Pull-Out Behavior of Adhesive Connections in URM Walls

Earthquake Spectra, 32(4)

REFERENCE

Dizhur D., Schultz A.E., Ingham J. (2016). Pull-out behavior of adhesive connections in URM walls. In Earthquake Spectra 32(4). DOI: 10.1193/011115EQS006M

Scope and methodology

• 400 adhesive anchor tested in eleven existing URM buildings in Christchurch, Whanganui and Auckland

• Investigate anchor pull-out capacity when subjected to pseudo-static loads.

• Compare the performance of anchors installed at an angle of minimum 22.5 degrees and anchors positioned horizontally.

• Variables studied: adhesive type, strength of the substrate, embedment depth, anchor diameter, overburden level, anchor rod type, quality of installation and use of metal foil sleeve.

FINDINGS

• The ideal breakout of masonry in a roughly conical masonry failure surface was not observed.

• Cementitious grout is a suitable anchor adhesive and a detailed installation procedure needs to be developed.

• Adhesive anchors oriented horizontally were found to have a higher pull-out capacity and stiffness compared to the bent (22.5 degrees) anchor equivalent;

• Increasing the increasing embedment depth, the pull-out-capacity increases and the average bond stress at failure decreases.

• Quality assurance in the installation process is critical to achieving an adequate pull-out capacity