4.1 Deformation and strength properties are measured only on the masonry between flatjacks. Boundary effects of the collar joint behind the wythe tested and adjacent masonry are neglected. In the case of multi-wythe masonry, deformability is estimated only in the wythe in which the flatjack is inserted. Deformability of other wythes may be different.

1.1 This test method describes an in situ method for determining the deformation properties of existing unreinforced solid-unit masonry. (See Note 1.) This test method concerns the measurement of in-situ masonry deformability properties in existing masonry by use of thin, bladder-like flatjack devices that are installed in cut mortar joints in the masonry wall. This test method provides a relatively non-destructive means of determining masonry properties.

Note 1: Solid-unit masonry is that built with stone, concrete, or clay units whose net area is equal to or greater than 75 % of the gross area.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3 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.