Evaluating the axial compression behaviour of hollow concrete block masonry walls with small-size openings: Various opening positions and their influence on experimental results

Abstract

Openings such as windows or channels for ventilation and heating systems are commonly encountered in masonry buildings to meet with functional needs. Although these openings are known to reduce the strength and stiffness of masonry walls, however, the relationship between the position of openings and load bearing capacity of masonry walls is not well understood. Therefore, the primary aim of this study is to investigate the effect of double opening positions on the axial compressive behaviour of masonry walls constructed with hollow concrete block units. Seven one-half scale walls with different double opening positions were constructed using hollow concrete block units and subjected to a uniformly distributed axial load. The compressive performance such as the strength, stiffness, load-deformation behaviour, stress-strain response, cracking pattern and failure behaviour of the walls have been reported. The results indicate that the 50% reduction in sectional area ratio caused by introducing two small openings in the walls reduced the load bearing capacity by 36 to 50%. Measured ultimate strain values ranges between 5.5 to 38.8% reduction in walls with openings compared with the wall without opening. Vertical cracking, face spalling, and block rupture were the dominant failure modes for walls with double openings, in contrast to mainly vertical cracks observed in the solid wall. This research provides valuable insights into how the positions of double openings influence the performance and overall structural response of hollow concrete block masonry walls under compression load.