Acrylic Co-Polymer For Use In GFRC - Forton VF-774
Forton® VF-774 is an all acrylic, co-polymer dispersion (51% solids) specifically formulated for theGFRC production process. VF-774 is UV stable. It is further formulated to be stable and durable in the high pH Portland cement-based GFRCcomposite. Forton® VF-774is the world-wide standard concrete additive for making lightweight GFRC, Glass Fiber Reinforced Concrete, panels.It is recognized by the PCI as the only polymer supported with a 20 yeardurability study.
Durability of the GFRCcomposite, especially the maintenance of the long-term flexural strain to failure property, i.e. ductility of the composite is based on a 20 year independent test program. PCI Compliance with Appendix G of MNL 130, the Manualfor Quality Control for Glass Fiber Reinforced Concrete Products from the PCIfor the elimination of the seven day wet cure.
VF-774 Benefits Include
• Elimination of the seven day wetcure required to achieve the maximum strengths of the GFRC composite.
• Significant improvements in the long-termdurability of the GFRC composite, especially the maintenance of thelong-term flexural strain to failure property, i.e. ductility of the composite.
• Improvedworkability of the mix at low water/cement ratios, further enhancingthe strength of the cured cement matrix.
• Easy spraying of vertical surfaces without having the face mix sag.
• Complete dispersion of iron oxide pigments for batch-to-batch color consistency of face mixes.
• UVstability of the Forton® polymer means architectural finishes maintain their “as produced” colors.
• Hardcured face mixes for better sand blasting uniformity.
• Tighter,denser cured product, which reduces absolute moisture absorption and vapor permeability while at the same time significantly reducing the rate of absorption as a function of time.
• Elimination of crazing and spider cracking in the face mix due to the soft polymerparticles in between the cement particle and the sand grain.
PCI Compliance: Forton® VF-774 complies with Appendix G of MNL 130, the Manualfor Quality Control for Glass Fiber Reinforced Concrete Products from the PCIfor the elimination of the seven day wet cure.
Product may freeze in transit – order may be delayed due to freezing temperatures.
HANDLING& STORAGE - Forton® VF-774 is supplied in 5-gallon pails (40 lbs/18 kgs), 55-gallon drums (480 lbs/218 kgs)and totes (2,300 lbs/1,043 kgs). VF-774 should not be allowed tofreeze. Recommended storage temperature range: 50°F - 100°F (10°C -38°C). VF-774 should be stored in closed containers out of direct sun light and away from direct sources of heat.
SHELFLIFE - Shelf life of VF-774 is one year in unopened containers whenproperly stored. Smooth-On cannot guarantee shelf life of opened or repackagedunits. Important: This product has limited shelf life. Use as soon as possible after opening.
PRE-MIXING - VF-774can separate over time in storage or transit as evidenced by caramel liquid on the surface. Gently stir with a paddle for 30 seconds. Pre-mixing one time per24 hour usage cycle is recommended.
MEASURING& MIXING - Assemble all components and accessories before you begin.
§ PortlandCement, Type I (White or Gray)
§ SilicaSand (washed, graded, dried. 0 Retention on 20 mesh sieve)
§ Plasticizer(see recommendation based in Technical Bulletin)
§ AR GlassFiber (see recommendation based in Technical Bulletin).Important: Do not use “E” Glass
§ Pigments- UV Stable, Iron Oxide (liquid or dry, if required)
§ WeighingScales- with digital gram accuracy (do not use postal scale, dietary scale,etc.)
§ Mechanical/ Power Mixer: 5 - 10 hp vertical high shear mixer or CS Unitec handheld MG120,MG140 or MG160 blades
§ NIOSHApproved Dust Mask to minimize dust inhalation while using components
Important:Components should be mixed in proper sequence. Standard concrete mixers may beused, but it is recommended to use a high shear mixer specially designed forGFRC to ensure a thoroughly mixed, lump free slurry is produced.
Step1: Weigh or batch all materials.
Step2: Add all liquids, including VF-774 and 2 oz. of plasticizer, to mixer.
Step3: Start mixer on slow (300-500 rpm).
Step 4: Addpigment if used.
Step5: Add sand.
Step 6: Add cement and increase mixer speed to high (1,000-1,800 rpm).
Step 7: Mixfor 1 - 2 minutes.
Step 8: Addthe remaining plasticizer to achieve desired workability.
Step 9: Reduce mixer speed to slow (300-500 rpm) and gradually add fiber (Premix only) until dispersed (typically not more than one minute). Important: Mixing too long or at too high a speed after fiber has been added can filamentize or damage the fiber, resulting in placement issues and reduced strengths.
APPLYING A RELEASE AGENT - Common mold materials include mold rubber,melamine coated board and birch faced plywood or FRP with tooling resin gelcoat. Use a high quality release agent meant for releasing architecturalconcrete such as Crete-Lease 20 VOC to release GFRC castings from the mold.
Casting - Pour mixture in a single spot at the lowest point of mold, and let mixture seek itslevel. Vibrating: After casting, consolidate the slurry and remove entrappe dair using a vibrating table or hand vibrator.
Spraying- For higher volume of smaller parts or making large cladding panels, GFRC slurry can be sprayed into molds using rotor/statoror peristaltic pumps specifically designed for GFRC. Regardless of spray pumpused, a face coat without fiber is typically applied first. After the face coathas properly stiffened, a fiber backup mix is applied in multiple passes, with proper compaction following each pass. For low volume application - A hoppergun (Kraft EZY Deck Pro is recommended) can be used to apply face mix. GFRC back up mix can be applied by hand.
Curing - After placement, cover GFRC with plastic tarp / sheeting to prevent excessive moisture loss and maintain heat of hydration to ensure a proper initial cure.Let cure in the mold for 12-16 hours. Curing temperatures should be maintained above 50°F/10°C in order to ensure proper film forming of the VF-774.