Shear test method analysis of earth block masonry mortar joints

Abstract

A series of triplet shear strength tests and numerical simulations were conducted in this study to secure a suitable shear test method for earth block masonry mortar joints. The effects of the block type, horizontal mortar joint, loading location, mortar material, specimen form, block dimensions, and elasticity modulus on the shear performance on the masonry joints were analyzed. The optimal test method was determined based on comprehensive evaluation via Analytic Hierarchy Process (AHP). The shear test method significantly affects the shear performance along the mortar joint of earth block masonry; the shear strength of specimens with horizontal mortar joints is generally higher than that without a horizontal mortar joint. The loading location affects the shear strength of the 6-block specimen, and the shear strength of the specimen loaded at the half-block is higher than that of specimen loaded at the whole block in most cases. The distribution of the shear stress along the height of the mortar joint varies unevenly by specimen form. The stress distribution at the mortar joint tends toward uniformity as the block’s elasticity modulus increases. The 4-block specimen showed favorable test operability and stress state in addition to the highest comprehensive AHP value, 0.322. The 4-block triplet shear strength test is recommended as the standard assessment for earth block masonry.