Coperture in vetro stratificato: criteri di progettazione

This paper concerns the design activity about laminated glass structures for the evaluation of criteria to optimize the design. This target is reached by using a preliminary study of the normative frame in national and international field. Forward by studying the bibliography on laminated glass structure. Application is on canopy designed by authors. Here are reported the step design procedures starting by definition of load, the restraints condition for structure element and a 3d model is produced by using a FEM method

Shear-to-Moment Interaction in Glass Beams with Open Cross Sections

An experimental investigation regarding the flexural behavior of glass beams with a length of 1,200 mm and rectangular, T-shaped, or I-shaped cross sections is presented and discussed. T-shaped and I-shaped cross sections were obtained by assembling laminated glass (LG) panels of 200 mm depth and 12.76 mm thickness through an acrylic adhesive. Three specimens for each series investigated were tested in flexure, focusing on the flexural and shear response of beams through the determination of the load-deflection curves and crack patterns at rupture. The shear span to depth ratio a/d was 2.25, which is a very low value, and interaction of shear and bending moment occurred during the tests. An analytical model is presented for a preliminary design of composite glass beams. The model, able to predict the load-deflection response of the beam, includes limit states attributable to flexure, glass web crushing, and glue shear failure. The experimental data generated, confirmed by numerical analyses, show the effectiveness of the analytical model to reproduce experimental results

Influence of concrete cover on the compressive strength of fiber reinforced concrete columns

The paper focuses on the influence of the concrete cover on the strength of confined compressed columns made of fiber reinforced concrete. A mechanical model has been developed based on the ultimate state conditions of concrete core, concrete cover and transverse steel. The cases of plain concrete and fiber reinforced concrete are analysed and focus on the beneficial effects due to the presence of fibers. The model has been verified against data obtained from concentric compressive tests on concrete specimens reinforced with transverse steel and fibers

Influenza del coefficiente di poisson sul comportamento in compressione di colonne composte acciaio-calcestruzzo a sezione circolare

In the paper an analytical model able to predict the whole compressive response of stub CFT subjected to uniaxial compression is presented and discussed. Cases examined re-ferred to member with circular cross-section having length 400 mm and diameter ranging be-tween 88.9 and 457 mm and wall thickness between 6 and 8 mm. Two steel grades of 275 and 460 MPa yielding stress were examined and four concrete grades were investigated (20, 28, 40 and 45 MPa). The proposed model take into account of the variable confined pressures exercised by steel wall on concrete core and of the biaxial state of stresses induced in steel wall. The model was verified both in term of load-shortening curves with data available in the literature and with most recent codes (Eurocode 4, 1995 and Japanese code AIJ ) in term of load carrying capa-city showing good agreement

Some recent results on the compressive and flexural behaviour of composite members

Experiemntal results from compression and flexural tests on steel tubulare columns having circular or rectangular transverse cross-section and infilled with plain or fiber reinforced concrete (FRC) are analysez. for composite members differenti lengths and different dimensions of transverse cross-section were considered in order to assess the influence on behavior in flexure and in compression.The fiber investigated with different percentage were syntetic, carbon and deformed steel fibers. The constituent materials were characterised through compressive and split tests on conconcrete cylinders. Load.shortning and load-delection curves were determined including the sotnening response. Simplified expressions for the calculus of the bearing capacity of composite members are given

Retrofitting of existing steel MR-frames by encasing the columns

The study concerns the behaviour of steel MR-frames subjected to vertical and lateral forces, not properly designed according to capacity design criteria, and upgraded by means of encasing the steel columns with concrete having different grade. The purpose of the paper is to examine if the proposed technique allows one to adequately increase the lateral stiffness and the resistance of the frames. Pushover analyses on multi-storey frames are performed trough a non-linear calculus program, able to take into account of the second order effects. The behaviour of frames with encased columns was compared with those of the bare frames, highlighting that with the proposed technique it is possible to locate the plastic hinges at the ends of the beams, out of the joint. Moreover, it is possible to ensure at the system enough lateral stiffness and strength for the requirements of the limit state damage and to achieve adequate global ductility for a good seismic behaviour