|
|
|
Applications : GFRC Replacement
For many years international manufacturers of curtain walls have chosen PVA over AR glass. Companies like Eternit, Kajima and FRC recognized over a decade ago the advantages that PVA fibers have for external roof and wall cladding. Light weight, a strength-to-weight ratio greater than AR glass, and the comfort of knowing that PVA won't degrade in highly alkali cement, decade after decade. What's more, PVA fibers save money compared to AR glass. A typical glass-reinforced panel will use up to 5% glass by weight of the total panel. A similar PVA panel uses only 1.4% of similarly priced fibers. Yet this smaller amount of PVA fibers will deliver strain-hardening, the ability to absorb many times the amount of energy before failure than can GFRC panels. PVA fibers are also tough: they never break down during mixing. They are highly abrasion resistant, UV resistant and will stand up to acid rain and pollution.
PVA can be used in a hybrid mix as well. Architectural precasters and others using glass fiber reinforced concrete can save money and build a stronger and lighter product by replacing some or all of the glass in their mixes. Studies by Professor Shah of Northwestern University and others have shown that a combination of PVA and AR glass yields a better, stronger product than glass alone. What was not shown in these studies is that replacing AR glass with PVA yields a far less expensive final product. For example, a typical GFRC mix contains 5% ARG by weight, but has no strain-hardening capability: once it cracks it can fail quickly. At 1.4% by weight, PVA-ECC develops multi-cracks and strain-hardens, absorbing many times the energy of ARG before failure. Yet the fibers are approximately the same cost! So a mix of PVA and ARG can save you 50% on your fiber cost and deliver a superior product.
Studies continue to show that even with 17% to 19% zirconium infused into the glass fibers, they still degrade over time in the highly alkaline environment. Contrast that with PVA: 20 year studies in the field and accelerated aging tests both show minimal degradation. The fibers are also much tougher and fatigue resistant than glass. Bend a glass fiber a few times and it shatters. Do the same test with a PVA fiber and it will take hundreds of bending cycles.
Try some PVA fibers for yourself. Give us a call at (212) 986-2230, extension 120, or pvafibers@kuraray-am.com. |
|
GFRC Replacement |
|
