Search results for "stirrups"
showing 9 items of 9 documents
Shear models of Rc-encased steel joist beams in MRFs
2019
This study presents the application of different analytical and finite element (FE) models aimed at predicting the shear resistance of reinforced concrete (RC) and reinforced concrete-encased steel joist (HRCESJ) beams with inclined transversal reinforcement in moment resisting frames (MRFs). In particular, four analytical models are taken into account, two of them specifically conceived for HRCESJ beams in seismic area. The analytical models considered are Eurocode-2 model for the shear strength of RC beams; a variable-inclination stress-field approach; a strut-and-tie additive model and, finally, an analytical formulation in which the shear capacity depends on the number of pairs of incli…
Shear capacity in concrete beams reinforced by stirrups with two different inclinations
2014
Abstract A model for the estimation of shear capacity in Reinforced Concrete (RC) beams with web reinforcement is provided by introducing a generalization of classical plastic Nielsen’s model, which is based on the variable-inclination stress-field approach. The proposed model is able to predict the shear capacity in RC beams reinforced by means of stirrups having two different inclinations and longitudinal web bars. A numerical comparison with the results of experimental tests and those provided by a Finite Element Model (FEM) based on the well known theory of Modified Compression Field Theory (MCFT) is carried out for validating the robustness of the proposed model. Finally, a set of para…
Shear resistance analytical evaluation for RC beams with transverse reinforcement with two different inclinations
2020
An analysis-oriented mechanical model for shear strength evaluation of Reinforced Concrete (RC) beams with transverse reinforcement with two different inclinations, which required a numerical analysis, is turned into a design-oriented analytical model that can easily be utilized for practical purposes. The model assessed the shear resistance, according to the “lower-bound solution”, employing a numerical procedure that maximizes the element shear strength varying the stresses in the two sets of transverse reinforcement and the magnitude and inclination of the web concrete compressive stress field. The model is formulated with the aim of representing an extension of Eurocode 2 framework to R…
Steel fiber-reinforced concrete corbels:experimental behavior and shear strength prediction
2007
Corbels are structural members often used in reinforced concrete structures to transfer vertical and horizontal forces to principal members. This paper presents experimental research regarding the flexural behavior of corbels in plain and fibrous concrete and in the presence of steel bars. The study considers the influence of the type of concrete grade (normal- and high-strength concretes), of the fiber percentage and of the arrangement and percentage of the steel bars on the flexural behavior of the corbels. The results in terms of load-deflection curves and crack patterns show the effectiveness in using fibrous reinforced concrete corbels as well as in the presence of stirrups ensuring ad…
Ultimate Shear of RC Beams with Corroded Stirrups and Strengthened with FRP
2019
Transverse reinforcement plays a key role in the response behavior of reinforced concrete beams. Therefore, corrosion of steel stirrups may change the failure mode of elements from bending to shear, leading to a brittle and catastrophic crisis. It is important to strengthen reinforced concrete beams with corroded stirrups to enhance the shear resistance. This paper presents a formulation, based on the modified compression field theory, to estimate the ultimate shear of reinforced concrete beams strengthened with FRP, because of stirrup corrosion. The detrimental effect of corrosion on steel stirrup yield strength was taken into account by introducing an empirical decay law. The effective st…
Modello Esplicito Per La Resistenza A Taglio Di Travi In C.A. Con Armature Trasversali Disposte Secondo Due Giaciture
2016
An analysis oriented mechanical model for shear strength evaluation of rc beams with transversal reinforcement with two different inclination, that required a numerical analysis, is tuned into a design oriented analytical model that can be handy utilized for practical design.
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.…
SHEAR RESISTANCE OF R/C BEAMS PROVIDED WITH DIFFERENTLY-INCLINED TRANSVERSE REINFORCEMENT
2012
The model for the evaluation of shear resistance of reinforced concrete member provided with transverse web reinforcement, derived by Nielsen (1999) on the basis of the variable inclination stress field approach, is generalized here to predict the shear strength of r.c. beams equipped with two sets of differently-inclined transversal web reinforcement and longitudinal skin reinforcement. Numerical analyses emphasize the efficiency of double inclined web transverse reinforcement in providing shear strength to beams.
Validation of a Shear Model for RC and Hybrid Beams with Two Different Inclinations of Transversal Reinforcement
2016
The validation of an analytical model recently proposed for evaluation of the shear capacity in Reinforced Concrete (RC) beams containing multiple inclination of transverse stirrups is presented. The model is a suitable extension of that currently proposed in Eurocode 2 for the evaluation of the shear resistance, and it is derived by means of the the variable-inclination stressfield theory based on Nielsen’s plastic approach. Experimental and numerical data available in the literature on Hybrid Steel-Trussed Concrete Beams (HSTCBs) are used for model validation and result discussion. Finally, also the comparison with a different analytical approach for the assessment of the shear resistance…