GFRC, "Glass Fiber Reinforced Concrete", is a concrete composite consisting of a Portland cement based mix with various length strands of alkali-resistant glass fiber
intrical to the concrete matrix.
GFRC does not use typical graded rock aggregates or steel-reinforcing bars normally associated with concrete, and unlike concrete which is typically pour cast, GFRC
uses a Type I-II Portland cement utilizing various silica sand sizes ranging from a 90 mesh to typically 30 mesh and its typically sprayed into forms in multiple spray
layered passes to create a uniform wall thickness varying from 3/8” to 3/4" in most typical thin section architectural scenarios and as thick as 1.5” in
When the GFRC matrix hardens, the glass fibers act to greatly enhance the panel flexural, tensile, modules matrix, impact strength and compression, making it ideal for
a wide range exterior and interior architectural cladding or re-cladding applications.
GFRC thin section units are lightweight (2.86 to 8.58 lbs psf. In typical applications), durable, and able to faithfully reproduce the color, texture and feel of a wide variety
of stone, materials.
Because GFRC does not require vibration when wet, panels can be cast in 3-dimensions with elaborate profiles and reveals, deep panel, soffit, and window returns,
and finely detailed and subtle surface textures.
Panels can be designed as wall units, spandrels, mullions, column covers, domes, cornices, three-dimensional sculptural architectural, faux rock, site amenities,
landscape boulders, furniture, counter tops and many more items. GFRC is also used for fascia panels, soffits, sun screens, fireplace surrounds, hearths, stone range
hoods and many interior features
GFRC is known by many in this specific industry as the Play-dough of concrete, because of its wide arena of uses and because it is a structurally rated material that
can be cast into so many different shapes with a multitude of uses.
GFRC has been widely used in Theme Parks, Zoo’s, and Aquariums, Hotels/ Resorts; Casinos, Multi story Buildings/ Sky Scrapers, etc…etc… and more recently since
its passage through the ICC process for Residential and Commercial housing.
One of its main uses is for Building type cladding either new or the re-cladding of buildings where the original stone or terracotta may be decaying / failing.
Because of its unique combination of properties that makes it an ideal solution for facade re-cladding and/or over-claddings, as well as historical restorations and
• Panels have the color, texture and shape versatility to faithfully reproduce almost any existing non-glazed exterior facade; and with certain post cast finishes can be
polished or coated with many other stains/ paints and high gloss glazes.
• GFRC panels are up to 80% lighter than standard precast concrete panels, and can often be installed directly over existing facades without imposing excessive
superimposed loads on the building structure;
• GFRC units are very low maintenance, have extreme longevity, and surpass the durability of precast concrete; and in most case exceeding standard precast by many
years because of its matrix and specific additives, it has been accelerated aging tested up to 300 yrs of freeze thaw cycles; As where typical precast will go up to 75yrs.
• GFRC units can be installed from the outside of a building with minimal interference to the existing building;
• GFRC is typically done a s pre-manufactured product because it’s made in a controlled shop environment and then shipped to a specific job site ready to be installed.
• The square foot cost of GFRC is considerably lower than typical curtain wall, or replacement in kind of most stone and terra cotta facades.
The typical properties if GFRC have a typical base range which has been set by the PCI Precast Concrete Institute which regulates the basic manufacturing process,
including materials, procedure and testing. *This base range is a high and low and is based on different mix variables and do not reflect actual individual tests which will
vary from test to test based on mix design, panel thickness, glass content, polymer content.
One of the unique things about GFRC is it can be adjusted in various ways to achieve certain and uniquely higher properties for certain types of demand.
The “typical” base properties of concentric and premix, mix designs set by the PCI for GFRC with a min. cure of 28 days are as follows: (note these are basic #’s and
can vary from company to company depending on certain variables that are met for a specific job)
Shell Thickness 3/8 to 3/4" +1/8" – 0” (Panels)
Shell Thickness 1” +1/2” – 0” (Terra Cotta Replacement Stones)
Glass Fiber 5 - 6% by weight (Roving - Alkali-Resistant fiber)
Glass Fiber 2.8 - 4% by weight (Premix - Alkali-Resistant fiber)
Compressive Strength 6,000 - 9000 psi (cube sample)
Flexural Yield Strength 900 - 1,500 psi (roving method)
Flexural Yield Strength 700 - 1,200 psi (test average - pre-mix method)
Flexural Ult. Strength 1,200 - 2,500 psi (roving method)
Flexural Ult. Strength 1000 - 1,800 psi (test average - pre-mix method)
Weight 6 – 7 lbs/sq. ft.
Coral Stone- USA follows all PCI Standards set forth in the PCI Manual for Quality Control for Plants and Production of Glass Fiber Reinforced Concrete Products.
We hope this helps in your understanding of our Quality GFRC products and we look forward to helping you on your next project!
If you have further questions please feel free to ask us!
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Spec's and Details