Specification & Flatwork Needs
Polished Concrete is generally found under 03-35-50 Polished Concrete Floors under Cast In Place Concrete, but has also been specified under 09-62-00 Specialty Flooring. The polished concrete is the final floor finish for this structure. The aesthetic value of the floor is largely dependent on the flatwork that precedes it. Below are some recommendations to help ensure owner satisfaction.
Preferred Mix Design Specs
- 3500 psi minimum
- Pozzolans – No more than 15% cement replacement is recommended
- Admixtures – in moderation, admixtures are ok for use with polished concrete. Superplasticizers will require removal with a stripper before attempting to grind and polish.
- Keep mix designs for multiple pours as similar as possible.
- Do not use Calcium as it will affect the densifiers in the polishing process.
Preferred Flatwork Finishing Specs
- Preferred Floor Flatness (FF) of 50
- Preferred Floor Levelness (FL) of 45
- Strike off level with form, edges not to lift or slope
- Properly finish around edges and stick ups
- Well floated / well troweled
- No trowel marks
- Do not burn when power troweling
- No indentions left on surface (ex: knee marks, shoe prints)
- Bull-floated, smooth, pan-finished floor from edge to edge, with no rough areas
- Concrete Compressive Strength: 3,500psi to 5,000psi
- Lightweight Concrete: Not allowed if aggregate exposure is required.
- Concrete Curing: Minimum 8 days water cured or dissipating curing compound applied.
- Laser screeding is good for ensuring flatness.
- Minimum 28 day cure time
- Wet cure with curing blankets is preferred
- Blankets must be pulled 5 days prior to the polish
- If cure and seal is necessary; use only dissipating cure and seal