Experimental pull-out tests and design indications for strength anchors installed in masonry walls

Abstract

This study deals with the identification of the mechanical behavior of chemical anchors embedded in masonry walls. 108 pull-out tests are carried out in five types of masonry walls built with clay brick or vertically perforated units with cement mortar. Different parameters are taken into account: embedment depths, masonry type, anchor position (injection either in brick units or in mortar joints). The axial load capacity and the failure mode are observed for each test. The results are examined by means of elastic and plastic models assessing the efficiency of anchors installed in headers, stretchers or mortar joints. The anchors injected in mortar joints are shown to have much greater pull-out capacity than that found for anchors in bricks. Passing from 90 to 160 mm of embedment depth, a minimum increase by 40% of pull-out strength is observed. The most common failure modes are the sliding failure, which occurs for short anchors or weak masonry, and mixed sliding/cone failure, for long anchors or strong masonry. An analytical model is proposed to design anchors in order to avoid or at least to limit brittle masonry failures and to identify the field of application of uniform stress models.

Experimental estimation of energy dissipation in rocking masonry walls restrained by an innovative seismic dissipator (LICORD)

“…6). Details about the mechanical features of the walls and their components can be found in (Giresini et al 2020).…”

Investigation and Improvement of Bond Performance of Synthetic Macro-Fibres in Concrete

“…The above observations suggest that the mechanical interlock component [ 47 ] plays a predominant role in the pull-out resistance of synthetic fibres. There existed a distinct difference between the pull-out behaviour of metallic fibres and anchors [ 48 , 49 , 50 ], the underlying reason being the difference in material stiffness. The higher stiffness of the latter could mobilise the shear cone resistance of concrete and possibly lead to cone failure of concrete eventually.…”

Torsion-shear behaviour at the interfaces of rigid interlocking blocks in masonry assemblages: experimental investigation and analytical approaches

“…One of the key factors influencing the behaviour of the conventional mortared block masonry is the bond strength between the mortar and the units, which also affects the pull-out strength of injected anchors frequently used in masonry walls [30]. Similarly, the shear strength between the locks and the main body of an interlocking block is of utmost importance for dry masonry structures made of units with corrugated interfaces.…”