ASTM F2248-19 - Standard Practice for Specifying an Equivalent 3-Second Duration Design Loading for Blast Resistant Glazing Fabricated with Laminated Glass

1.1 This practice sets forth a method to specify an equivalent 3-second design loading suitable to use with Practice E1300 to select the thickness and type of blast resistant glazing fabricated with laminated glass to glaze a fenestration. Glass plies used to construct laminated glass are recommended to be either annealed or heat strengthened glass. This analytical method for glazing should be used with caution for glazing panels larger than 1.8 m by 2.4 m (6 ft by 8 ft) as this size panel exceeds database of testing upon which this standard is based.

1.2 This practice applies to blast resistant glazing fabricated using laminated glass only, including single laminated glass and insulating glass fabricated with laminated glass. As a minimum, insulating glass shall use laminated glass for the inboard (protected side) lite.

1.3 This practice assumes that blast resistant glazing shall be attached to its supporting frame using a captured bite so that it does not detach in the event of fracture due to a blast event.

1.4 Blast resistant glazing designed using this practice recommends the use of annealed or heat strengthened glass plies for the laminated glass. Blast testing has shown that use of fully tempered glass plies, when fractured during a blast event, have poorer post blast performance than annealed or heat strengthened glass plies. Laminated glass fabricated with fully tempered glass plies has a tendency to leave the supporting glazing system frame after fracture whereas laminated glass fabricated with annealed or heat strengthened glass plies will remain in the frame and absorb remaining load through tensile membrane behavior. Use of the annealed or heat strengthened glass plies will also reduce the amount of load transferred into the structure.

1.5 The equivalent 3-second design load as determined herein shall not apply to the design of monolithic glazing, plastic glazing, or security film applied to existing glazing configurations in an attempt to achieve blast resistance.

1.6 The values stated in SI units are to be regarded as the standard. Values given in parentheses are for information only. For conversion of quantities in various systems of measurements to SI units refer to ANSI IEEE/SI 10.

1.7 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.

1.8 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.