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Forming grids for laying the concrete
An integral concrete sink in a countertop is created using a "hand pressed" technique with a stiff concrete mix.
Concrete is being mixed in a paddle style mixer.
In this process the concrete surface is going through wet grinding with diamond tooling.
The terra cotta orange concrete has embedded metal gears with blue concrete inside them.
A wine glass stem has been embedded in this concrete surface.
A sleek, contemporary kitchen with soft gray countertop and full-height backsplash.
Concrete countertops share many of the characteristics of solid surface countertops. They are versatile, durable and offer a wide range of colors, textures, finishes and limitless design possibilities. They even allow for integrally molded sinks as well as backsplashes and seamless installations.
However, the manufacturing and fabrication process, and many of the performance characteristics of concrete countertops, differ widely from solid surface materials.
Process
Concrete countertops are not usually fabricated in the traditional sense of cutting and shaping blank slabs to fit an application. Although there are a few companies manufacturing blank slabs of concrete and selling them to fabricators, this can present challenges for two reasons:
First, concrete must cure to obtain full strength, making transportation soon after manufacture risky. Concrete almost always needs to be structurally reinforced to prevent breakage. A good way to do this is through the use of steel or carbon rebar-like material embedded in the concrete. This makes for a nonuniform look once the slabs are cut. A few companies have solved this problem with highly specialized mix designs that boost both compressive (hardness) and tensile strength (resistance to breakage and reduction of brittleness).
Second, cutting concrete presents challenges different than those for solid surface or natural stone. Some diamond cutting and grinding tools used for granite are inappropriate for concrete because concrete is extremely abrasive — it has hard sand grains and aggregate embedded in soft cement. Adding fabrication of concrete slabs to a solid surface and/or granite fabrication shop would require at least some new tooling more suited to the material to prevent wear on the tooling. However, if only a few concrete slabs are cut, the wear could be negligible. Concrete slabs specifically manufactured for fabrication tend to have a harder cement matrix that is less abrasive to diamond tooling.
These concrete slab products use the same basic fabrication equipment as that used to fabricate granite or quartz surfacing — bridge saws, edge grinders, etc. — and the product requires sealing at about the same frequency as granite.
There are at least three companies that have addressed the fabrication challenges and sell premade slabs of concrete designed to be fabricated by traditional granite fabrication tooling: IceStone, Vetrazzo and DeWulf Concrete.
IceStone and Vetrazzo focus on the environmental sustainability of their products. These materials are made from recycled glass and concrete, and are seeking to be the top choice for green countertops. Both products reduce the waste stream by using glass from landfills as aggregate.
Peter Strugatz, owner of IceStone, spoke with The Concrete Countertop Institute recently about his dedication to "high design in green" and to economic development, such as hiring workers locally from high unemployment areas.
