depth of the surface is
· Medium Aggregate Finish
exposure of the population as a whole ensures the greatest amount of the
average aggregate in a concrete floor with a low or no aggregate impact in
random places. Approximate cutting depth of the surface is 1/8 of an inch.
· Large Aggregate Finish
Large aggregate exposure is a more “cut” surface, which usually exposes the largest amount of the largest aggregate in the concrete floor. Finishing is preferable when the substrate has been planted using tuned aggregates. On some floors, including the restoration of the old concrete, there may be limitations in the depth of cut of the floor. The cutting depth is 1/4 inch.
begins with a 50-grain resin pad, which is quite aggressive and can be used to
expose the small aggregate slightly. The scratches and grooves were left with a
50-grain resin pad.
refers to smoothing and removing scratches and generally involves the use of
50, 100 and 200 grain discs.
surface with a 200-gram pad is smooth, scratch-free and totally opaque or
glossy. There may be vortexes on the surface, but there are no deep scratches.
The injection usually takes place after the passage of 200 grains: a 200 grit
is not aggressive enough to cut into the concrete and open more holes, but a
200 grit is aggressive enough to cut the hardened mortar.
of salt and pepper refers only to the exposed grains of sand. Often, this aspect
can be achieved by removing the cement cream with a 200-grained buffer in one
step, exposing the cement paste matrix.
Densifiers are used to harden the concrete substrate. This is useful in several
aspects. First of all the hard cement is easier to polish and made a glossy
finish. Secondly, a harder concrete substrate works better as a flooring
option. The densifiers are complicated to understand but relatively easy to
use. The densifiers normally consist of lithium, sodium silicate or potassium.
The sodium portion, lithium of the chemical composition is used to transfer the
silicate to the concrete. When the silicate meets calcium hydroxide, which is
commonly known as free lime, located within the concrete substrate, it
transforms and creates a crystalline structure. This crystalline structure
helps to add resistance and abrasion resistance to the concrete surface. When the seal is added
to the concrete during polishing, it is better dictated by the concrete itself.
If the concrete is soft and porous, the use of significantly thickeners during
the process would be very useful.
This would help the polishing technician
achieve maximum refinement with diamond tools. However, if the concrete
substrate has a high structural strength, it has been finished on a hard and
dense surface, so a small additional densifier would have been required. Most densifiers
react with cement in the same way creating a harder and dense surface. (Harris., n.d.)