shear strength

  • Uncategorized

    • Structural behaviour of masonry spandrels of URM buildings subjected to horizontal loading: experimental analysis

    Bruno Calderoni, Emilia Angela Cordasco, Pietro Lenza

    The mechanical behaviour of spandrels has a very significant influence on the seismic capacity of URM multi-storey buildings, which are very common in the historical Italian towns. In this paper the seismic behaviour of masonry spandrels is investigated, in case of a horizontal tensile-resistant element exists at floor level. At this aim experimental tests have been performed on reduced scale (1:10) models of spandrels, made of both tuff masonry and homogeneous material. The specimens have been built using different arrangements of masonry, corresponding to different construction techniques adopted during the time (from XVII up to XX century). The experimental equipment has been purposely designed in order to appropriately reproduce the structural behaviour of spandrels when masonry wall is subjected to horizontal forces acting in their own plane. The observed failure mechanisms and the corresponding M-c curves are reported for all the adopted slenderness ratio and masonry arrangements. Furthermore, in order to evaluate the cyclical performance of this kind of masonry panels, the results of cyclic tests have been analyzed in detail in terms of maximum strength, stiffness at reloading and energy dissipation.

    For this paper is available an extended abstract after the text in Italian

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    • Fibrous reinforced concrete beams in seismic area: experiment and design

    Giuseppe Campione, Calogero Cucchiara

    In the present paper the experimental results referred to monotonic and cyclic tests on fibrous reinforced concrete (FRC) beams are presented and discussed. The influence of longitudinal and transverse steel bars, of type and percentages of fibers, of the shear to depth span ratios and of the cover thickness are estimated. Experimental results highlight that fibers are a very effective shear reinforcement in R.C. beams both under monotonic and cyclic actions, but under reversal cyclic actions, if shear failure is attained, the contribution due to the fibers reflects mainly in the bridging actions across the cracks and brittle failure can be partially avoided. In these cases and especially for seismic design ductile failure in flexure is more suitable and over strength in shear is required, the latter being obtained with a good combination of fibers and stirrups. Form theoretical point of view shear and flexural strength prevision was made by using a recent model developed by the authors able to take into account of the main parameters governing the flexural behavior of fibrous reinforced concrete beams. Finally, some design consideration for the use of FRC in seismic design of beams are given.

    For this paper is available an extended abstract after the text in Italian

  • Uncategorized

    • Experimental definition of shear deformation and strength for masonry panels

    Anna Brignola, Maurizio Ferrini, Sergio Lagomarsino, Francesco Mangone, Stefano Podesta'

    The paper shows the results obtained during experimental campaign of diagonal compression tests in Tuscany, in which a significant number of masonry panels were tested. The aims of this research are mainly two. On the one hand the authors compare medium values of shear strength and shear stiffness varying the knowledge level proposed in the OPCM 3431 code (LC1, LC2 and LC3). On the other hand, the authors verify shear strength and stiffness range value, given by OPCM 3431 code for masonry typology most recurring in Tuscany (Italy).

    Available in Italian only

  • Uncategorized

    • Shear performance of clay tile masonry walls: comparison between experimental and numerical response

    Valeria Badalamenti, Liborio Cavaleri, Salvatore Priolo

    In the present paper the results of an experimental study for the mechanic characterization of clay tile masonry walls under shear forces are discussed. Further in the paper the reliability of the models for the prediction of the mechanic characteristics under shear forces proposed by some codes is verified. Diagonal tests have been carried out; then the relationship of the Italian and European codes, correlating the mechanical properties of the components and the normal compression mechanical property of masonry to its shear mechanical properties (strength and elastic modulus), have been verified. This control has requested also normal compression tests on masonry walls made of the same blocks used for diagonal tests, on the blocks themselves and on the used mortar.

    Available in Italian only.