Yuri Z. Totoev1, Adrian W. Page2, Goran Simundic3

  1. Lecturer Department of Civil, Surveying, and Environmental Engineering The University of Newcastle, Callaghan, NSW 2308, AustraliaE-mail: ceyuri@civeng.newcastle.edu.au
  2. CBPI Professor in Structural Clay Brickwork and Dean Faculty of Engineering The University of Newcastle, Callaghan, NSW 2308, Australia E-mail: apage@mail.newcastle.edu.au
  3. Laboratory Manager

ABSTRACT

Masonry structures contain slip joints between concrete slabs and their supporting masonry walls to accommodate differential movements due to concrete slab shrinkage, thermal effects and masonry moisture expansion. Traditionally slip joints in Australia consist of one or two layers of a membrane type material placed between masonry and concrete. According to Australian Standards all structures must be designed for earthquake loading. Therefore the slip joints must satisfy two apparently conflicting requirements – to slip under long-term loads for adequate serviceability performance and to transmit short-term dynamic loads from earthquake in order to create effective load paths through the structure. Recent work at the Universities of Newcastle and Adelaide has indicated that these types of joint do exhibit substantial shear capacity under short-term load. There is an urgent need to establish their behaviour under long duration induced strains (i.e. differential movement effects) to clarify their potential to behave as slip joints for the serviceability limit state. Long-term tests are currently underway at the University of Newcastle to investigate this behaviour. In these tests the frictional forces generated in the joint between a shrinking concrete slab and a preloaded masonry wall have been monitored over a three month period for a selected range of joints. This paper presents preliminary results of this experimental project.

Key words: load-bearing masonry, slip joints, concrete slab shrinkage

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