Search results for "Steel bar"
showing 8 items of 8 documents
Integrazione di celle fotovoltaiche ibride nel vetromattone
2012
L’invenzione riguarda l’integrazione del vetromattone con celle solari ibride (organiche/inorganiche), conosciute come Dye-sensitized Solar Cell (DSC). La combinazione del vetromattone con le DSC consente di migliorare le prestazioni del prodotto originario rendendolo in grado di produrre energia pulita. Le caratteristiche di trasparenza e isolamento termo-acustico del prodotto possono essere regolate agendo sulla configurazione delle DSC. Il prodotto può essere assemblato a formare pannelli fotovoltaici per la realizzazione di facciate traslucide energeticamente “attive” in varie condizioni luminose (condizioni di luce diffusa o artificiale) e indipendentemente dall’angolo di radiazione so…
Influence of design mistakes and material degradation on the collapse of a long-span RC roof in South Italy
2020
Abstract In 2004, during ordinary maintenance work, consisting in the waterproofing of a building located in the South of Italy, the long-span (14.50 m) in situ cast reinforced concrete (RC) roof partially collapsed. The building, constructed in 1950, was in service as a cinema up to 1967 and utilized as a school up to 1985. Finally, it was a hotel up to 2000. In 2004, when the building was not in service and underwent maintenance work, it partially collapsed under the dead load. After the collapse, which involved a large portion of the roof, several beams and two columns, the Court nominated a first Official Technical Consultant in order to investigate on the causes of failure and related …
Flexural Response of RC Beams Failing in Shear
2020
In this paper, an analytical model to determine the flexural response of simply supported RC beams under four-point bending tests failing in flexure and shear is presented. The model is able to provide load-deflection curves, including also the shear contributions, which are determined assuming a kinematic rigid plastic model able to consider different strength contributions such as the concrete, the dowel action, and transverse reinforcement with progressive yielding. For each contribution, a physical explanation is provided to link the strength evaluation with a specific kinematic evolution for the determination of the overall response of RC beams under combined shear and flexural loads. …
Compressive behavior of FRP externally wrapped R.C. column with buckling effects of longitudinal bars
2018
Abstract In this paper, a calculation model to simulate the compressive behavior of R.C. columns with square cross-sections externally wrapped with FRP, including buckling effects of the longitudinal bars and reduction of the confinement pressure induced by the buckled compressed bars, is presented and discussed. The model distinguishes the cases of corner and side bars, calculating the different critical lengths and the critical loads. The Teng et al. (2009) model was adopted to predict the compressive behavior of FRP-confined concrete, and the Dhakal and Maekawa (2002) model was taken into account to predict the compressive behavior of longitudinal bars. The critical length and critical s…
Pannello precompresso di vetromattoni assemblati a secco per la realizzazione di involucri traslucidi
2012
L’invenzione riguarda la realizzazione di un pannello di vetromattoni montati “a secco” -da impiegare per la realizzazione di involucri edilizi traslucidi anche nel caso di edifici alti- che è in grado di rispondere adeguatamente alle sollecitazioni orizzontali (quali quelle dovute a vento e sisma) grazie all’applicazione della tecnica della precompressione mondirezionale. Per offrire una risposta ai limiti imposti dalla tecnica di assemblaggio tradizionale dei vetromattoni (“ad umido”), l’applicazione della precompressione consente, infatti, di dare ai pannelli preassemblati “a secco” una rigidezza adeguata anche in direzione normale al loro piano di posa, sfruttando le buone caratteristic…
Analytical prediction of the shear connection capacity in composite steel–concrete trussed beams
2016
Steel–concrete trussed composite beams are a particular types of composite girders constituted by a steel truss embedded in a concrete core. The truss is typically composed by a steel plate or a precast concrete slab working as bottom chord while coupled rebars are generally used to form the upper chord. Moreover, a system of ribbed or smooth steel rebars welded to the plate and forming the diagonals of the truss, works as web reinforcement. In the present study, the attention is focused on the evaluation of the shear resistance of the connection between bottom steel plate (the bottom chord) and concrete core through the diagonal bars of the truss developing a mechanical model able to accou…
A Quasi-likelihood Markov model for the hardenability of steel
1992
To evaluate the hardenability of steel the Jominy test can be used. A steel bar of fixed dimensions is heated up to about 850 °C and then quenched from one end by water spray. Its hardness y is then measured at increasing distances d from this quenched end giving observations (d, y(d)), which form the Jominy curve. For each Jominy curve these observations can be fitted by descending curve μ = μ(d; η) with shape parameters η = (η 1,..., η p ) T which are assumed to vary along the alloying elements (C, Mn, Cr etc.).
Degraded Gerber Saddles in RC Bridges
2023
Sudden failure of reinforced concrete (RC) or prestressed concrete (PC) Gerber saddles of bridges and viaducts has occurred all around in the word in the last few years due to corrosion of steel bars. The danger of sudden and brittle failure is often due to general and pitting corrosion of steel bars, concrete crushing, and loss of bond in steel bars. In this paper, the flexural response of reinforced concrete Gerber supports under their self-weight with or without service loads was investigated through determination of the load-deflection response of beams, with the focus on the consequences of pitting corrosion and loss of bond in steel bars. A simplified strut-and-tie model was developed…