¿What are synthetic fibers?
The synthetic fiber that are specifically designed for concrete are made from synthetic materials that can resist the alkaline environment of the concrete in the long run. These are added to the concrete before or during the mixing operation.
How do the synthetic fibers work in the concrete at an early age?
Volume changes of the concrete at an early age cause the formation of cracks and weakness due to the tensions that exceed the strength of the concrete at a specific moment. The growth of these fissures by contraction are prevented by the mechanical locking of the synthetic fibers. The internal support system of this synthetic fibers prevent the formation of cracks caused by plastic settlement.
The even distribution of the fibers throughout the concrete contributes to the no formation of large capillaries caused by the movement of water exudation (bleeding) up to the surface. The synthetic fibers reduce the permeability by combining both the reduction of plastic cracks and the decrease of capillarity by exudation.
How do the synthetic fibers work in hardened concrete?
The benefit of the use of synthetic fibers in the concrete at an early age continues in hardened concrete. The attributes of the hardened concrete given by the synthetic fibers are a reduction of permeability and a major resistance to the fracture, abrasion and impact forces.
The ability to withstand the forces which cause fragmentation or breakage of the concrete is remarkably improved by the use of synthetic fibres. When the concrete without fibers is put under compression, it will fracture and collapse after the first crack appears. The synthetic fibers manufactured specifically for concrete, prevent the effect caused by the shear forces, keeping the concrete strongly bound.
Due to the quantity of water exudation varying less when the synthetic fibers are use, the water/concrete proportion in the surface is more consistent, therefore it gets a major resistance to abrasion. This improvement is also due to the fact that synthetic fibers withstand the internal settlement, contributing to evenly maintain the exudation (bleeding).
The synthetic fibers reduce the cracking of the concrete caused by plastic shrinkage. This will improve its resistance to impact. The relatively low elasticity module of the synthetic fibers assists with the ability of the concrete to absorb shock or impact.
The synthetic fibers help the concrete develop its optimal long-term integrity by reducing both the plastic settlement and the formation of cracks due to shrinkage, decreases permeability and increases the resistance to abrasion, tear and impact forces. The synthetic fibers are compatible with all additives, silica fumes and cement chemistries.
Synthetic Fibers as secondary reinforcement?
The synthetic fibers that meet certain criteria regarding hardened concrete can be used as a non structural reinforcement by temperature or secondary reinforcement. These fibers can have documentation that confirms its ability to maintain the concrete strongly joined, after it has generated cracks.
The even distribution of the synthetic fibers throughout the entire concrete ensures the placement of the secondary reinforcement.