M. CORRADI(*1), A. BORRI(*) and A. VIGNOLI(**)
(1) Corresponding Author. Voice: +39 075 585 3906 Fax: +39 075 585 3897
(*) Department of Civil and Environmental Engineering, School of Engineering,
University of Perugia Via Duranti, 93 – 06125 Perugia, Italy
(**) Department of Civil and Environmental Engineering, School of Engineering,
University of Florence, Via di S. Marta, 3 – 50139 Florence, Italy
This paper reports the results of a series of tests carried out on masonry panels in order to find the experimental values for masonry shear strength and stiffness. Twenty-five panels were assembled in the laboratory or cut from walls in-situ for a total number of sixty-three tests. The panels had been strengthened with either conventional and innovative materials and techniques. The strengthening techniques were applied as method of repair for damaged panels or as a method of preventive reinforcement. Concerning conventional methods, injections with new lime-based mixes, ferrocement and deep repointing of mortar joints panels injected, were used to strengthen unreinforced masonry. Other tests were made by gluing to the wallettes sheets of unidirectional fibre glass (GFRP) with an epoxy resin or GFRP grids with an hydraulic mortar. Another reinforcement technique involved retrofitting similar undamaged and damaged masonry panels with polypropylene nets. The purpose of the tests was to analyze the effectiveness of the intervention, above all as a technique of seismic-upgrading work. The results of the experiments carried out, in terms of lateral resistance and stiffness increases, although varying according to the retrofitting method applied, have highlighted their limitations as well as their advantages.