Designation: C 1666/C 1666M – 07

Standard Specification for

Alkali Resistant (AR) Glass Fiber for GFRC and Fiber-
Reinforced Concrete and Cement1
This standard is issued under the fixed designation C 1666/C 1666M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope 2. Referenced Documents

1.1 This specification covers minimum requirements for 2.1 ASTM Standards: 2
alkali resistant (AR) glass fibers intended for use in glass D 578 Specification for Glass Fiber Strands
fiber-reinforced concrete (GFRC) by spray-up, glass fiber- D 1577 Test Methods for Linear Density of Textile Fibers
reinforced concrete premix, fiber-reinforced concrete, and D 2256 Test Method for Tensile Properties of Yarns by the
other cementitious based products. Single-Strand Method
1.2 This specification provides for AR glass fiber types and D 3800 Test Method for Density of High-Modulus Fibers
configurations that can be readily incorporated into concrete D 4963 Test Method for Ignition Loss of Glass Strands and
mixes, typical physical properties, minimum zirconia content, Fabrics
and prescribes testing procedures to establish conformance to 2.2 ISO Standards:3
these requirements. ISO 1887 Textile Glass—Determination of Combustible-
1.3 This specification does not address the types of coatings Matter Content
or lubricants used in the manufacturing process of the fibers. ISO 1888 Textile Glass—Staple Fibres or Filaments—
1.4 In the case of conflict between a more stringent require- Determination of Average Diameter
ment of a product specification and a requirement of this ISO 1889 Reinforcement Yarns—Determination of Linear
specification, the product specification shall prevail. In the case Density
of a conflict between a requirement of the product specification ISO 3341 Textile Glass Yarns—Determination of Breaking
or a requirement of this specification and a more stringent Force and Breaking Elongation
requirement of the purchase order, the purchase order shall 2.3 EN Standards:4
prevail. The purchase order requirements shall not take prece- EN 14649 Precast Concrete Products—Test Method for
dence if they, in any way, violate the requirements of the Strength Retention of Glass Fibre in Cement and Concrete
product specification or this specification; for example, by the 2.4 Japanese Industrial Standards:5
waiving of a test requirement or by making a test requirement JISR 3420 Testing Methods of Textile Glass Products
less stringent.
1.5 The values stated in either SI units or inch-pound units 3. Terminology
are to be regarded separately as standard. Within the text, the 3.1 Definitions of Terms Specific to This Standard:
inch-pound units are shown in brackets. The values stated in 3.2 alkali resistant (AR) glass fiber, n—a glass fiber product
each system may not be exact equivalents; therefore, each that is resistant to the alkaline conditions that exist in matrices
system shall be used independently of the other. Combining such as those based on Portland cement, and that are used for
values from the two systems may result in non-conformance the reinforcement of cement, mortar, and concrete products.
with the standard. The resistance is due mostly to the specific composition of the
1.6 This standard does not purport to address all of the glass.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
priate safety and health practices and determine the applica- contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
bility of regulatory limitations prior to use. Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org.
1 4
This specification is under the jurisdiction of ASTM Committee C27 on Precast Available from European Committee for Standardization (CEN), 36 rue de
Concrete Products and is the direct responsibility of Subcommittee C27.40 on Glass Stassart, B-1050, Brussels, Belgium, http://www.cenorm.be.
5
Fiber Reinforced Concrete Made by the Spray-Up Process. Available from Japanese Standards Organization (JSA), 4-1-24 Akasaka
Current edition approved March 1, 2007. Published March 2007. Minato-Ku, Tokyo, 107-8440, Japan, http://www.jsa.or.ja.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

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 C 1666/C 1666M – 07
3.3 chopped strands, n—strands, as defined in 3.10, 6. Materials and Manufacture
chopped to discrete lengths, usually between 3 and 50 mm 6.1 The materials and manufacturing methods used shall be
[0.125 and 2 in.]. such that the fibers produced conform to the requirements in
3.4 filament, n—a single glass fiber, sometimes referred to this specification.
as monofilament.
3.5 GFRC, n—glass fiber-reinforced concrete, sometimes 7. Chemical Composition
referred to as GRC. 7.1 Alkali resistant glass fiber shall have a minimum of
3.6 matrix, n—the concrete (or mortar) without the glass 16 % by mass of zirconium dioxide.
fiber reinforcement.
3.7 roving, n—a number of parallel, continuous, not twisted, 8. Mechanical Properties
strands wound together to form a cylindrical package. 8.1 The AR glass fiber roving or chopped strands shall be
3.8 scrim or net, n—glass fiber roving or yarn strands laid in deemed to comply with the requirements of this specification if
two directions at 90° and then bonded together to form a the results obtained on test samples comply with the values
non-woven stable structured textile fabric. specified in Table 1.
3.9 size, n—coatings applied to filaments during manufac-
ture that facilitate the processing of glass fibers and bond the 9. Performance Requirements
filaments together. Different sizings can provide different
9.1 The strength of AR glass fiber shall be measured
performance characteristics of the fibers.
according to EN 14649.
3.10 strand, n—several parallel filaments of consistent di-
9.2 Users of AR glass fibers shall require that manufacturers
ameter, bonded together with a size.
of AR glass fiber show independent validation of performance
3.11 tex, n—the weight in grams of one kilometre of strand
in the SIC test.
or roving.
3.12 woven roving, n—glass fiber roving products that are 10. Workmanship, Finish, and Appearance
produced by weaving into a structured textile fabric.
10.1 The roving, chopped strands, or textiles shall be free
3.13 yarn, n—glass fiber strands that are twisted together.
from oil, grease, and other contaminants. A roving package
shall be free from obvious damage and shall not be deformed
4. Classification
4.1 AR glass fibers are available in three forms as follows: 11. Inspection
4.1.1 Type I, Roving—a variety of different roving are 11.1 Unless otherwise specified in the purchase order or
manufactured with different processing characteristics, which contract, the manufacturer is responsible for the performance
makes them suitable for particular applications such as chop- of all inspection and test requirements specified herein. Except
ping and spraying, weaving and scrim manufacture, filament as otherwise specified in the purchased order or contract, the
winding, and chopped strand production. manufacturer may use his own or any other suitable facility for
4.1.2 Type II, Chopped Strands—available in lengths from 3
mm [0.125 in.] to 50 mm [2.0 in.]. Chopped strands are
designed to remain either as integral bundles of filaments TABLE 1 Test Requirements
(usually referred to as integral strands) or to breakdown into Property Specification Value Method of Test
individual filaments (filamentize) during mixing (usually re- Zirconia content 16 % min X-ray fluorescenceA
ferred to as water dispersible strands). (ZrO2)
Density 2.68 6 0.3 g/cm3 ASTM D 3800
4.1.3 Type III, Textiles—Available as woven, knitted, or [167.0 6 19 lb/ft3]
non-woven fabrics. Tensile Strength 1.0–1.7 Gpa ASTM D 2256,
[145 3 103–246 3 103 psi] ISO 3341,
JISR 3420
5. Ordering Information Range of 8–30 µm ASTM D 578,
Filament Diameters [313 10-5-118 3 10-5 in.] ISO 1888,
5.1 It shall be the responsibility of the purchaser to specify JISR 3420
all requirements that are necessary for the product under this Roving tex 610 % of ASTM D 1577,
specification. Such requirements to be considered include, but manufacturer’s nominal ISO 1889,
JISR 3420
are not limited to, the following: Strand length 63 mm [60.118 in.] Caliper—Average
5.1.1 ASTM designation and year of issue. of manufacturer’s nominal of 20 measurements
5.1.2 Quantity in kilograms [pounds or tons] for rovings or End count 620 % of Physical count
manufacturer’s nominal
chopped strands or in square metres [square feet or square Loss on ignition <3 % ASTM D 4963,
yards] for textiles. ISO 1887,
5.1.3 Type or types permissible (see 4.1). JISR 3420
Strength retention Minimum value after 96 6 1 h EN 14649
5.1.4 Manufacturer’s product code, if not included in code, in water at 80 61°C [176 6 2 °F]
tex shall be specified for roving, length shall be specified for $250 MPa [36 250 psi]
for water dispersible strands
chopped strands, and weight/unit area or number of strands/ $350 MPa [50 750 psi]
unit length shall be specified for textiles. for integral strands
5.1.5 Whether certificate of analysis by the manufacturer is A
Any party that is interested in doing this test should contact an AR glass fiber
required. manufacturer before running it so as to avoid possible erroneous results.

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 C 1666/C 1666M – 07
the performance of the inspection and test requirements speci- tured, sampled, tested, and inspected in accordance with this
fied herein unless disapproved by the purchaser. The purchaser specification (including year of issue) and any other require-
shall have the right to perform any of the inspections and tests ments stated in the purchase order or contract, and that it meets
set forth in this specification where such inspections are such requirements.
deemed necessary to ensure that material conforms to pre- 13.2 Test Reports—When specified in the purchase order or
scribed requirements. contract, test reports shall be furnished to the purchaser
containing the results of all tests required by this specification
12. Rejection and Rehearing (including year of issue), and any other requirements desig-
12.1 Rejection: nated in the purchase order or contract.
12.1.1 If any test fails to conform to the requirements of 13.3 A signature or notarization is not required; however,
this specification, it shall be cause for rejection of the material the document shall clearly identify the organization submitting
represented by the test. Material that is found to be defective the document. Notwithstanding the absence of a signature, the
subsequent to its acceptance at the manufacturer’s works may organization submitting the document is responsible for its
be rejected, and manufacturer notified. content.
12.1.2 Rejection of fibers shall be reported to the manufac-
turer promptly and in writing, stating the lot number from the 14. Packaging and Package Marking
bag or the box of the rejected fibers. Samples representing 14.1 The product shall be packaged to provide adequate
fibers rejected by the purchaser shall be preserved until protection during normal handling and transportation. The type
disposition of the claim has been agreed to between the of packaging and gross mass (weight) of containers shall,
supplier and the purchaser. unless otherwise agreed upon, be at the manufacturer’s discre-
12.2 Rehearing—When any test fails to meet the require- tion provided that they are such as to ensure acceptance by
ments of Table 1, a retest shall be allowed. This retest shall be common or other carriers for safe transportation at the lowest
performed on twice the number of randomly selected speci- rate to the delivery point.
mens originally tested. The results of the retest shall meet the 14.2 Each shipping container shall be clearly labeled and
requirements of this specification or the lot shall be rejected. show manufacturer’s name or trademark, product code, lot
number or manufacturing code, and net mass (weight). At the
13. Certification manufacturer’s discretion other information may be given.
13.1 Certificate of Compliance/Analysis—The producer or
supplier shall furnish a certificate of compliance/analysis when 15. Keywords
specified in the purchase order or contract. The certificate of 15.1 AR glass fibers; GFRC; glass fiber-reinforced con-
compliance/analysis shall state that the product was manufac- crete; glass fiber-reinforced concrete premix; SIC test; zirconia

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