Experimental Investigation and Interface Material Model for the Cohesive-Frictional Shear Response of Soft-Brick Masonry under Applied Compression

摘要

Experimental investigation on the cohesive-frictional shear behavior of soft-brick masonry under various levels of applied compression is reported. The progressive failure in the bed joint produced by a crack propagating along the brick-mortar interface is evaluated for masonry made with a soft brick and mortars of different strengths. The load response indicates a cohesive-frictional-type interface response with a cohesive interface bond and residual frictional resistance. The fracture planes after failure depend on the type of mortar used and the applied compression. Failure surfaces are rougher in cement-rich mortars, and the roughness increases with the level of confinement. A cohesive-frictional interface model is developed and calibrated using experimental responses. The cohesive-frictional parameters obtained from the experiments vary with the type of mortar and the level of compression. The peak cohesive shear stress and cohesive fracture energy increase with the level of compression applied normal to the shear plane. The interface with the cement-rich mortars exhibit a more pressure-sensitive response. A higher cohesive peak stress is obtained for cement-rich mortar. Cement-rich mortar exhibits a more brittle response with smaller displacements at the initiation of crack and at complete separation.