Mark J. Masia¹, Goran Simundic², and Adrian W. Page²
1) Associate Professor, Centre for Infrastructure Performance and Reliability, School of Engineering,
The University of Newcastle
University Drive, Callaghan, NSW 2308, Australia
e-mail: Mark.Masia@newcastle.edu.au
2) Structural Testing Manager and Emeritus Professor (respectively), Centre for Infrastructure Performance
and Reliability, School of Engineering, The University of Newcastle
University Drive, Callaghan, NSW 2308, Australia
e-mail: {Goran.Simundic,Adrian.Page}@newcastle.edu.au

Keywords: Flexural strength, Lattice masonry, Hit and miss brickwork, Masonry screens,
Out-of-plane loading.

Abstract. In lattice masonry (also known as hit and miss brickwork) the mortar perpend joints are left unfilled and the masonry units are spaced along the courses to leave a gap between adjacent units, allowing the passage of light and air through the wall. Regardless of whether this masonry is used in a loadbearing or nonloadbearing application, it must still be capable of spanning between supports to resist out-of-plane lateral loading to satisfy robustness requirements and to resist wind and/or earthquake actions and hence requires structural design. The Australian Standard AS3700: Masonry Structures [1] provisions for one way vertical bending can be applied in the case of lattice masonry by using a section modulus based on the net bedded area. However, the provisions for horizontal bending and two way bending require that the masonry be constructed with all perpends completely filled and therefore lattice masonry falls outside the scope of AS3700 for horizontal and two way bending.
The paper describes a study to assess the behaviour of unreinforced lattice masonry walls subjected to lateral out-of-plane pressure loading and supported in either one way horizontal or two way bending configurations. Twelve single leaf lattice masonry walls, 1194 mm high x 1190 mm long, were constructed using extruded clay bricks (230 mm long x 110 mm wide x 76 mm high) and 1:1:6 (cement : lime : sand) mortar. Three walls were tested in two way bending and nine walls, with varying overlap between units in adjacent courses, were tested in one way horizontal bending. The load versus deformation behaviour and the observed failure modes are reported. The AS3700 provisions for solid masonry were used to predict the panel strengths and an assessment of the suitability of the provisions for the design of lattice masonry is made.