A Scientific Approach to Polishing Concrete

One of the issues I see in the concrete polishing industry is contractors not allowing an abrasive to fully refine the floor to its maximum potential before moving to the next grit in the processing sequence. The result is a floor that lacks overhead reflective clarity and durability.

So how does a contractor know when an abrasive has refined the surface to its fullest potential? How does an owner, architect and general contractor bid a job and receive apples-to-apples bids where finished results will be the same regardless if they choose contractor A or B?

I often wonder why the concrete polishing industry tries to reinvent the wheel. Materials have been processed with abrasives for more than 100 years. For example, optical lenses — eye glasses — are polished with abrasives. I believe we should look to other industries already processing material to a specified finish to help improve our industry. What you will find is the challenges they deal with are the same issues the concrete polishing industry is dealing with.

Customers often request a specific polished concrete finish such as honed, semi-polished, highly polished or mirrored polished. These terms are based on visual aesthetics and may have different meanings from one person to another. In other words, these definitions are subjective. If a customer requests a highly polished concrete floor, that finish will range in reflective appearances depending on the contractor and to what degree he allowed the abrasives to fully refine the floor throughout the grit sequence.

The concrete polishing industry attempted to combat this subjectivity by utilizing gloss meters. The industry quickly found gloss readings could be improved by applying chemicals, and at times higher readings were often a result of resin transfer from resin-bonded abrasives.

What if we could remove some of the human element of subjectivity with an instrument that could provide a scratch profile reading that would tell the contractor and owner the floor has been refined by the diamond abrasives to a specified degree from one grit to the next? This could allow for the creation of refinement categories which would allow for different qualities of polish through a scientific approach. Each category would inherently have its own degree of reflective clarity and durability.

For example, if working on a top tier project like a school floor, what I will call a refinement category Class A finish, you would want a measurable degree of refinement from one grit to the next. A Class A floor would require a reading that shows a high level of refinement. Let’s say we are working in a warehouse where the owner may only want a low-grade polished concrete finish, what I will call a refinement category Class C finish. This would mean each grit would require a lower degree of refinement. The result would be less reflective clarity and lower durability but would fit the owner’s needs and budget. Both examples could be produced using scientific means.

Scientific data could be used to show increase in abrasion resistance between refinement categories. The concrete being worked on will be a determining factor in overall abrasion resistance, but the process itself creates its own percentage level of increased or decreased abrasion resistance. For example, the abrasion level of any unprocessed material is going to be X; after the polishing process is performed the new abrasion level is Y. The increase in abrasion resistance is going to be the difference between X and Y expressed as a percentage.

Slip coefficient? This data will also provide end users assurance that when the floor is installed to meet specific surface roughness criteria they will have a floor that meets specific slip coefficient requirements.

A means of measurement