ASTM C1666/C1666M-08(2023)

1.1 This specification covers minimum requirements for alkali resistant (AR) glass fibers intended for use in glass fiber-reinforced concrete (GFRC) by spray-up, glass fiber-reinforced concrete premix, fiber-reinforced concrete, and other cementitious based products.

1.2 This specification provides for AR glass fiber types and configurations that can be readily incorporated into concrete mixes, typical physical properties, minimum zirconia content, and prescribes testing procedures to establish conformance to these requirements.

1.3 This specification does not address the types of coatings or lubricants used in the manufacturing process of the fibers.

1.4 In the case of conflict between a more stringent requirement of a product specification and a requirement of this specification, the product specification shall prevail. In the case of a conflict between a requirement of the product specification or a requirement of this specification and a more stringent requirement of the purchase order, the purchase order shall prevail. The purchase order requirements shall not take precedence if they, in any way, violate the requirements of the product specification or this specification; for example, by the waiving of a test requirement or by making a test requirement less stringent.

1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.