0000000000975908
AUTHOR
Salvatore Pagnotta
showing 12 related works from this author
Influence of Cross-Section Shape and FRP Reinforcement Layout on Shear Capacity of Strengthened RC Beams
2022
The evaluation of the shear capacity of an FRP-strengthened reinforced-concrete beam is challenging due to the complex interaction between different contributions provided by the concrete, steel stirrup and FRP reinforcement. The shape of the beam and the FRP inclination can have paramount importance that is not often recognized by the models that are suggested by codes. The interaction among different resisting mechanisms has a significant effect on the shear capacity of beams, since it can cause a reduction in the efficiency of some resisting mechanisms. A comparative study of the performance in the shear resistance assessment provided by three models with six different effectiveness fact…
Vulnerabilità ed esposizione sismica del costruito residenziale del centro storico di Alcamo
2021
Vulnerabilità ed esposizione dell'edilizia residenziale del centro storico di Alcamo
Comparison of fully non-stationary artificial accelerogram generation methods in reproducing seismicity at a given site
2020
Abstract Seismic input modelling is a crucial step when Non-Linear Time-History Analyses (NLTHAs) are performed, the seismic response of structures being highly responsive to the input employed. When natural accelerograms able to represent local seismicity are not available, the use of generated accelerograms is an efficient solution for input modelling. The aim of the present paper is to compare four methods for generating fully non-stationary artificial accelerograms on the basis of a target spectrum, identified using seven recorded accelerograms registered in the neighbourhood of the construction site during a single event, assumed as target accelerograms. For each method, seven accelero…
Effect of the different data survey scale on assessment of seismic exposure and vulnerability of the historic center of Caltabellotta
2019
The results of the prediction of exposure and seismic vulnerability for the buildings of the historic center of Caltabellotta, obtained with databases of different levels of accuracy, are compared. In particular, the results obtained on the basis of the estimation of the characteristics and of the distribution of the typologies derived from the filling in of the CARTIS sheets on a sector scale are compared with those obtained through a survey from the outside to a building scale. In this latter area, indicators contained in the CARTIS are suitably supplemented with those available in the literature, partly modified to adapt them to the local reality. The vulnerability is evaluated on the ba…
Shear Capacity Model with Variable Orientation of Concrete Stress Field for RC Beams Strengthened by FRP with Different Inclinations
2021
A design-oriented analytical model able to evaluate the shear capacity of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) sheets or strips oriented in any direction is proposed. The formulation of the model is based on the variable-inclination stress-field approach, aiming to extend the provisions of current European standards to beams strengthened in shear using FRP. The main novelty of the model lies in taking into account the possible different inclination of steel stirrup and FRP reinforcement in determining the orientation of a compressed concrete stress field, and in shear strength evaluation, overcoming the approximation of the known models with variab…
Design of RC joints equipped with hybrid trussed beams and friction dampers
2021
Abstract The challenge of this research consists in the first attempt to apply a dissipative friction connection to beam-to-column joints with semi-prefabricated Hybrid Steel-Trussed Concrete Beams (HSTCB) and RC pillars cast in-situ. Nowadays, HSTCBs are widely adopted in civil and industrial buildings and, therefore, it is required to evaluate their compliance with the capacity design criteria and their seismic energy dissipation capability. However, the design of the reinforcement of such beams usually lead to the adoption of large amount of steel within the panel zone which becomes potentially vulnerable to the effects of seismic cyclic actions and dramatically reduce the dissipation ca…
Seismic Performance of Earthquake-Resilient RC Frames Made with HSTC Beams and Friction Damper Devices
2021
Seismic behavior of RC frames with hybrid steel-trussed concrete beams is affected by panel zone damage due to a large amount of longitudinal reinforcement. Here the seismic efficiency of innovative frames characterized by friction damper devices (FDDs) at beam-to-column connections is compared against traditional frame. Three configurations are investigated: FDDs alone; FDDs with column-to-foundation connections having preloaded threaded bars and disk springs; FDDs with self-centering friction devices. Non-linear analyses show that FDDs alone prevent plastic hinge formation at beam ends and beam–column joint damage. FDDs with self-centering friction devices effectively limit both peak and …
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…
RC beams retrofitted by FRP oriented in any direction: Influence of the effectiveness factors
2022
Shear strength of FRP-retrofitted RC beams is usually influenced by different brittle failure modes characterizing the collapse of the FRP reinforcement. The most significant analytical models for assessing the shear strength of FRP-retrofitted RC beams reflect the effect of brittle failure through an effectiveness factor “R”, which reduces the ultimate tensile strength of FRP. The brittle collapse of FRP reinforcement often leads to a lower shear contribution by steel stirrups due to hindering of the yielding of all stirrups involved by critical cracking. Some analytical models consider this phenomenon introducing a further effectiveness factor “r”, which reduces the yielding strength of s…
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.
Design of friction connections in R.C. structures with hybrid steel-trussed concrete beams
2019
In this work a feasibility study on the use of friction devices within beam-to-column joints of RC structures is conducted. The connection is made between RC columns cast in-situ and semi-prefabricated steel-concrete beams, named Hybrid Steel-Trussed-Concrete Beams (HSTCBs). Nowadays, HSTCBs are widely adopted in civil and industrial buildings and, therefore, it is required to evaluate their compliance with the capacity design criteria and their seismic energy dissipation capability. However, the design of the reinforcement of such beams usually lead to the adoption of large amount of steel within the panel zone which becomes potentially vulnerable to the effects of seismic cyclic actions a…
Design of innovative friction damper devices for earthquake-resilient RC frames with Hybrid Steel-Trussed Concrete Beams
2021
This thesis focuses on the design of innovative friction damper devices for earthquake-resilient Reinforced Concrete (RC) frames realized with Hybrid Steel-Trussed Concrete Beams (HSTCBs). These devices fall within the framework of the recently-proposed low-damage design strategy for structures built in earthquake-prone areas, on the basis of which the structures are designed to experience negligible damage when subjected to seismic events. The comprehensive solution proposed aims at introducing a feasible option for building earthquake-resilient RC Moment Resisting Frames (MRFs), having been proposed very few solutions for this structural scheme so far. Innovative solutions are proposed fo…