Experimental and numerical investigation of brick masonry behavior considering mortar joint thickness using an RVE approach

In this study, the authors explore how the thickness of mortar joints has a significant impact on compressive behavior of the masonry of bricks in an integrated numerical modeling and experimental system. The joint thickness of masonry prism nine-course and joint thickness of 5mm, 10mm and 20mm were subjected to uniaxial compression tests. The results show that making the joint thicker i.e. 5mm to 20mm, compressive strength reduces by 34 % and the initial value of 3.5 MPa to 2.3 MPa, and initial elastic modulus decreases by 23 %. The middle area of the 9-course sample was verified as a Representative Volume Element (RVE), which was a successful way of eliminating border influences. Also, a micro modeling model of ABAQUS using the Concrete Damage Plasticity (CDP) model resulted in a high level of accuracy and the differences between experimental values of strength were limited to a range of 4.3 to 8.5%. These findings provide quantitative evidence supporting design code recommendations (e.g., ASTM C1314) to limit mortar bed joint thickness to 10 mm or less, thereby preserving the structural integrity and stiffness of masonry walls.