Search results for "Concrete."
showing 10 items of 249 documents
Seismic behaviour of hybrid steel trussed concrete beams
2010
Friction-based beam-to-column connection for low-damage RC frames with hybrid trussed beams
2022
Hybrid Steel-Trussed Concrete Beam (HSTCB) is structural typology suitable for light industrialization. HSTCBs usually cover long span with small depths, which lead to significant amount of longitudinal rebars. The latter make beam-column joints more prone to damage due to earthquake-induced cyclic actions. This phenomenon can be avoided using friction-based BCCs. Friction devices at Beam-to-Column Connections (BCCs) have become promising solutions to reduce the damage experienced by structural members during severe earthquakes. Few solutions have been developed for cast-in-place Reinforced Concrete (RC) and steel-concrete composite Moment Resisting Frames (MRFs), because of the difficulty …
Experimental investigation on high-strength fibre-reinforced concrete beams subjected to bending and shear
2008
The results of an experimental campaign carried out on a number of high-strength concrete beams loaded in 4-point bending are presented in this paper, where the roles of the both steel hooked fibres and the transverse reinforcement are investigated, for different values of the shear span. All tests were displacement-controlled. The results – mostly in terms of load-deflection curves – confirm what is well known in the literature, that an adequate amount of steel fibres can turn a brittle shear-type failure into a ductile flexural-type failure, to the advantage of the ultimate bearing capacity in flexure and shear, that can be fully exploited without increasing the transverse reinforcement. …
Comparative analysis of shear resisting models for hybrid steel trussed concrete beams
2018
The hybrid steel trussed concrete beams represent a structural solution widely adopted in the industrial constructions thanks to the numerous advantages due to their use, such as economic convenience, high performances and constructional speed de-riving from the partial prefabrication process and from the self load-carrying capacity of the beam in the first operative phase, prior to the in-site casting of concrete. The hybrid steel trussed concrete beams examined in the present study are constituted by two prin-cipal components, i.e. a steel joist with inclined rebars, realized in industry, which is welded to a smooth steel plate and then embed-ded within the concrete material cast in situ.…
Experimental investigation on mansory panels manufactured with pumice lightweight concrete
2010
The possibility of using pumice aggregates for concrete in structural applications is discussed. In particular, the mix design of lightweight concrete for the manufacturing masonry units having proper strength, is discussed. Moreover, the design of the unit shape according to the technical code requirements and making it possible to arrange reinforcing steel bars is described. Reinforced bearing masonry walls, made with the concrete units in question, were manufactured and tests on the panels and on the designed units were carried out. For comparison, tests on concrete units and structural elements were carried out after the substitution of pumice aggregates with ordinary lightweight aggreg…
Thermal and structural properties of a hemp–lime biocomposite
2013
Abstract The need to reduce greenhouse gases emission produced by the building sector leads to the research of renewable and less impacting materials that can replace traditional ones. This subject has encouraged new researches on biocomposite concretes with the aim to exploit renewable resources like vegetal fibres intended as materials whose production processes are generally characterized by low costs and energy demand. This biocomposite is obviously much lighter than concrete and, therefore, can be suitably used in such cases where a structure cannot be overloaded, for instance in the realization of a green covering on top of a preexistent building. In this work, a first analysis of the…
Frammenti di mosaico riportati su calcestruzzo:le interazioni con il supporto e il progetto di conservazione
2010
Scritti in onore di Pellegrino Capaldo
2014
La qualità dei servizi è stata riconosciuta come un rilevante aspetto caratterizzante la performance dell’azienda pubblica, analogamente alla capacità di operare secondo criteri di efficienza e nel rispetto dei vincoli di bilancio. Sebbene sia possibile riscontrare alcuni significativi casi di adozione di politiche di customer satisfaction nelle amministrazioni pubbliche italiane, a tutt’oggi il tema presenta significative criticità, specialmente in ordine agli aspetti metodologici e agli strumenti operativi che consentano di integrare dette politiche nel sistema di programmazione e controllo delle aziende che erogano tali servizi. Il presente lavoro adotta una diversa prospettiva di analis…
Numerical Calibration of a Simplified Model for FRP Confinement of Columns
2018
This paper presents the calibration of a simplified analytical model for concrete columns confined by fiber reinforced polymer (FRP) jackets. The model allows evaluating the increase of strength, ductility and dissipated energy without defining the lateral confinement pressure and it can be easily extended for the assessment of FRP confinement in design applications. This model was obtained by a simplified procedure based on the best fit of experimental data available in the literature and the coefficient of determination (R2) was evaluated in order to estimate the accuracy of the regression analysis. A numerical database resulting from finite element (FE) analyses was compiled and reported…
Simplified analytical models for compressed concrete columns confined by FRP and FRCM system
2017
In order to consider the response of concrete columns confined by FRP and FRCM system, proper models have to be formulated. In this context the present paper shows a generalized criterion for the determination of the increase in strength, in ductility and in dissipated energy for varying corner radius ratio of the cross section and fiber volumetric ratio. The procedure is based on the best fitting of several experimental data and unlike the usual empirical approaches available in the literature, the proposed technique relates the confinement effectiveness to a single parameter representative of the relative stiffness between the original concrete core and the reinforcement system. Furthermo…