Experimental Study on the Compressive Behaviors of Brick Masonry Strengthened with Modified Oyster Shell Ash Mortar

Masonry bricks were widely used in construction of the walls in most of Chinese historical buildings. The low strength of lime–clay mortar used in existing historical brick masonry walls has usually led to poor performance such as cracking and collapse during earthquakes. As the composition of modified oyster shell ash mortar (MOSA mortar) with higher strength is similar to that of lime–clay mortar, it can be used to partially replace original lime–clay mortar for historical brick masonry buildings in order to improve their seismic performance. Previous research has proven that this strengthening method for brick masonry is effective in improving shear strength. In this paper, we present further experimental research regarding the compressive behaviors of brick masonry strengthened by replacing mortar with a MOSA mortar. The test results showed that the compressive strength of brick masonry specimens strengthened by the proposed method meets the design requirements. The formula for calculating compressive strength for brick masonry strengthened by replacing mortar was obtained by fitting the test results. The calculated values were consistent with the tested ones. In addition, the stress–strain relationship of tested specimens under axial compression was simulated using the parabolic model