With PolishedCrete, making concrete polished is what we do every day and although no concrete is the same, the process we employ is the same and is like sanding wood to a fine and smooth surface. We begin by opening and grinding the surface with a very course abrasive (using low-grit, diamond tipped abrasive pads). Then we use progressively finer grit abrasives (we might start with 10 grit and may go into the thousands depending on the gloss finish the client wants). The process will also be impacted by the concrete slab you are working on and the quality of the diamond pads as well.
At a certain step in the process, a densifier (densifying chemical) is applied that makes the concrete extremely dense and closes nanometer-sized holes in the concrete. The process may be done wet or dry except for the application of the densifier which is a liquid.
Dust from the grinding and polishing is kept to a minimum through the use of powerful vacuums that attach right to the grinding hub.
There are four classes or visual facets of polished concrete (depending on the quality and levelness of the slab):
• Cream – little to no aggregate exposures
• Fine Aggregate – fine aggregate exposure or sand tips with little or no medium aggregate exposure at random locations
• Medium Aggregate – medium sized aggregate (small rocks) exposure with little or no large aggregate showing
• Large Aggregate – Large aggregate exposure with little or no fine aggregate exposure at random locations
Concrete polishing is the mechanical refinement of the concrete surface to its purest form with diamond abrasives therefore any imperfections in the slab such as lack of uniform aggregate, unevenness, exposure of various embedded aggregate sizes, etc. will impact the final look.
We always recommend adding a final a protective, penetrating guard on newly polished concrete. This gives surfaces a higher gloss, increased abrasion and stain resistance as the new surface continues to harden and densify. Burnishing the surface using a diamond impregnated pad will create a high gloss finish with excellent wear and properties and extended life while lowering maintenance costs.