Glass Fiber Reinforced Concrete
Glass Fiber Reinforced Concrete
Specifications
PART 1 – GENERAL
1.1
Related Documents
A.
1.2
Drawings and general provisions of the Contract applicable to GRC works.
Summary
A.
Work under this section includes design, fabrication, storage, handling & installation of
Glass fiber reinforced concrete (GFRC) panels as indicated on Contract
drawings. B. Anchors and connection hardware for GRC panel installation.
1.
1.3
Definitions
A.
1.4
Design Reference Sample: Sample of approved smooth finish GFRC preapproved
by the Architect.
Performance Requirements
A.
1.5
GFRC panels as per the design provided by the Engineer
Structural Performance: Provide GFRC panels, anchors and connections, capable of
withstanding the design loads, as well as the effects of thermal- and moisture-induced
volume changes, according to load factors and combinations established in PCI
MNL
128, “Recommended Practice for Glass Fiber Reinforced Concrete Panel.”
Submittals
A.
B.
Product Data: Include GFRC design mixes.
Shop Drawings: Show fabrication and installation details
for GFRC
panels,
including the following and to be reviewed by the Architect prior to the
commencement of fabrication:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Structural analysis data by the qualified professional engineer.
Panel elevations, sections and dimensions.
Thickness of GFRC facing &backing mix.
Finishes.
Joint and connection details.
Erection details.
Locations and details of connection hardware attached to
main structure.
Erection sequence for special conditions (if applicable).
Relationship to adjacent materials.
Descriptions of loose, cast-in, and field hardware.
C. Samples: Representative of smooth finished GFRC sample (200 x 200
mm) D. Welding certificates (if applicable).
E. Source Quality-Control Program: For GFRC manufacturer.
F. Source Quality-Control Test Reports: For GFRC, inserts, and anchors.
Glass Fiber Reinforced Concrete
1.6
Quality Assurance
A. Design Responsibility: Design GRC units by registered professional engineer employed
or retained by panel Manufacturer, in accordance with the procedures in Prestressed
Concrete Institute (PCI).
B.
Manufacturer & Erector Qualification: A manufacturer with a demonstrated
capability to produce GRC products with quality and scope defined for this project.
C. PCI Manuals: Comply with requirements and recommendations in the following PCI
manuals:
1.
2.
D.
Mock-up: After samples are accepted by the Engineer, produce full scale unit
meeting requirements as follows:
1.
2.
1.7
PCI MNL 128, “Recommended Practice for Glass Fiber Reinforced Concrete
Panels.”
PCI MNL 130, “Manual for Quality Control for Plants and Production of Glass Fiber
Reinforced Concrete Products.”
Retain mock-up on site as standard of quality for GRC panel works,
when accepted by the Engineer.
Incorporate mock-up into work in location acceptable to the Engineer .
Delivery, Storage, and Handling
A.
Handle and transport GFRC panel to avoid damage.
1.
2.
3.
B.
Place non-staining resilient spacers between panels.
Support panels during shipment on nonstaining material.
Protect panels from dirt and damage during handling and transport.
Store GFRC panels to protect from contact with soil, staining, and physical damage.
1. Store GFRC panels with nonstaining resilient supports in same positions
as when transported.
2. Store panels on firm, level, and smooth surfaces.
3. Place stored panels so identification marks are clearly visible.
PART 2 – PRODUCTS
2.1
Mold Materials
A.
Molds: Rigid, dimensionally stable, nonabsorptive material, warp and buckle free, that
will provide continuous and true GFRC surfaces; nonreactive with GFRC and
capable of producing required finish surfaces.
1.
Mold-Release Agent: Commercially produced liquid-release agent that will not
bond with, stain or adversely affect GFRC surfaces and will not impair subsequent
surface or joint treatments of GFRC.
Glass Fiber Reinforced Concrete
2.2
GFRC Materials
A. Ordinary Portland Cement: Confirms to ASTM C150/ BS EN 197 Use same type, brand,
and source throughout GFRC production.
B.
Glass Fibers: Alkali resistant, with a minimum zirconia content of 16 percent, 1 to 2
inches (25 to 50 mm) long, specifically produced for use in GFRC, and complying with
PCI MNL 130.
C.
Sand: Washed and dried silica, complying with composition requirements of ASTM
C144; passing No. 16 (1.2 mm) sieve.
D.
Water: Potable; free from deleterious material that may affect setting, or strength of
GFRC and complying with chemical limits of PCI MNL 130.
E.
Polymer Curing Admixture: Acrylic thermoplastic copolymer dispersion complying with
PCI MNL 130.
F.
Chemical Admixtures: ASTM C494/C494M, containing not more than 0.1 percent
chloride ions.
G. Coloring Admixture: ASTM C979, Synthetic mineral-oxide pigments or colored water
reducing admixtures, temperature stable, non-fading and alkali resistant.
2.3
Anchors, Connectors, and Miscellaneous Materials
A.
Carbon steel shapes and plates : Material confirms to ASTM A 36/A 36M
Finish: Zinc coated by hot-dip galvanize process according to ASTM A123/A123M or
EN ISO 1461:1999
B.
2.4
Bolts & Other connectors:
Zinc plated.
GFRC Mixtures
A.
Backing Mix: Proportion backing of mixed portland cement, glass fibers, sand and the
admixtures to comply with design requirements. Provide nominal glass-fiber content of
not less than 5 percent by weight of total mix.
B.
Face Mix: Proportion face mix of portland cement, sand, facing aggregates, and
admixtures to comply with design requirements.
C.
Mist Coat Mix: Portland cement, sand slurry, and admixtures, of compatible mix
proportions as backing mix without glass fibers.
D.
Polymer Curing Admixture: 6 to 7 percent by weight of polymer curing admixture to
cement.
2.5
Mold
Fabrication
A.
Construct molds that will result in finished GFRC complying with profiles, dimensions,
and tolerances indicated, without damaging GFRC during stripping. Construct molds
to prevent water leakage and loss of cement paste.
1.
B.
Coat contact surfaces of molds with form-release agent.
Provide solid backing and supports to maintain stability of liners during GFRC
application. Coat form liner with form-release agent.
Glass Fiber Reinforced Concrete
2.6
GFRC Fabrication
A.
Proportioning and Mixing: For backing mix, meter sand/cement slurry and glass fibers
to spray head at rates to achieve design mix proportions and glass-fiber content
according to PCI MNL 130 procedures.
B.
Spray Application: Comply with general procedures as follows:
1.
2.
3.
4.
C.
Hand form and consolidate intricate details, incorporate formers or infill materials, and
over spray before material reaches initial set to ensure complete bonding.
D.
Inserts and Embedment: Build up homogeneous GFRC bosses or bonding pads over
inserts and embedments to provide sufficient anchorage and embedment to comply
with design requirements.
E.
Curing: Employ curing method that will ensure sufficient strength for removing units
from mold. An acrylic thermoplastic copolymer dispersion may be used to assist dry
curing of GFRC units.
1.
F.
2.7
Spray mist coat over molds to a nominal thickness of 3mm on planar surfaces.
Proceed with spraying backing mix before mist coat has set, using procedures
that produce a uniform thickness and even distribution of glass fibers and
matrix.
Consolidate backing mix by rolling or other technique to achieve complete
encapsulation of glass fibers and compaction.
Measure thickness with a pin gage or other acceptable method at least once
for each sq. m of panel surface. Take not less than three measurements per
panel.
After initial curing, remove panel from mold and place in a shaded area
without directly exposing to sunlight.
Panel Identification: Mark each GFRC panel to correspond with identification mark
on Shop Drawings. Mark each panel with its casting date.
Fabrication Tolerances
A. Dimensional Tolerances: Manufacture GFRC panels so each finished unit complies with
the following dimensional tolerances. For dimensional tolerances not listed below,
comply with PCI MNL 130.
1.
Overall Height and Width of Units, Measured at the Face Adjacent to Mold
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
10 feet (3 m) or less, plus or minus 3 mm.
More than 10 feet (3 m), plus or minus 3 mm per 3 m; 6 mm maximum.
Edge Return Thickness: Plus 13 mm, minus 0 mm.
Architectural Facing Thickness: Plus 3 mm, minus 0 mm.
Backing Thickness: Plus 6 mm, minus 0 mm.
Panel Depth from Face of Skin to Back of Panel Frame or Integral Rib: Plus
10 mm, minus 6 mm.
Variation from Square or Designated Skew (Difference in Length of Two
Diagonal Measurements): Plus or minus 3 mm per 1800 mm or plus 6 mm
total, whichever is greater.
Local Smoothness: 6 mm per 3 m.
Bowing: Not to exceed L/240 unless unit meets erection tolerances
using connection adjustments.
Maximum Permissible Warpage of One Corner out of the Plane of the
Glass Fiber Reinforced Concrete
Other Three:1.5 mm per 300 mm of distance from nearest adjacent corner.
2.8
Finishe
s
A. Finish exposed surfaces of GFRC as follows to match approved sample and mock-up.
Panel faces shall be free of joint marks, grain, or other obvious defects.
a)
2.9
Smooth-Surface Finish: Provide free of sand streaks, honeycombs,
and excessive air voids GFRC surface to receive paint.
Source Quality Control
A.
Quality-Control Testing: Establish and maintain a quality-control program
for manufacturing GFRC panels according to PCI MNL 130.
a)
Test materials and inspect production techniques.
b)
Quality-control program shall monitor glass fiber content, spray rate,
unit weight, product
c) Physical properties and shear strength, and curing period and conditions.
d) Prepare test specimens and test according to PCI MNL 128 & 130 procedures.
e) Produce test boards at a rate not less than one per work shift per
spray
machine and for each mix design.
f)
For each test board, determine glass fiber content according to BS 1170,
and flexural yield and ultimate strength according to BS 1170/ ASTM C947.
B. GRC properties shall be as per the PCI MNL 128/130 and as per below table.
Properties
Units
2
Compressive Strength
N/mm or Mpa
Flexural strength
N/mm or Mpa
2
Coefficient of Thermal Expansion
Young’s Modulus
C. Fire Properties:
2
N/mm or Mpa
Wet Bulk Density
Class A/1 - ASTM E84
Flame Spread Index: 0
Smoke Developed Index: 15
NFPA 285: Passed
Class A1 : BS EN 13501-1:2007+A1:2009
> 40
LOP: > 8
MOR: > 18
8x10-6 – 12x10-6
-
Dry Bulk Density
value
3
Kg/m
3
Kg/m
>17000
>1800
>2000
Glass Fiber Reinforced Concrete
PART 3 – EXECUTION
3.1
Examination
A.
3.2
Examine structure and conditions for compliance with requirements for
installation tolerances, true and level bearing surfaces, and other conditions affecting
performance.
Erection
A. Install steel brackets and other accessories required for connecting GFRC panels to
supporting members and backup materials.
3.3
B.
Lift GFRC panels at designated lifting locations provided by the manufacturer and
install without damage.
C.
Install GFRC panels level, plumb,
square, and
in alignment.
Provide
temporary support and bracing as required to maintain position, stability, and
alignment of panels until permanent connections are completed. Maintain
horizontal and vertical joint alignment and uniform joint width. Remove projecting
hoisting devices.
D.
Connect GFRC panels in position by bolting or other methods specified in
approved shop drawings. Remove temporary shims, wedges, and spacers as soon as
possible after connecting is completed.
Erection Tolerances
A.
Erect GFRC panels to comply with the following noncumulative tolerances:
1.
Plan Location from Building Grid Datum: Plus or minus 13 mm.
2.
Top Elevation from Nominal Top Elevation: As follows:
a. Exposed Individual Panel: Plus or minus 6 mm.
b. Nonexposed Individual Panel: Plus or minus 13 mm. c.
Exposed Panel relative to Adjacent Panel: 6 mm.
d. Nonexposed Panel relative to Adjacent Panel: 13 mm.
3.
Support Elevation from Nominal Elevation: As follows:
a. Maximum Low: 13 mm. b.
Maximum High: 6 mm.
4.
Maximum Plumb Variation over the Lesser of Height of Structure or 100
Feet (30 m): 25 mm.
5.
Plumb in Any 10 Feet (3 m) of Element Height: 6 mm.
6.
Maximum Jog in Alignment of Matching Edges: 6 mm.
7.
Maximum Jog in Alignment of Matching Faces: 6 mm.
8.
Face Width of Joint: As follows (governs over joint taper):
a. Panel Dimension 6 m or Less: Plus or minus 6 mm.
Glass Fiber Reinforced Concrete
b. Panel Dimension More Than 6 m: Plus or minus 8 mm.
9.
Maximum Joint Taper: 3/8 inch (10 mm).
10.
Joint Taper in 3 m: 6 mm.
11. Differential bowing, as erected, between adjacent members of same design: 6
mm.
3.4
Repairs
1.
2.
3.
3.5
Repairs will be permitted provided structural adequacy of GFRC panel and
appearance are not impaired, as approved by Architect.
Mix patching materials and repair GFRC so cured that patches blend with
adjacent exposed surfaces.
Remove and replace damaged GFRC panels when repairs do not comply with
requirements.
Cleaning and Protection
A.
Perform cleaning procedures, if necessary, according to GFRC manufacturer’s written
instructions. Clean soiled GFRC surfaces with detergent and water, using soft fiber
brushes and sponges, and rinse with clean water. Prevent damage to GRC surfaces
and staining of adjacent materials.