Reliable information on shear resistance is needed when performing retrofits and seismic upgrades of masonry buildings. While shear strength of a masonry wall is difficult to measure without resorting to large-scale testing, less destructive in-place tests of single masonry units provide a comparative figure that can be correlated to full-scale wall behavior. This less destructive alternative is more economical than large-scale testing and is desirable when a building’s historic integrity must be maintained.

A recently published ASTM standard – ASTM C 1531-02, Standard Test Methods for In Situ Measurement of Masonry Mortar Joint Shear Strength Index – includes three alternative test methods and a concise technical description of the equipment, procedures, and calculations required for the tests. The in-place shear test, also known as the push test, provides a direct measurement of the shear resistance of mortar joints in masonry.