ASTM E997-11

Glass specimens to be tested shall be mounted in a standard test frame with four sides supported, or in a test frame designed to represent specific glazing conditions.

A standard test frame shall be used when it is desired to evaluate the probability of breakage of glass specimens with edge support conditions held constant.

A test frame designed to represent a specific glazing condition shall be used when it is desired to evaluate the probability of breakage of glass specimens in the specified glazing system.

Loads on glass in windows, curtain walls, and doors may vary greatly in magnitude, direction, and duration. Any load (wind, snow, etc.) that can be transformed into a 60-s duration equivalent uniform design load can be considered. Load transformation techniques are addressed in the literature (1, 2, 3).

The strength of glass varies with many different factors including surface condition, load duration, geometry, relative humidity, and temperature (4). A thorough understanding of those strength variations is required to interpret results of this test method.

1.1 This test method is a procedure to determine if the probability of breakage of glass specimens tested is significantly greater than, significantly less than, or not significantly different than the specified probability of breakage when exposed to a specified design load. It is not intended to be a design standard for determining the load resistance of glass. Practice E1300 shall be used for this purpose.

1.2 This test method describes apparatus and procedures to select and apply a proof load to glass specimens, to determine the number of glass specimens to be tested, and to evaluate statistically the probability of breakage. This test method may be conducted using the standard test frame specified herein or a test frame of the user's design.

1.3 Proper use of this test method requires a knowledge of the principles of pressure measurement and an understanding of recommended glazing practices.

1.4 The values stated in inch-pound units are to be regarded as standard.

1.5 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 7.