Estimation of in-situ Masonry Mortar Compressive Strength Using Pendulum Hamming Test Method

Abstract The compressive strength of in-situ masonry mortar was evaluated using the Pendulum Test Method (PHTM). A portable PHTM apparatus specifically designed for this purpose is utilized to indirectly evaluate the compressive strength by inserting steel nails into the horizontal mortar joints of the masonry and measuring the penetration depth. This apparatus can directly test extracted mortar samples without excessive preparation. The discrete attributes of the test outcomes are analyzed to ascertain the repeatability and reliability of the PHTM results. A relationship between penetration depth and compressive strength is established. In comparison with other existing testing methods, it has been confirmed that PHTM is an alternative compression testing method for masonry mortar, with the advantages of high accuracy, minimal preparation work, and good repeatability. The mortar compressive strength estimated by PHTM is reasonably consistent with the mortar cubic compressive strength test results.