Search results for "concrete"

showing 10 items of 262 documents

Calcestruzzi rinforzati con fibre di PET. Sperimentazioni sull'impiego delle fibre di PET provenienti dalla raccolta differenziata nella produzione d…

2013

La sperimentazione esposta tratta dell’impiego di fibre di PET, ricavate dal semplice taglio di contenitori per bevande, nel rinforzo di calcestruzzi destinati anche a impieghi strutturali. Indaga la durabilità delle fibre in ambiente fortemente basico e le caratteristiche meccaniche di calcestruzzi rinforzati con differenti dosaggi di fibre. Le osservazioni al microscopio elettronico a scansione (SEM) di fibre di PET immerse per 13 giorni a 65°C in acqua distillata e in due soluzioni fortemente basiche mostrano la buona durabilità delle fibre in soluzione 0,103 M di NaOH, che simula la basicità della soluzione acquosa che permea la matrice cementizia. L’influenza delle fibre e del loro dos…

durabilitàcaratteristiche meccanichesostenibilità calcestruzzi speciali FRC fibre di PETFiber-reinforced concretePET bottleAlkali resistanceSettore ICAR/10 - Architettura TecnicaSettore ICAR/11 - Produzione Ediliziamechanical propertiesPET fiberDurability
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Il modulo elastico statico e dinamico del calcestruzzo

2012

elastic behavior of concreteSettore ICAR/05 - TrasportiHipothesis testing of statistic correlations.Settore SECS-S/01 - StatisticaStatic and dynamic modulus of elasticity
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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…

experimental tests composite columns fiber reinforced concrete
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¿Cabe hablar de una «generación de la crisis»? Discusión en torno a una noción sobreexplotada

2018

This article states that nowadays there is an overuse (or a misuse) of the «Generation» idea. The discussion among many authors over the «Generation of crisis» concept suggests that it is useful to outline the characteristics of the target of population of the collective of youth who are mainly affected by the economic and social crisis over the past years. Nevertheless, through analyzing the meanings of the «Generation of Crisis» made by Mannheim, Ortega and other classic authors, it is clear that the social class approach together with the generational one are needed to define this concrete concept. The conclusion of the articleis that both approaches are seen as underpinning their utilit…

generationsMarianoyouthsocial classesgeneracionesAlmudena This article states that nowadays there is an overuse (or a misuse) of the «Generation» idea. The discussion among many authors over the «Generation of crisis» concept suggests that it is useful to outline the characteristics of the target of population of the collective of youth who are mainly affected by the economic and social crisis over the past years. NeverthelessEspañaMoreno MínguezOrtega and other classic authors:SOCIOLOGÍA [UNESCO]the function of the notion of generation in sociology (particularly in the sociology of youth) is claimed without using it in order to hide conflicts and inequalities (due to other elements of the social fragmentation) that arise in each of the «generations» andcrisisUNESCO::SOCIOLOGÍAthrough analyzing the meanings of the «Generation of Crisis» made by Mannheimit is clear that the social class approach together with the generational one are needed to define this concrete concept. The conclusion of the articleis that both approaches are seen as underpinning their utility to the study of the dynamics of social change (even generational) occurring in the postcrisis society which will also reinforce their impact. Besidestherefore1137-7038 8537 Arxius de sociologia 493757 2018 38 6508347 ¿Cabe hablar de una «generación de la crisis»? Discusión en torno a una noción sobreexplotada Urraco Solanillaclases socialesin the contemporary capitalist societies. juventudSpain. 79 92
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Towards resilient cities: Advancements allowed by a multi-criteria optimization tool to face the new challenges of European Union’s climate and energ…

2019

Abstract The United Nations as well as the European Union are strongly committed in promoting a transition towards more sustainable and resilient cities. Indeed, they are increasingly affected by different types of threats, among which the natural ones such as earthquakes, fires, and floods (shocks) and climate variability (stresses). Cities are quite often unable to cope with the adverse effects of such natural hazards. This circumstance leads to the need of introducing resilience-related criteria (besides commonly used sustainability indicators) in decision-making processes. This paper investigates at which extent the inclusion of such new indicators, within multi-criteria assessment tool…

green roofEnergy (esotericism)cool roofGreen roofFace (sociological concept)Indoor air pollutionHistoric preservationEnergy conservationmulticriteria assessmentEnvironmental protectionMulti criteriaSustainable developmentmedia_common.cataloged_instanceEuropean unionResilience (network)Concrete pavementsEnvironmental planningmedia_commonMultiobjective optimizationResiliencePublic administrationAir quality; Concrete pavements; Decision making; Energy conservation; Environmental protection; Historic preservation; Indoor air pollution; Multiobjective optimization; Public administration; Sustainable developmentAHP methodAir qualityBusinesspriority-setting process.Decision making
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Mathematical modelling of sustainable bioresidual concrete

2019

In the production of cement, which is the main component of concrete production, the process generates about 5% of the global carbon dioxide emissions. In addition, bioproduct and pulp mills produce signi_cant quantities of soda ash and bio-ash, which is still largely unused. In this paper we will introduce our study related to improving the environmental friendliness of concrete used in construction by utilizing pulp mill waste while its long-term durability and strength and porosity properties meet the goals set for construction. The project `sustainable bioresidual concrete' is on-going and only preliminary numerical results with measurements are presented here. peerReviewed

hiilidioksidiympäristöystävällisyysbetonifinite element methodconcretecarbon dioxidemathematical modellingkestävyysmatemaattiset mallitsustainabilitysementti
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Il calcestruzzo poroso per il miglioramento delle condizioni di stabilità dei pendii sede di falda idrica

2022

Reduction of pore water pressures is a useful strate-gy to improve the stability conditions of slopes. Deep draining trenches can be used for this scope. For the realisation of deep trenches, the usual con-ventional construction techniques are not adequate and the use of adjacent vertical panels, built by means of the methods well established for dia-phragm walls, is necessary. However, unbonded ma-terials (i.e. gravels) cannot be used, since the excava-tion of a panel adjacent to already built ones will cause instability. For this scope a bonded material such as the pervious concrete can be used. It must have high permeability, filtering capacity in order to prevent the internal erosion of…

interface shear strengthPervious concreteSettore ICAR/07 - Geotecnicashear keys effect.
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La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde

2022

Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…

interface shear strengthPervious concreteSettore ICAR/07 - Geotecnicashear keys effect. Pervious concrete for deep trench drains used to stabilise slopes must simultaneously satisfy many requirements namely adequate hydraulic conductiv-ity adequate shear strength a few days after pour-ing capacity to act as a protective filter for soils in which the drain is installed good resistance to clog-ging and adequate residual hydraulic conductivity. The pervious concrete with appropriated mix-design can effectively satisfy all the abovementioned requirements. If the trenches depth is such that they intersect the sliding surface and if the trenches are adequate-ly "socket" in the layers of stable soil there is a fur-ther increase in shear strength due to the shear keys effect. This latter is in addition to the increase in shear strength resulting from the reduction of inter-stitial pressures that remains the principal scope of the draining trenches. Obviously the increase of shear strength due to the shear keys effect occurs if the trenches are filled with material that have enough strength and stiffness such as the porous concrete. In this case the beneficial effects of the draining trenches on stability are also due to the resistance at the concrete interface of the trench - soils and to the intrinsic resistance of the concrete at the area of the trench intersected by the sliding surface taken into consideration.The increase in resistance due to the shear keys effect can be very significant in relation to the thickness and interspace of the trenches. Results reported in the paper demonstrated that the interface fine grained soil-pervious concrete is higher than the residual shear strength of the soil.
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Failure Load and Collapse Mode of an RC Beam in a Large Collapsed Roof

2021

The present work focused on the determination of the collapse load and of the failure mode of a collapsed framed structure constructed in the South of Italy and failed in 2004 under its self-weight. Information available was the results on extensive experimental test campaign, for the determination of mechanical properties of concrete and steel bars of beams, floors and columns involved in the failure. Moreover, draws of original design with construction details and design rules valid in Italy at the time of construction were found. A simple monodimensional beam model for prediction of load-deflection curve, able to include degradation of constituent materials (concrete, steel and bond) was…

material degradationbusiness.industryCollapse (topology)analytical modelBuilding and ConstructionStructural engineeringReinforced concreteCollapse modefailureSettore ICAR/09 - Tecnica Delle CostruzioniArts and Humanities (miscellaneous)Material DegradationBuildingnumerical modelbusinessRoofFailure mode and effects analysisGeologyBeam (structure)RCCivil and Structural EngineeringPractice Periodical on Structural Design and Construction
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On the Fundamental Period of Infilled RC Buildings

2015

This paper investigates the fundamental period of vibration of RC buildings by means of finite element macro-modelling and modal eigenvalue analysis. As a base study, a number of 14-storey RC buildings have been considered \"according to code designed\" and \"according to code non-designed\". Several parameters have been studied including the number of spans; the span length in the direction of motion; the stiffness of the infills; the percentage openings of the infills and; the location of the soft storeys. The computed values of the fundamental period are compared against those obtained from seismic code and equations proposed by various researchers in the literature. From the analysis of…

modal analysiinfilled framemasonryfundamental periodreinforced concrete buildings
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