Mechanical behavior of brick masonry panels under uniaxial compression

Abstract

Structural design in masonry requires clear understanding of the behavior of the composite unit-mortar material under various loading conditions. The mechanical characteristics of brick masonry are influenced by the individual properties of the bricks and the mortar. The results of an experimental study focused on the properties of brick masonry using different combinations of bricks and mortars are presented in this paper. The strength and the elastic modulus of brick masonry under uniform concentric vertical loads have been investigated for strong mortar (M:1:3 cement-sand) and weak mortar (M:1:6 cement-sand) arrangements. The failure mechanisms of the infill walls with horizontal coring bricks have also been examined.

A generalised damage model for masonry under compression

“…However, when mortar is placed as a binder between the units, its behaviour is affected by the bond and the unit-mortar interface characteristics. Some researchers have observed a non-linear progressive stiffening response of mortar under compression until a threshold strain in their experiments (Miccoli et al, 2014;Ozhan and Cagatay, 2014). Dry surface-interfaces of the dry-stack masonry show more pronounced nonlinear progressive stiffening until a larger threshold strain in comparison to conventional mortarinterface (Andreev et al, 2012;Jaafar et al, 2006).…”

“…Commonly, mortar used to join the masonry units together has lesser strength and stiffness than the units themselves. A non-linear progressive stiffening behaviour in the beginning of compression loading regime for weak cement mortars, earthen mortars and dry surface-interface is a significant observation (Andreev et al, 2012;Jaafar et al, 2006;Miccoli et al, 2014;Ozhan and Cagatay, 2014). In this study, the unit-mortar interface and the dry surface-interface are assumed to exhibit nonlinear progressive stiffening as shown in Figure 1(b).…”

“…The parameter R o defines the initiation of cracking and hence it defines the initial size of the damage threshold surface f ¼ 0. The micro-cracks were assumed to commence at 30% of compressive strength of masonry composite (Ozhan and Cagatay, 2014). The form of this parameter was derived in the form of 30% of compressive strength f c at which damage was assumed to start occurring in the form of micro-cracks.…”