WHY Use Synthetic Fibers?
Synthetic fibers benefit the concrete in both the plastic
and hardened state. Some of the benefits include:
- reduce plastic settlement cracks
- reduce plastic shrinkage cracks
- lowerr permeability
- increased impact and abrasion resistance
- providing shatter resistance
Some synthetic fibers maybe used as secondary reinforcement
(Hardened Concrete Performace Documentation Required)
HOW do Synthetic Fibers Work in Early Age Concrete?
Early age volume changes in concrete cause weakened
planes and cracks to form because a stress exists
which exceeds the strength of the concrete at a specific
time. The growth of these micro shrinkage cracks
is inhibited by mechanical blocking action of the
synthetic fibers. The internal support system of the
synthetic fibers inhibits the formation of plastic settlement
cracks. The uniform distribution of fibers
throughout the concrete discourages the development
of large capillaries caused by bleed water migration
to the surface. Synthetic fibers lower permeability
through the combination of plastic crack reduction and
reduced bleeding characteristics.
How Do Synthetic Fibers Work in Hardened Concrete?
The early age concrete benefits of using synthetic
fibers continue to contribute to the hardened concrete.
Hardened concrete attributes provided by synthetic
fibers are lowered permeability and the resistance to
shattering, abrasion, and impact forces.
The ability to resist shattering forces is greatly enhanced
with the introduction of synthetic fibers to the
concrete. When plain concrete is compressed, it will
shatter and fail at first crack. Synthetic fibers manufactured
specifically for concrete prevent the effect
of shattering forces by tightly holding the concrete
together.
Abrasion resistance is provided when synthetic fibers
are used because the water-cement ratio at the
surface is not lowered by variable bleed water. The
water-cement ratio is more constant at the concrete
surface. This improvement is assisted by the internal
settlement support value of the synthetic fibers
contributing to uniform bleeding.
Synthetic fibers reduce the amount of plastic cracking
of the concrete. This improves the impact resistance
of concrete. The relatively low modulus of the
synthetic fibers provides shock absorption characteristics.
Synthetic fibers help the concrete develop its
optimum long-term integrity by the reduction of
plastic settlement and shrinkage crack formation,
lowered permeability, and increased resistance to
abrading, shattering, and impact forces. Synthetic
fibers are compatible with all admixtures, silica fumes,
and cement chemistries.
How are Synthetic Fibers Used as Secondary Reinforcement?
Synthetic fibers which meet certain hardened concrete
criteria can be used as nonstructural temperature or
secondary reinforcement. These fibers should have
documentation confirming their ability to hold concrete
together after cracking.
The uniform distribution of synthetic fibers throughout
the concrete ensures the critical positioning of secondary
reinforcement.
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