This standard specifies requirements for vertical core, hollow building blocks, hereinafter called hollow blocks or blocks, made from clay, shale, fire clay, or mixtures thereof, and fired to incipient fusion.
This standard covers two grades of hollow blocks that are classified as Grade 1 and Grade 2.
The use of results from the testing of blocks extracted from masonry structures for determining conformance or non-conformance to the property requirements (see clause 5) of this standard is beyond the scope of this standard.
This standard does not apply to hollow blocks intended for use as paving blocks.
NOTE: The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) should not be considered as requirements of the standard.