Title: Experimental Efficiency of FRP Bars as Injected Anchors for Masonry Structures

Author(s): Francesca Ceroni, Alberto Balsamo, Marco Di Ludovico

Publication: Symposium Paper

Volume: 360

Issue:

Appears on pages(s): 383-394

Keywords: masonry, out-of-plane mechanisms, injected anchors, FRP bars, bond behavior.

DOI: 10.14359/51740637

Date: 3/1/2024

Abstract:
Masonry structures are very sensitive to out-of-plane mechanisms under horizontal actions. A common traditional technique to avoid or mitigate the activation of these mechanisms is represented by injected anchors made of steel bars aimed to improve the connections between orthogonal masonry walls or between floors and masonry walls. The bars are usually embedded in the masonry by means of cement-based grout in holes realized inside the elements to be connected. Recently, an increased interest has developed in the scientific community about the use of Fibre Reinforced Plastic (FRP) bars as alternative to the steel ones for injected anchors, mainly because of their high tensile strength and inertia to corrosion, which can give them high durability, in addition to the use of high-performance grouts. The paper reports the results of experimental pull-out tests realized by the Authors on several types of FRP bars used as injected anchors in small masonry specimens made of yellow tuff blocks. A hydraulic lime and pozzolana-based grout is used to fix the bars in holes realized in the masonry specimens along an embedded length of 250 mm. The set-up is realized in order to apply pure tension to the bars and shear stresses along the bar-grout and the grout-masonry interfaces. The results are analysed in terms of maximum pull-out forces, failure modes and force-displacement relations in order to evidence the global performance of each tested system, especially in relation with the diameter and the surface treatment of the bars. Some comparisons with literature formulation for predicting the pull-out force are developed too.