Successful Floors

24 Steps To Successful Floors

Setting up, pouring and finishing a concrete floor doesn’t just happen. It takes some careful planning. And the more complicated the floor, the more planning. Factory and warehouse floors with high F numbers, steel reinforcing and toppings are a good example.

The following 24 steps to pouring successful floors are excerpted with permission from the January 2000 edition of Concrete International, the magazine of the American Concrete Institute.

  1. Conduct a preconstruction meeting to set up a well-executed installation and placement plan for slab-on-grade.
  2. Facilitate on-site communication between suppliers and contractors with continuous site visits by the consultants and the inspection/testing service.
  3. Select an experienced flooring contractor with a proven SFRC floor construction record.
  4. Require adherence to specified tolerances and reject defective products.
  5. Reduce cost without compromising quality and safety by improving the construction schedule.
  6. Insist on a clean work site with well-organized storage areas.
  7. Retain trained and responsive supervisors and coordinators and insist on field supervision by the general contractor.
  8. Coordinate on-time delivery of materials.
  9. Review joint details, placement size, and sequence of activities prior to scheduling each placement. Correct interferences and resolve site constraints before placing concrete.
  10. Optimize the concrete mixture on a quantitative basis to improve construction productivity as well as reduce cosUse 1½” (40mm) maximum coarse aggregate size and a 50-to-50 ratio of 1½” and 3/8″ (10mm) blend of coarse aggregates.
  11. Strive to obtain a consistent water-cementitious materials ratio (w/cm) of 0.45 plus or minus 0.02.
  12. Attempt to keep cement content consistent to reduce further adjustment to sand proportions.
  13. Achieve surface durability using trap rock, liquid sealer/hardener.
  14. Use SFRC to achieve higher concrete tensile strength, toughness, and ductility.
  15. Use the pinwheel contraction joint pattern to isolate columns and control irregular shrinkage cracks.
  16. Design fewer construction joints to reduce construction costs and to control curling at joints.
  17. Use a ½” (13mm) choker coarse lime screening as a slip-sheet between the slab-on-grade and the subgrade.
  18. Design using compactable granular subgrade material and appropriate thickness.
  19. Use 4000 psi (30 Mpa) concrete with minimum cement content of 560 1b/yd3 (330kg/m3), a 6-bag mix.
  20. Do not use fly ash in lieu of portland cement content in floor slab application.
  21. Maintain a smooth, well-graded and compacted subgrade and subbase surface.
  22. Allow sufficient mixing time between high-range, water-reducing admixture and steel fiber.
  23. Use a Laser Screed to obtain a flat and fiber-free surface, reduce the number of placements, and place larger areas.
  24. Insist on skilled operators and tradesmen utilizing new tools and maintained equipment.