Decorative concrete
Encyclopedia
Decorative concrete is the use of concrete as not simply a utilitarian medium for construction but as an aesthetic enhancement to a structure, while still serving its function as an integral part of the building itself such as floors, walls, driveways and patios.
The transformation of concrete into decorative concrete is achieved through the use of a variety of materials that may be applied during the pouring process or after the concrete is cured, these materials and/or systems include but are not limited to stamped concrete, acid staining, decorative overlays, polished concrete, concrete countertops, vertical overlays and more.
is the process of adding texture and color to concrete to make it resemble stone, brick, slate, cobblestone and many other products found in nature including wood, fossils, shells and many more. This limitless array of possibilities combined with great durability and lower cost than natural products makes Stamped Concrete an easy choice for new construction and renovation projects.
The installation consists of pressing molds into the concrete while the concrete is still in its plastic state. Color is achieved by using Dry Shakes or Color Hardeners, Powder or Liquid Releases, Integral Colors or Acid Stains. All these products may be combined to create even more intricate designs.
Stamped Concrete may be used on driveways, patios, commercial roads and parking lots and even interior floors.
Early concrete dyes consisted of generic printing ink
s 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 not present.
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, slight fading (5-8% per year) still occurs when the dye is exposed to direct sunlight.
staining is not a dyeing or pigment-base coloring systems, but a chemical reaction. A mixture of water
, mineral salts and a slight amount of muratic acid is applied to the concrete surface. This chemical reaction with the existing mineral
s (primarily lime) in the concrete over a period of one to four hours creates new earth tone colors on the concrete surface. The concrete surface is later scrubbed to remove excess stain and neutralized by a basic solution of ammonia
and water or baking soda (less likely to cause whiting later) to help raise the ph level back to normal level. Due to inconsistencies in the surface level of concrete floor, acid staining creates a variegated or mottled appearance that is unique to each slab. The color penetration ranges from 1/16 to 1/32 of an inch. Older exterior concrete surfaces may not color as well as interior surfaces because the environment has leached
or percolated
out the mineral content. As well, any exposed aggregate (rocks) in worn concrete will not accept staining.
Chemicals commonly used in acid staining include Hydrochloric acid
, Iron chloride
and Sodium bicarbonate
.
s date to the 1960s when chemical engineer
s from some of the larger, well known chemical companies began to experiment with acrylic paint
resin
s 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.
cement overlays, consisting of a proprietary blend of Portland cement
s, various aggregates and polymer resins, were introduced over 20 years ago. The purpose of adding a polymer resin to the cement and aggregate is to greatly increase the performance characteristics and versatility of conventional cements, mortar
s 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, petrochemical
s, 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:
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 or lithium silicate 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.
Geometric patterns, straight or curved lines and custom designs can be cut directly into the surface of the concrete creating the look of tile, flagstone, cobblestone and many other common surface patterns.
This is usually achieved using tools like an angle grinder fitted with diamond blades, but is more effectively accomplished using specialty tools designed specifically for cutting designs into the concrete.
Generally, this process starts with the sculptor, who creates the design to be used in the concrete using clay, polyurethane or wax. When the original art is complete, a cast is made using synthetic liquid rubber, and from this cast, form liners are produced in the reverse image of the original.
The form liner then acts as a mold for the concrete to be formed against. Once the concrete is set, the form liner is stripped from the hardened concrete surface. The concrete is permanently textured with the pattern of the form liner.
The transformation of concrete into decorative concrete is achieved through the use of a variety of materials that may be applied during the pouring process or after the concrete is cured, these materials and/or systems include but are not limited to stamped concrete, acid staining, decorative overlays, polished concrete, concrete countertops, vertical overlays and more.
Stamped Concrete
Stamped ConcreteStamped concrete
Stamped concrete is concrete that is patterned and/or textured or embossed to resemble brick, slate, flagstone, stone, tile, wood, and various other patterns and textures. Stamped concrete is commonly used for patios, sidewalks, driveways, pool decks, and interior flooring...
is the process of adding texture and color to concrete to make it resemble stone, brick, slate, cobblestone and many other products found in nature including wood, fossils, shells and many more. This limitless array of possibilities combined with great durability and lower cost than natural products makes Stamped Concrete an easy choice for new construction and renovation projects.
The installation consists of pressing molds into the concrete while the concrete is still in its plastic state. Color is achieved by using Dry Shakes or Color Hardeners, Powder or Liquid Releases, Integral Colors or Acid Stains. All these products may be combined to create even more intricate designs.
Stamped Concrete may be used on driveways, patios, commercial roads and parking lots and even interior floors.
Concrete dyes
Concrete "dyes" take many different forms and compositions and can be used on both residential and commercial concrete applications, including sound/retaining walls, bridges, countertops, floors, etc.Early concrete dyes consisted of generic printing ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...
s that were dissolved in mild solutions of alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
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
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
(UV) lighting was not present.
Manufacturers later began dissolving the same printing inks in different carriers, such as acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...
, lacquer
Lacquer
In a general sense, lacquer is a somewhat imprecise term for a clear or coloured varnish that dries by solvent evaporation and often a curing process as well that produces a hard, durable finish, in any sheen level from ultra matte to high gloss and that can be further polished as required...
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, slight fading (5-8% per year) still occurs when the dye is exposed to direct sunlight.
Acid Staining
AcidAcid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
staining is not a dyeing or pigment-base coloring systems, but a chemical reaction. A mixture of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
, mineral salts and a slight amount of muratic acid is applied to the concrete surface. This chemical reaction with the existing mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s (primarily lime) in the concrete over a period of one to four hours creates new earth tone colors on the concrete surface. The concrete surface is later scrubbed to remove excess stain and neutralized by a basic solution of ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
and water or baking soda (less likely to cause whiting later) to help raise the ph level back to normal level. Due to inconsistencies in the surface level of concrete floor, acid staining creates a variegated or mottled appearance that is unique to each slab. The color penetration ranges from 1/16 to 1/32 of an inch. Older exterior concrete surfaces may not color as well as interior surfaces because the environment has leached
Leaching (chemical science)
Leaching is the process of extracting minerals from a solid by dissolving them in a liquid, either in nature or through an industrial process. In the chemical processing industry, leaching has a variety of commercial applications, including separation of metal from ore using acid, and sugar from...
or percolated
Percolation
In physics, chemistry and materials science, percolation concerns the movement and filtering of fluids through porous materials...
out the mineral content. As well, any exposed aggregate (rocks) in worn concrete will not accept staining.
Chemicals commonly used in acid staining include Hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
, Iron chloride
Iron(III) chloride
Iron chloride, also called ferric chloride, is an industrial scale commodity chemical compound, with the formula FeCl3. The colour of iron chloride crystals depends on the viewing angle: by reflected light the crystals appear dark green, but by transmitted light they appear purple-red...
and Sodium bicarbonate
Sodium bicarbonate
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
.
Water Based Staining
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 and epoxy.1/4" Stamped Overlays
Rubber imprinting tools stamps are impressed into thin pre-mixed concrete overlay material 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.General Overlaying
Concrete overlayOverlay
Overlay may refer to:*Overlay architecture, term used to describe ‘event architecture’ and relates to the temporary elements that supplement existing buildings and infrastructure to enable the operation of major sporting events or festivals....
s date to the 1960s when chemical engineer
Chemical engineer
In the field of engineering, a chemical engineer is the profession in which one works principally in the chemical industry to convert basic raw materials into a variety of products, and deals with the design and operation of plants and equipment to perform such work...
s from some of the larger, well known chemical companies began to experiment with acrylic paint
Acrylic paint
Acrylic paint is fast drying paint containing pigment suspension in acrylic polymer emulsion. Acrylic paints can be diluted with water, but become water-resistant when dry...
resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
s 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
PolymerPolymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
cement overlays, consisting of a proprietary blend of Portland cement
Portland cement
Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout...
s, various aggregates and polymer resins, were introduced over 20 years ago. The purpose of adding a polymer resin to the cement and aggregate is to greatly increase the performance characteristics and versatility of conventional cements, mortar
Mortar (masonry)
Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...
s 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, petrochemical
Petrochemical
Petrochemicals are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as corn or sugar cane....
s, 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.
Applications
Polymer cement overlays are used for interior and exterior applications ranging from:
- Skim coat/broom finish concrete resurfacing – Restore and protect damaged, pitted, flaking and stained concrete back to the look of a new concrete surface.
- Concrete regrading & levelingConcrete levelingConcrete leveling is a procedure that attempts to correct an uneven concrete surface by altering the foundation that the surface sits upon. It is a cheaper alternative to having replacement concrete poured, and commonly performed at small businesses and private homes. In 1977, the term concrete...
– Repair and level concrete surfaces that have settled. - 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.
Epoxy
Applied over acid stained, dyes and/or overlays to seal and protect. Some epoxies are also colored.Polishing
Concrete can be polished with Mechanical grindersGrinding machine
A grinding machine, often shortened to grinder, is a machine tool used for grinding, which is a type of machining using an abrasive wheel as the cutting tool...
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 or lithium silicate 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.
Engraving
Existing concrete can be remodeled by cutting lines and grooves into its surface.Geometric patterns, straight or curved lines and custom designs can be cut directly into the surface of the concrete creating the look of tile, flagstone, cobblestone and many other common surface patterns.
This is usually achieved using tools like an angle grinder fitted with diamond blades, but is more effectively accomplished using specialty tools designed specifically for cutting designs into the concrete.
Form liner
Concrete can also be cast into unique and detailed designs using urethane form liner. These projects can be seen around the United States and the world, usually on sound/retaining walls, building exteriors, and bridges.Generally, this process starts with the sculptor, who creates the design to be used in the concrete using clay, polyurethane or wax. When the original art is complete, a cast is made using synthetic liquid rubber, and from this cast, form liners are produced in the reverse image of the original.
The form liner then acts as a mold for the concrete to be formed against. Once the concrete is set, the form liner is stripped from the hardened concrete surface. The concrete is permanently textured with the pattern of the form liner.