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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.
DeWulf Concrete of Los Angeles has recently introduced premade concrete slabs that are now available in Walker Zanger showrooms in southern California, and plan for national rollout in late 2007/early 2008. These products are more like the standard concrete countertop products in a slab form.
James DeWulf, owner of DeWulf Concrete and inventor of the process, stated in an interview with The Concrete Countertop Institute that the patented process/mix design was developed over two years and has been tested by an independent laboratory that found it had compressive strength of 20,000 psi and tensile strength of 2,200 psi. These are both much higher numbers than regular concrete. DeWulf's slabs are made 1 in. thick and 5 by 10 ft. in size.
Both Strugatz, DeWulf, and James Sheppard, president of Vetrazzo, expressed their dedication to the promotion of concrete countertops as a viable countertop surfacing option. They view the mass-manufacture of concrete slabs for fabrication as part of the continuum of methods for making beautiful, functional countertops and other elements out of concrete.
While the IceStone, Vetrazzo and DeWulf Concrete methods may be more familiar to solid surface fabricators, the vast majority of concrete countertops are custom-made. They are made from scratch out of sand, cement and aggregate in the final shape of the installation. To understand this process better, let's look at the steps involved. (These steps apply to precast manufacture. Another technique called cast in place involves pouring the concrete on-site.)
Template: This is done exactly like other countertop surfaces, usually with manual methods, to produce a full-size template.
Form: Forms made of melamine, wood, steel or foam are built around the templates on sturdy, flat and level casting tables. The forms are almost always built for upside-down casting.
Reinforce: Steel rebar or carbon fiber grid are arranged to sit in the bottom of the countertop (the top of the forms), to provide tensile strength to the concrete and prevent breakage.
Mix: The concrete is mixed either using a from-scratch recipe of sand, cement, aggregate and special chemical admixtures or using highly specialized concrete countertop mixes. Usually pigments are mixed in at this point to provide coloring.
Pour: The concrete is poured or placed into the forms. If custom embedments such as pieces of glass or metal are used, they are usually secured to the bottom of the forms and the concrete poured over them.
