Search results for "CONFINEMENT"

Experimental investigation on the effectiveness of basalt-fibre strengthening systems for confining masonry elements

L’impiego di materiali compositi per il rinforzo di colonne in muratura è diventato una pratica ampiamente diffusa nel corso degli ultimi decenni. Questa tecnica, che consiste generalmente nell’applicazione di materiali polimerici fibrorinforzati (Fibre Reinforced Polymer-FRP), ha mostrato buone potenzialità, essendo in grado di garantire notevoli incrementi di resistenza e duttilità dell’elemento rinforzato, grazie ad un’azione di confinamento passivo. Tuttavia, l’impiego di compositi a matrice polimerica presenta alcuni limiti legati soprattutto alle prestazioni delle resine epossidiche, che a causa della loro natura sintetica danno luogo a problemi di compatibilità con il supporto murari…

Compressive response of substandard steel-jacketed RC columns strengthened under sustained service loads: From the local to the global behavior

2018

Abstract This paper presents an experimental investigation on substandard partially steel jacketed RC columns strengthened under sustained loads and loaded until failure. The aim of the study is to compare the compressive response of preloaded columns with respect to the tests without preload to obtain a more realistic prediction of load-carrying capacity of structural columns after retrofitting under serviceability loads. The influence of the preload level, the delayed contribution of the confining device during the loading process and the time dependent effects are highlighted for the tested specimens. Based on the experimental observations, an analysis-oriented model is proposed for the …

Stress-Strain Law for Confined Concrete with Hardening or Softening Behavior

2013

This paper provides a new general stress-strain law for concrete confined by steel, fiber reinforced polymer (FRP), or fiber reinforced cementitious matrix (FRCM), obtained by a suitable modification of the well-known Sargin’s curve for steel confined concrete. The proposed law is able to reproduce stress-strain curve of any shape, having both hardening or softening behavior, by using a single closed-form simple algebraic expression with constant coefficients. The coefficients are defined on the basis of the stress and the tangent modulus of the confined concrete in three characteristic points of the curve, thus being related to physical meaningful parameters. It will be shown that if the v…

A three-dimensional study of the onset of convection in a horizontal, rectangular porous channel heated from below

2012

Author's version of an article published in the journal: International Journal of Thermal Sciences. Also available from the publisher at: http://dx.doi.org/10.1016/j.ijthermalsci.2011.12.012 The onset of convection is studied in a rectangular channel filled with a fluid saturated porous medium, bounded above and below by impermeable isothermal walls at unequal temperatures and laterally by partially conducting walls. A three-dimensional linear stability analysis is carried out under the assumption of an infinite longitudinal channel length. Then, this assumption is relaxed in order to determine the threshold length for the three-dimensional convection to be the preferred mode at onset. Sens…

The impact of strict and forced confinement due to the COVID-19 pandemic on positive functioning variables, emotional distress, and posttraumatic gro…

2021

ABSTRACT Background: The adverse consequences of the COVID-19 pandemic on mental health have been widely studied in recent months. However, few studies have examined the protective psychological factors that may explain how individuals are coping with the COVID-19 pandemic and its forced confinements. Objective: This study analyzes the impact of confinement due to the COVID-19 pandemic on positive functioning variables (resilience, meaning of life, gratitude, compassion, life satisfaction), emotional distress (depression, anxiety, perceived stress, affect), and posttraumatic growth (PTG). The impact was measured during and after the first month of strict and obligatory confinement in Spain.…

Effects of confinement level, cross-section shape and corner radius on the cyclic behavior of CFRCM confined concrete columns

2014

Abstract The main results of an experimental research aiming to investigate the behavior of medium-size low-strength concrete columns wrapped with Carbon Fiber Reinforced Cementitious Matrix (CFRCM) under monotonic and cyclic compressive axial loads are presented. Thirty columns with circular, square and rectangular cross-sections were tested under monotonic and cyclic axial loads to investigate the effect of the confinement level, the cross-section shape and the corner radius on the stiffness, strength, and ductility of CFRCM confined concrete columns under cyclic loads. The results prove that CFRCM confining jackets provide substantial gain in compressive strength, deformability and absor…

La responsabilité des professionnels de santé face au tri des patients : dilemme éthique ou question juridique ?

2022

International audience

Institution en temps de crise

2023

Épopée clinique de survie d’une institution, ce travail original issu d’une recherche-action apporte des éléments de compréhension nouveaux sur ce qui se passe lors d'un choc exceptionnel et également des pistes pour penser concrètement la résilience collective.Sorte d’épopée clinique de survie d’une institution, cet ouvrage original, issu d’une recherche-action, apporte des éléments de compréhension nouveaux sur ce qui se passe lors d'un choc exceptionnel, et des pistes pour penser concrètement la résilience collective.Dans cet établissement accueillant des personnes souffrant d’un handicap psychique, le temps arrêté pour laisser le virus s’éloigner a généré une vie émotionnelle intense, t…

Moment-Axial Domain of Corroded R.C. Columns

2018

In the present paper, a simplified model to determine the moment-axial force domain of the cross-section of reinforced concrete columns subjected to corrosion process is presented. The model considers members with square and rectangular cross-sections and it accounts for cover spalling, buckling of longitudinal reinforcing bars, loss of bond of bar in tension, reduction of confinement pressures (due to the reduction of the area of stirrups and cracking of concrete induced by rust formation). The analytical expressions for prediction of the area reduction of steel, bond strength and critical load of longitudinal bars utilized were verified against experimental data available literature.

Lactic acid bacteria strains for bioprotection application with cells entrapment in biopolymeric matrices

2013

Among the various methods to control foodborne pathogenic and/or food spoilage microorganisms in food chain, bioprotective lactic acid bacteria (LAB) appear to be promising tools for food biopreservation. This collaborative study, between PAPC (Agrosup Dijon, University of Burgundy) and BioDyMIA (University Lyon1-Lyon Isara) laboratories, concerned the development of sodium alginate/sodium caseinate polymeric matrices intended to entrap LAB cells selected for their anti-Listeria spp. activity. First, 4 LAB strains from 19 LAB strains were selected for their anti-Listeria spp. activity: this screening was performed by the method of agar diffusion against three Listeria spp strains. Then, ant…