Weststyle, the lead architect on this project, came to DS Grinding requesting a mechanically polished concrete with nil exposure on a burnished finished slab. This was then elevated to be a custom black concrete mix to be poured and burnished prior to mechanically polishing.
The Brief: Black, raw/natural looking concrete that has the mechanical polished process applied to it, but looking as a uniform finished product on completion. In order to attempt to get uniform color, project design was centered around being able to achieve larger pour areas and being able to burnish evenly throughout what was a tight, multistory construction area.
Once placed and cured, DS Grinding used a range of nil exposure/burnished polishing pads known as B-Type Pads provided by Carbon Diamond Abrasives under the Lavina propane machines to create an even sheen throughout without removing the burnished layer of concrete. The process was done wet to minimize pattern scratching and Epimax 2025 was the initial stage potassium-blend densifier used to create a hardened canvas almost immediately to prevent surface stock removal.
Once the mechanical polish was completed, the challenge then was to work on the 'unburnished' edges where the power trowel could not darken the slab during construction. These edges were almost white in comparison to the majority of the burnished black slab. DS Grinding and Weststyle worked together with Lithofin Australia. After a range of tests and sampling, Lithofin created a unique blend of their Stainstop product and CCS oxide to manually treat and darken the edges at the perimeter of the internal edges where the color issues were apparent. The end result overall was a stunning finish that met the brief of the architect and Weststyle alike. The color variations throughout were blended to keep the unique natural burnished look but within the same color expectation and the mechanical polished process was evenly performed throughout.