Dry Masonry Strenghtening through Basalt Fibre Ropes: Experimental Results against Out-of-Plane Actions

Abstract

One of the most important characteristics that historical masonry should have is that of a monolithic behavior. Without these basic feature, no structural analysis could be considered reliable. If this characteristic is absent, strengthening bearing masonry giving it a transversal monolithic behavior is one of the first retrofitting actions to do so as to improve its seismic performance. Hence come out the idea to develop a new consolidation technique specially formulated for historical masonry. Stitching masonry through continuous flexible elements is an innovative technique, able to connect the several masonry components and to attribute to it a monolithic behavior according to the principles that govern the intervention on existing buildings: minimal intervention, compatibility, reversibility, respect of authenticity, matter conservation, control of the visual impact and possibility of recognizing the intervention. Basalt fibers ropes of 4 mm of nominal diameter (declared by manufacturer), have been used in this experimental program as continuous flexible element. The technique has been already tested and proved to be effective for improving the behavior against “in-plane” actions. Good results has been obtained also excluding synthetic adhesives (resins), with an enhancement about reversibility. In this paper, the results of an experimental campaign aimed to evaluate the technique effectiveness against “out-of-plane” loads are presented. Reinforced and unreinforced brick masonry specimens have been tested simulating vertical bending mechanism activation to evaluate the stitches contribute.