1 Research Fellow, The University of Newcastle, Priority Research Centre For Energy, dariusz.alterman@newcastle.edu.au
2 Professor Emeritus, The University of Newcastle, Priority Research Centre For Energy, adrian.page@newcastle.edu.au
3 Undergraduate student, The University of Newcastle, Discipline of Civil Engineering, timothy.gray-thompson@uon.edu.au
ABSTRACT
This paper presents the results of an investigation into the influence of the addition of short steel fibres to mortar on masonry bond and direct shear bond strength. Previous tests of fibre reinforced mortars have indicated that higher mortar tensile and flexural strengths can be achieved. The investigation extends this to the unit-mortar interface. Bond wrench tests to determine masonry bond strength were carried out in accordance with AS3700-2011. Since the Australian standard does not contain a shear strength test, triplet tests in accordance with European Standard EN1052-3 were used to determine the shear strength. Mortar-to-masonry bond is a critical component that affects not only the strength of the masonry construction but also its durability. While traditional mortar uses fine sand only, this investigation examines whether the addition of small steel fibres to the mortar mix increases the masonry shear and bond strength, especially for cored masonry units.
To gain a greater understanding of the effects that the fibres may have on mortar properties, a range of variables were considered, including the extruded clay brick patterns (coring percentage), the proportion of fibres, the mortar water-cement ratio as well as the presence of lime. Image analysis techniques and microscopic examination were also conducted to examine failure surfaces as well as the mortar-brick interface to better understand the bond phenomenon.
KEYWORDS: bond strength, direct shear strength, fibre reinforced mortar, image analysis technique
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