Search results for " reinforced concrete"
showing 10 items of 42 documents
Nonlinear Response of RC Structures: Statistical Effects of Artificial Ground Motions
2020
The selection of seismic inputs for nonlinear dynamic analysis is widely debated, mainly focusing on the advantages and disadvantages provided by the choice of natural, simulated or artificial records. However, most of the available technical codes do not provide always the same suggestions and well-defined procedures for the generation of artificial ground motions. Considering that the strategy of the generation of accelerograms makes some doubts raise about the possible effect on the structural response, the work aims to investigate on the differences of the structural behavior by using accelerograms nominally equivalent but different in terms of stationarity. This paper presents a compar…
A model for SFRC beams without shear reinforcement
2008
In this paper a physical model, for the prediction of ultimate shear strength of Steel Fibers Reinforced Concrete (SFRC) beams is developed from the plastic Crack Sliding Model (CSM) introduced by Zhang (1997), based on the hypothesis that cracks can be transformed into yield lines. In this work the effectiveness factors are recalculated for SFRC beams and some further developments are introduced in the CSM, taking into account the fundamental post cracking tensile strength contribute of SFRC. The proposed model is validate by a large set of tests collected in literature and some numerical analyses were carried out to show the influence of fibers on the failure beams mode.
Comportamento flessionale di nodi esterni in calcestruzzo fibrorinforzato
2010
A softened strut-and-tie macro model able to reproduce the flexural behavior of external beam-tocolumn joints with the presence of horizontal and vertical steel bars, including softening of compressed struts and yielding of main and secondary steel bars, is presented, to be used for the pushover analysis. The model proposed is able to calculate also the flexural response of fibrous reinforced concrete (FRC) beam-to-column sub-assemblages in term of a multilinear load-deflection curves. The model is able to take into account of the tensile behavior of main bars embedded in the surrounding concrete and of the softening of the compressed strut, the arrangement and percentage of the steel bars,…
Out of plane fragility of infill walls with and without prior in-plane damage
2019
The paper presents the results of a probabilistic assessment framework aimed at evaluating out-of-plane fragility curves of infill walls which have suffered (or not) prior in-plane damage. Out-of-plane incremental dynamic analyses are performed based on a suite of 22 ground motion records. A recently developed in-plane / out-of-plane macroelement model is used to model masonry infills within frames. The outcomes show fragility curves representing the probability of exceeding out-of-plane collapse at a given earthquake intensity as a function of a different combination of geometrical and mechanical parameters, in-plane damage level and supporting conditions.
Behavior in compression of lightweight fiber reinforced concrete with hooked steel fibers and transverse steel reinforcement
2010
Shear-flexure interaction of RC elements strengthened with FRP sheets
2005
An approximate physical model for evaluation of the M-V interaction resistance domains for concrete elements strengthened with FRP sheets is presented. The reliability of the model in predicting flexureshear capacity is verified by a comparison with the results of several experimental tests.
RC Masonry infilled frames: Experimental results and development of predictive techniques for the assessment of seismic response
2014
La presenza di tamponamenti in muratura all’interno delle maglie di strutture intelaiate induce, in presenza di azioni laterali, una sostanziale modificazione della risposta globale rispetto a quella dei telai nudi in termini di rigidezza, resistenza e capacità di spostamento. La tesi presenta i risultati di una campagna sperimentale su telai tamponati con diverse tipologie di muratura soggetti a prove di carico cicliche. Successivamente viene proposto un criterio per la modellazione semplificata del comportamento ciclico attraverso un macromodello a puntone diagonale equivalente. Una ulteriore indagine numerica è eseguita per valutare l'entità degli effetti locali dovuti all'interazione fr…
STRUCTURE, ENVELOPE AND TECHNOLOGICAL INNOVATION The reinforced concrete in the construction of very tall buildings
2014
Until the second half of the nineteenth century, ie until the Industrial Revolution, the building structures played static function and also protective function. In the course of time separating the combination goes. The introduction of iron leads to a progressive "innovation" of building structures. The first application of iron in construction dates back to the mid-nineteenth century. They were first made with cast-iron columns and beams in iron and later with particular types of steel. The architecture of the iron is a true regeneration of the way of building, the cities are filled with sophisticated solid structures and slim at the same time, it enhances the transparency of glass, it in…
Cupole in cemento armato in Sicilia occidentale nella prima metà del Novecento
2014
The paper intends to examine through three case studies the change introduced by the technology of reinforced concrete in the construction of domes. After a brief description of the geometric and architectural characteristics of reinforced concrete domes, the study focuses on three interventions, for which a considerable archival documentation was collected. Chronologically the first intervention is related to the construction of the dome of the mother-church of Bisacquino (1923-25), built on the basis of the architectural project and under the direction of the engineer Pietro Scibilia. The second concerns the reconstruction of the dome of Sant’Ignazio martire all'Olivella church in Palermo…
Some recent results on the compressive and flexural behaviour of composite members
2005
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. Simpli…