3.1 This test method was developed to measure more accurately the diagonal tensile (shear) strength of masonry than was possible with other available methods. The specimen size was selected as being the smallest that would be reasonably representative of a full-size masonry assemblage and that would permit the use of testing machines such as are used by many laboratories.

Note 1: As a research test method used only for the purpose of evaluating the effects of variables such as type of masonry unit, mortar, workmanship, etc., a smaller size specimen could be used if the available testing equipment will not accommodate a 1.2-m [4-ft] square specimen. However, there is a lack of experimental data that would permit an evaluation of the effect of specimen size on the shear strength or to permit a correlation between the results of small-scale specimen tests and larger specimens.

1.1 This test method covers determination of the diagonal tensile or shear strength of masonry assemblages by loading them in compression along one diagonal (see Fig. 1), thus causing a diagonal tension failure with the specimen splitting apart parallel to the direction of load.

1.2 Annex A1 provides requirements regarding the determination of the diagonal-tension strength of masonry under combined diagonal-tension and compressive loading.

1.3 These test methods cover the application of the tests using either inch-pound or SI units. The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.4 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems, 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.