Effectiveness of design formulations for injected anchors in masonry elements

The paper is aimed to carry out a critical analysis of the available experimental results of pull-out tests related to several types of injected anchors in masonry elements. The database is also comprehensive of the results of some experimental pull-out tests directly carried out by the Authors. Both data on traditional steel bars and on anchors made by innovative materials embedded in several types of masonry made of natural stones and clay bricks are included in the database. Firstly, the main parameters influencing the experimental pull-out forces in the collected database were analyzed. Successively, the experimental values of the pull-out forces were compared with theoretical predictions provided by existing formulations and their reliability was discussed. Finally, regression analyses were carried out on the available database in order to assess new design formulations taking into account the main parameters influencing the performance of injected anchors.