Color material is blended with the concrete mix
to color the aggregate throughout. Many of the
colorants are iron oxides and can create colors
including blacks, yellows, and reds. Greens can
be achieved using chromium, and ultramarine can
be used to create variants of blue. Some of the
compounds used to create coloring are heavy metals
(including chromium) and can be released during
the grinding and polishing of the concrete. These
heavy metals can cause severe respiratory problems
and environmental damage.
New advancements in integral concrete color do
not utilize conventional iron oxide based pigments,
virtually eliminating efflouresence and alkali
discoloration by using "synthetic primary
pigments" SYPP. These synthetic primary pigments
are available in liquid emulsion form and are
highly concentrated for ease of use and economic
savings. SYPP are available in all primary colors.
SYPP are also blended with extenders and preservatives
to increase the color offering to include most
Rubber imprinting tools called "Stamps"
are impressed into wet concrete slabs or overlays
to create natural stone or brick textures. These
rubber imprinting tools are manufactured from
molds created from authentic stone or wood. Release
agents are used to help release the stamps from
the concrete without sticking. Release agents
come in either a liquid or powder form.
Items can be embedded in the concrete for practical
purposes (such as brass rails to serve as pot
holders on a countertop) or aesthetic ones (such
as decorating with shells or fossils).
Concrete "dyes" take many different
forms and compositions.
Early concrete dyes consisted of generic printing
inks that were dissolved in mild solutions of
alcohol and applied to concrete surfaces to add
a wide array of color to plain gray concrete.
When alcohol-based dyes are exposed to sunlight,
the color either lightens or fades out completely.
Therefore, alcohol-based dyes were more prevalent
in interior applications where direct sunlight
or other forms of ultraviolet (UV) lighting was
Manufacturers later began dissolving the same
printing inks in different carriers, such as acetone,
lacquer thinner and other solvents, hoping to
achieve increased penetration levels. In addition,
UV inhibiting agents were added to new dyes to
help with the UV instability issues. However,
fading still occurs when the dye is exposed to
Acid staining is not a dyeing or pigment-base
coloring systems, but a chemical reaction. A mixture
of water, salts and acid is applied to the concrete
surface and later neutralized by a basic solution
of ammonia and water. This chemical reaction with
the existing minerals in the concrete creates
new colors on the concrete surface. Due to inconsistencies
in the surface of concrete, acid staining creates
a variegated or mottled appearance that is unique
to each slab. The thickness of this color change
ranges from 1/16 to 1/32 of an inch. Exterior
concrete surfaces may not color as well as interior
surfaces because the environment has leached or
percolated out the mineral content.
Chemicals commonly used in acid staining include
Hydrochloric acid, Iron chloride and Sodium bicarbonate.
Water Based Stains are similar to acid based stains
in the sense that one can still achieve a translucent
look like acid; some stains are able to achieve
an opaque color and/or a translucent effect. The
main difference is that acid stains react to the
concrete and change the physical make up of the
concrete material, whereas water based stains
are more of a "coating" that bonds with
the concrete. There are many variations of water
based stains that have come into the decorative
concrete industry that perform in a number of
different ways. Some are polymer based, acrylic
Concrete overlays date to the 1960s when chemical
engineers from some of the larger, well known
chemical companies began to experiment with acrylic
paint resins as modifiers for cement and sand
mixes. The result was a thin cementitious topping
material that would adhere to concrete surfaces
and provide a newly resurfaced coating to restore
the worn surface. Concrete overlays lacked the
long term performance characteristics of acrylic
resins. Acrylic resins provided good UV resistance,
but lacked long term water resistance and adhesion
characteristics needed to provide a long term
and permanent solution.
Polymer cement overlays, consisting of a proprietary
blend of Portland cements, various aggregates
and proprietary hybrid polymer resins, were introduced
over 20 years ago. The purpose of adding a hybrid
polymer resin to the cement and aggregate is to
greatly increase the performance characteristics
and versatility of conventional cements, mortars
and concrete materials. Unlike conventional cement
and concrete mixes, polymer cement overlays can
be applied thinly or thickly without fear of delamination
or typical product failure. In addition, polymer
cement overlays are much more resistant to damage
from salt, petrochemicals, UV, harsh weather conditions
and traffic wearing.
Originally intended for use as a thin surface
restoration material for concrete substrates,
polymer cement overlays were introduced into the
architectural concrete and commercial flooring
industries in the early 80s. Subsequently, its
use in these industries has become standard. Polymer
cement overlays are regarded as economical in
providing long term, durable renovation without
the need for costly and continuous repairs associated
with deteriorating concrete surfaces.
Polymer cement overlays are used for interior
and exterior applications ranging from:
- a. Skim coat/broom finish concrete resurfacing
– Restore and protect damaged, pitted,
flaking and stained concrete back to the look
of a new concrete surface.
b. Concrete regrading & leveling –
Repair and level concrete surfaces that have
c. Existing substrate redecorating and renovating
– Alter the appearance of existing concrete
or wood substrates through applying "thin
stamped" or "thin stained" overlays,
creating new textures, colors and designs. For
use on commercial or resident pool deck, this
frequently takes the form of "splatter
textures" or "knockdowns," in
which polymer cement is applied to the existing
concrete substrate in a moderately textured
finish (average of 1/8” thickness) in
various patterns. Often, the texture is knocked
down with a trowel to slightly modify the appearance
and feel of the finished application.
Applied over acid stained and/or overlays to seal
and protect. Some epoxies are also colored.
Concrete can be polished with Mechanical grinders
and diamond pads of increasing grit sizes. Diamond
pads come in many grit or mesh sizes. Common sizes
start with 6 grit and can go up to 8500 grit although
concrete can only maintain a shine of about 800
grit, it can be helped by adding a concrete hardener
such as Sodium Silicate, Lithium Slicate which
will allow concrete to hold a 1800 through 3000
grit shine.The work is accomplished in multiple
stages by passing over the concrete with successive
grit diamond pads until it has a hard-glassy finish.
Both acid stains and concrete dyes can be used
during the polishing process.
Retrieved from "http://en.wikipedia.org/wiki/Decorative_concrete"