Polypropylene fiber concrete
RIMSA's polymer fibers for concrete are synthetic macrofibers that provide residual strength once the concrete has cracked, in a role equivalent to that of steel fibers, with lower weight and no risk of corrosion. They can replace steel fibers in many applications —floors, lightweight precast elements and shotcrete— and are especially advantageous when corrosion, weight or surface finish are a concern.
Types of polymer fibers for concrete we offer
Steel fibers for concrete
The highest structural capacity. The choice when the aim is to replace conventional reinforcement in floors, slabs, tunnels and precast elements.
r glued · r wave eco · r hook · r glued HT · r smart
Glass fibers for concrete
Non-metallic reinforcement made of alkali-resistant glass, for when a clean surface finish is decisive.
r strand
Frequently asked questions about polypropylene fiber concrete
What is the difference between polymer microfibers and macrofibers?
Microfibers have a very small diameter and a low dosage: they act during the first hours of the concrete controlling plastic shrinkage cracking and improving the cohesion of the fresh mix. Macrofibers have a larger cross-section and length, and their function is structural: they provide residual strength once the concrete has cracked, in a role equivalent to that of steel fibers. They are not interchangeable: they solve different problems at different times.
Can polymer fibers replace steel fibers?
Polymer macrofibers can replace steel fibers in many applications —floors, lightweight precast elements, shotcrete— with clear advantages when corrosion, weight or surface finish are a concern. Their limit lies in the highest performance levels: for high residual strengths or thin sections, steel fiber is still more efficient. The comparison must always be made on equivalent performance and not on kilograms dosed, because the densities are very different.
Do polymer fibers affect the workability of concrete?
Yes, they reduce the slump, especially macrofibers at high dosages. It is a predictable effect and is corrected by adjusting the superplasticiser, not by adding water, which would penalise strength and durability. With the right dosage and mixing time, the concrete keeps normal placing and finishing.
Do polymer fibers improve fire behaviour?
Polypropylene microfibers are a recognised solution against explosive spalling in high-strength concrete exposed to fire: as they melt at a relatively low temperature they create a network of channels that releases the water vapour pressure inside the mass. It is a common requirement in tunnels and underground works.