EFFECT OF MORTAR TYPE AND JOINT THICKNESS ON THE COMPRESSIVE STRENGTH OF BRICK MASONRY PRISMS: A FINITE ELEMENT APPROACH

Abstract

Brick masonry is among the highly versatile and popular construction techniques adopted in India and which have been used in numerous projects over the last decades. There are majority buildings across the nation that have been erected using brick masonry cement mortar technique, while the lime mortar method is predominantly employed in heritage and historical buildings. The strength of masonry construction is greatly influenced by the strength of bricks, mortar, and more importantly, the bond between the brick and mortar. There are cases where masonry fails because of weakness at the interface between brick and mortar. There are numerous factors that govern the structural strength and stability of masonry walls, such as the characteristics of the mortar itself, the properties of bricks, construction skills, and the thickness of mortar joints. Among all of these, the thickness of the mortar is one major factor that affects the load carrying capacity and strength. Experimental studies on brick masonry prisms with different mortar thicknesses are available in the literature; however, analytical investigations using detailed finite element modeling are limited. Hence, the present study aims to evaluate the behavior of brick masonry prisms with varying mortar thicknesses through finite element analysis. The current investigation involves the use of micro modeling concepts in bricks, mortar joints, and interfaces are considered independently. behavior of the brick and mortar material is simulated through DP model, whereas the interface between bricks and mortar is described by intact Cohesive Behavior. The masonry prisms with mortar joint sizes of 13 mm, 20 mm, and 27 mm are analyzed for the condition of axial compression loading when either cement or lime mortar is utilized. This includes analyzing the response of masonry prisms with respect to load-displacement relationship, peak load, compressive strength, stress distribution, and failure modes. The results indicated that the 20 mm mortar thickness prism exhibited the highest compressive strength for both cement and lime mortar. This suggests that 20 mm mortar thickness provides optimum bond performance and can be effectively used in modern masonry construction as well as heritage masonry structures.