[2.5.1.1
Glass Fiber Reinforced Concrete (GFRC) Units
Provide glass fiber reinforced concrete (GFRC) units at locations indicated
on the drawings. Comply with PCI MNL-128 recommended practice for glass
fiber reinforced concrete, including Appendix G, Polymer Modified Glass
Fiber Reinforced Concrete Panels.
a.
Design precast benches to sustain a live load of not less than 10
kPa 200 pounds per square foot.
b.
Provide ASTM C 150 cement, use only one brand and type of cement
throughout project.
c.
Provide alkali resistant (AR) glass fibers produced specifically
for use in glass fiber reinforced concrete, minimum three percent
glass fiber content.
d.
Provide clear silica sand aggregate passing 1.18 mm No. 16 seive;
washed, dried and free from deleterious materials. Provide type
with successful history of uses in GFRC fabrication standard with
the manufacturer.
e.
Provide 20/25 MPa 3000 psi concrete, 28 day minimum compressive
strength with approximately 1921 kg/cubic meter 120 pcf density;
shell thickness of 10 to 16 mm 3/8 to 5/8 inch.
f.
Provide manufacturer's standard acrylic thermoplastic copolymer
admixture.
g.
Provide factory finished units standard with the manufacturer;
texture and color as selected.
(1)
Provide white or grey cement consistent with final finish.
(2) Provide ASTM C 33 (less gradation) facing aggregates, clean,
hard, durable, inert and free of staining and deleterious
materials; as required to match approved samples.
(3) Provide color meeting ASTM C 979, pure, non-fading mineral
oxides, maximum ten percent cement weight; as required to match
approved samples without impairing strength of GFRC.
(4) Apply finish meeting ASTM D 4060 waterborne crosslinked
acrylic 49.5 +/- two percent solids by weight providing 1000
cycles per 0.0254 mm 1000 cycles per 0.001 inch resistance to
abrasion.
h.
Prefabricate units within following maximum fabrication tolerances.
(1) Dimension:
Plus or minus 3 mm 1/8 inch in any direction,
noncumulative.
(2)
Material Thickness:
Plus 6 mm 1/4 inch and minus 0-inch.
(3) Total Unit Thickness:
Plus 6 mm 1/4 inch and minus 3 mm 1/8
inch.
(4)
Insert Locations:
Plus or minus 6 mm 1/4 inch.
SECTION 02870
Page 18
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