May 2016 HOW TO BUILD LASTING INDUSTRIAL CONCRETE FLOORS
Industrial concrete floors are typically constructed for heavy-duty purposes such as industrial and commercial floors, driveways and parking spaces, hardstand areas and cold room floors. We investigate the advantages and qualities of industrial concrete floors plus offer advice on how to build it sustainably and economically.
Top advantages of industrial concrete floors
As industrial concrete floors are high-performance floors, it poses a multitude of advantages for high performing commercial and industrial spaces:
Improved abrasion resistance, dimensional stability and ability of load transfer at saw cut joints. Decreased potential for plastic and drying shrinkage cracking. Lower risk of curling.
Most importantly, it requires lower maintenance costs in the long run
Minimum requirements of industrial floor concrete
Point of departure for building industrial floors is to use concrete that is specifically designed and manufactured for industrial purposes. It should also comply with the following minimum standards and requirements:
- Cement grade: Use concrete that has a minimum grade of 30 MPa for light duty industrial and commercial applications where there is heavy hard rubber wheeled traffic. This will improve the abrasion resistance and impermeability when power trowelled.
- Strength class: It is advisable to use a CEM I or CEM II cement with a minimum cement content of 310kg per m3 (Cubic Meter).
- Micro fibres: The concrete should ideally have an addition of 600g to 900g polypropylene micro fibres per 1 m3. This will make a significant difference in the reduction of bleeding and potential of plastic shrinkage cracking. It will further contribute towards increased impermeability as well as enhanced impact and abrasion resistance.
- Slump: The acceptable slump range for industrial floor concrete is between 50 to 100 mm with the aim to accomplish a target slump of 75 mm.
How to avoid typical issues with industrial concrete floors
Drying shrinkage is one of the major issues that affect the dimensional stability of concrete floors. The potential for drying shrinkage can be decreased by:
- Reducing the cement paste/aggregate ratio by using the maximum aggregate size and content.
- Using admixtures to reduce the water required for the mix even further.
Ideally, industrial concrete floors should achieve a drying shrinkage value of less than 0.05% – which equates to 0, 5 mm per 1 metre length.
Curling is another common problem. The potential for curling can be reduced substantially by taking the following factors into consideration:
- Thicker slabs are less likely to lift than thin slabs
- Panel sizes should not be greater than 30 times the slab thickness or 4,5 m Square, whichever is lesser
- Decrease the slab surface to the ratio of its thickness, ideally within 4x4m
Also important is to isolate the slab from structures such as walls, columns and manholes to reduce the slab restraint and level of induced stress. This will minimise cracking. If possible, also reduce any or all sudden differences in thickness of a slab, as this can also cause cracks.
Always take an uncompromising approach to quality
Taking shortcuts or using inferior products to save, will result in higher maintenance costs in the long run. Opt for a proven product like the Sephaku 42,5R. Manufactured by Sephaku Cement, it is fully compliant with the SANS 50197-1 specifications, which are minimum requirements for industrial floor concrete. Click here for more information or expert advice.