This specification covers lightweight aggregates intended for use in concrete not exposed to the weather, in which the prime consideration is the thermal insulating property of the resulting concrete. Two general types of lightweight aggregate are group I aggregates, which are prepared by expanding products, such as perlite or vermiculite, and group II aggregates which are prepared by expanding, calcining, or sintering products such as blast-furnace slag, clay, diatomite, fly ash, shale, or slate; and aggregates prepared by processing natural materials, such as pumice, scoria, or tuff. The thermal insulating properties of concrete made from the lightweight aggregate under test shall conform to the maximum average thermal conductivity indicated in the specification. To ensure reasonable uniformity in the gradation of successive shipments of lightweight aggregates, fineness modulus determination shall be made periodically. The aggregate shall be composed predominantly of lightweight cellular and granular inorganic material. The test methods for insulating concrete properties include specimen preparation, then concrete density determination, and determinacy of thermal conductivity. When lightweight aggregates covered by this specification are delivered in packages, the name of the manufacturer, type of aggregate, and minimum mass and approximate volume of the contents shall be plainly indicated thereon.

1.1 This specification covers lightweight aggregates intended for use in concrete not exposed to the weather, in which the prime consideration is the thermal insulating property of the resulting concrete.

1.2 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

1.3 With regard to sieve size and the size of aggregate as determined by the use of testing sieves, the values in inch-pound units are shown for the convenience of the user; however, the standard sieve designation shown in parentheses is the standard value as stated in Specification E 11.

1.3.1 With regard to other units of measure, the values stated in inch-pound units are to be regarded as standard.

The following precautionary caveat pertains only to the test method portion, Section 6, of the specification: 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.