The Durability of Composite Wood-Steel Systems

Nell’ambito della valutazione e del controllo della qualità tecnologica in edilizia, la conoscenza del comportamento nel tempo dei prodotti e componenti complessi per l’edilizia, risulta aspetto fondamentale, in particolare per quei prodotti tecnologicamente “innovativi” per i quali la normativa non prevede ancora prove specifiche per valutarne la durabilità. In particolare, oggi risulta sempre più diffuso l’impiego di sistemi assemblati o con connessioni tra materiali di diversa natura, tra cui i sistemi legno-acciaio, ottenuti rinforzando le travi in legno lamellare con piastre in acciaio forate, incollati mediante una resina epossidica bicomponente. Tali sistemi, che sono stati già ogget…

Strengthening of masonry walls subjected to out-of-plane loads using CFRPs

This paper presents an experimental investigation carried out on masonry panels subjected to axial load and bending moment in the plane of minor inertia. The masonry type consist of calcarenite ashlars and mortar joints; the reinforcement is made of Carbon Fibres Reinforced Polymer (CFRP) strips applied with the wet-lay-up system. Tests are carried out with controlled displacements. Results have been recorded at each step in terms of: horizontal force and corresponding displacements; moment and curvature at the base of the wall; strains on the CFRP strips near the base of reinforced specimens in order to observe the delamination phenomen. Comparison between the results relative to unreinfor…

Numerical modeling of masonry structures reinforced by FRP plate/sheets

Indagine sperimentale sull'impiego di materiali compositi per il rinforzo di volte in muratura

Experimental investigation on masonry elements subjected to eccentric axial loads

The flexural behaviour of masonry rectangular cross-sections is studied in order to characterize the mechanical behaviour of structural elements under axial eccentric loads by means of a proper law. First the experimental response of walls under vertical centred loads is observed and a stress–strain law depending on two parameters is given in order to fit the experimental results. Subsequently the behaviour of walls nominally equal to the walls mentioned before is investigated under eccentric vertical loads, and the response is observed in terms of moment–curvature relation. To this point a comparison is made between the moment–curvature response obtained experimentally and the moment–curva…

Flexural behavior of external beam-column reinforced concrete assemblages externally strengthened with steel cages

In this paper, an experimental study referring to the flexural behavior of full-scale external beam-column joints externally strengthened with steel angles and strips and subjected to cyclic reversal loading is presented. One control specimen and five other specimens having the same characteristics as the control specimen but strengthened with steel angles and strips along beams and columns, and characterized by different configurations of strengthening in the critical regions, were tested. The control specimen was designed with a weak column and strong beam to reproduce the most common cases of old frame structures in the Mediterranean area, which were designed only for gravity loads and a…

“Indagine sperimentale per la caratterizzazione meccanica di elementi strutturali misti in legno-acciaio e legno-acciaio-calcestruzzo"

The paper reports the results of the research activity aimed to define the physical-mechanics characteristics of structural elements made of wood-steel, and/or wood-steel-concrete, jointed by steel con¬nectors. The elements used for the tests are: glulam beams with two dif¬ferent dimensions (110x240x4000 mms and 110x140x4000 mms); steel flats 100x6x4000 mms with holes  20 mms arranged like "quinconce"; steel connectors like: flat with 6 mms thickness;  18; angular; polymeric synthetic binder with epoxy base bicomponent (Xepox 40.3/5). Shear tests have been made to define the capacity for deformation and the re¬sistance of the different steel connectors. Moreover, bending tests have been m…

Debonding Phenomena in CFRP Strengthened Calcarenite Masonry Walls and Vaults

In this paper the results of an experimental investigation on full-scale reinforced masonry elements like vaults and walls are presented. The masonry type is constituted by calcarenite ashlars and bed joint mortar and the reinforcement is constituted by Carbon Fibre Reinforced Polymer (CFRP) strips. Preliminary experimental results obtained in a previous research by the authors on the local behaviour at the interface CFRP-calcarenite are summarized. Tests with controlled displacement are carried out on out-of-plane loaded walls and cylindrical vaults loaded at a quarter of the span. Results of tests carried out before and after the application of the reinforcement made it possible to evalu…

Risposta sismica di pannelli in muratura armata con blocchi di inerti leggeri

Risposta sismica di pannelli in muratura armata con blocchi di inerti leggeri

Experimental and analytical response of masonry elements under eccentric vertical loads

The flexural behaviour of masonry rectangular cross-sections is studied in order to characterize the mechanical behaviour of structural elements under axial eccentric loads by means of a proper law. First the experimental response of walls under vertical centred loads is observed and a stress-strain law depending on two parameters is given in order to fit the experimental results. Subsequently the behaviour of walls nominally equal to the walls mentioned before is investigated under eccentric vertical loads, and the response is observed in terms of moment-curvature relation. To this point a comparison is made between the moment-curvature response obtained experimentally and the moment-curva…

CFRP flexural strenghtening of masonry walls: experimental and analytical approach