Polypropylene fibers for mixing with concrete

PP fibers filler for micro crack prevention in concrete

Today it is very common to add polypropylene fibers into concrete for strengthening concrete and for protection of concrete against micro cracks. Most common count for this application is a  
PP dtex 2,2 with a relatively short cut of 12 mm. Other cuts used – but less common – are 8, 18 and 24 mm. The performance of PP in concrete is equally good as fiber glass, although the module of fiber glass is originally better. 

The function of the PP fiber mixed into concrete is not to replace the steel but to avoid the creation of micro cracks in the concrete.

 Consequences/results of applying PP fibers to concrete:

 Using PP fibers

avoiding micro cracks in concrete

nicely closed surface of concrete

less corrosion

longer life – higher long term stability of concrete  

• PP fibers are used in concrete to obtain a much better, more stable surface and more resistant piece of concrete. It reduces the danger of micro cracks dramatically. This increases the lifetime of this piece of concrete – especially true where this is exposed to changing weather conditions 
  
• The PP fibers should be mixed with the concrete only after the concrete is produced and very important it should immediately be used – with only very little movements on the truck – otherwise these fibers will be ground by the sand
  
• The length of the fiber should be min. 1,5 times the diameter of the sand particle – this is mainly true for the fine sands. With coarse sand particle diameters this comes down to 1 – 1,2 times
  
• Mixing of the fibers always to be as short as possible in order not to damage the fibers.
  
• The ratio of fibers depends on the requirement. It can vary from 1 – 5 kg / m3
  
• If transport from mixing plant to construction site is more that 2,5 hours then the mixing of the fiber should take place on the construction site
  
• The more PP fibers are mixed into the concrete the better the quality of the construction – anti micro cracks
  
• PP fibers do not replace the iron inside the concrete

More information on Anti Fire Crack and Micro Crack Preventer can be found here