Colonne in C.A. rinforzate con FRP con diverso livello di confinamento

R.C. columns strengthened by PBO-FRCM under axial force and bending moment

Fabric-Reinforced Cementitious Matrix (FRCM) systems, also known as Textile Reinforced Concrete (TRC) are nowadays widely used as confining material to enhance both strength and deformation capacity of columns of seismic resistant r.c. frames. In the past, when carbon fiber was used in the textile, experimental results showed that the efficiency of the wrapping is limited by the connection between substrate and fiber, which is not as effective as when epoxy resins are used. To improve the strength of the connection between fibres and mortar binder in FRCM system, the use of p-Phenylene BenzobisOxazole (PBO), having a molecular structure capable of establishing chemical bonds with hydrated c…

Prove sperimentali in situ su tipica muratura messinese rinforzata con CAM: arco in muratura a piena scala

Il presente lavoro illustra i risultati di una campagna sperimentale di prove in situ recentemente realizzata nella zona di Messina, in particolare il fine della sperimentazione è la valutazione del comportamento a taglio-compressione della tradizionale muratura messinese (nota in generale per le basse proprietà meccaniche dovute alle caratteristiche della pietra, alla cattiva qualità della malta ed alla mancanza di connessioni trasversali) rinforzata con il sistema CAM (Cucitura Attiva dei Manufatti).

Response behaviour of reinforced concrete beams strengthened in shear with FRP

In this paper an analytical model, able to predict the shear-displacement response of slender RC beams reinforced in shear with FRP, is presented. It allows to evaluate the complete strain and stress fields, for each load step, on the basis of the MCFT framework. The key role of the effective strain of FRP reinforcement at failure has been investigated. At the same time, the interaction FRP-steel stirrups has been taken into account by introducing an appropriate factor. It is able to reproduce the decrease of stirrups stress level when an external reinforcement is used. The proposed model has been validate against a database of specimens collected in literature. Results have shown the remar…

Experimental Tests on Typical Masonry of Messina Area (Italy) Retrofitted with CAM: Full Scale Panels

The present paper focuses on an in-situ testing campaign recently developed in the Messina area, Italy, aiming at the assessment of the in-plane shear behaviour of traditional masonry retrofitted with the innovative CAM system (a system of 3D pre-tensioned stainless steel ties). The typical masonry of Messina area, is characterised by low mechanical properties, both for its texture and for the bad quality of mortar, as well as lack of transverse connections. The high seismic risk characterizing the zone, amplifies the need for in-plane strengthening and transverse connections improving. The CAM system, Masonry Active Ties or Manufact Active Confining, allows to realise a 3D pre-tensioned ty…