Search results for "aeroporti"
showing 10 items of 387 documents
Il contesto infrastrutturale siciliano e il quadro normativo di riferimento
2014
Il volume intende illustrare il tema della sicurezza stradale nelle sue molteplici dimensioni e in maniera trasversale, con uno specifico approfondimento per la Sicilia, mettendo a disposizione un'ampia selezione di informazioni qualitative e quantitative per specifiche analisi sulla sicurezza stradale, utili ai policy maker per intraprendere azioni di programmazione a livello locale. L'Italia registra un elevato tasso di mortalità rispetto alla media europea, una lenta riduzione del numero di vittime per incidente stradale e marcati divari territoriali. Nel contesto nazionale questo studio descrive poi l'evoluzione del fenomeno dell'incidentalità in Sicilia nell'ultimo decennio, individuan…
Criteria for Laboratory Studies on Fine Soils Treated with Lime
2011
When selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating those natural soils that, involved in the earthwork for opening road fences, are not suitable, as they are in nature, to fulfill the specific requirements for being used as part of road construction, such as road embankments (including the capping layer) or the improved subgrade or, again, the sub-formation. From this point of view, the treatment of fine soils with lime (if needed, with lime and cement) can be considered as one of the main measures for preserving the natural environment since it fulfi…
Estimation of Air Pollutant Emissions in “Turbo” and in Conventional Roundabouts
2013
The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the turbo roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the performances and the pollutant emissions into turbo roundabouts. A comparative analysis between conventional roundabout and turbo round…
Rheological investigation on the ageing performance of bio-recycled asphalt binders and mixtures
2023
The current need to move towards more sustainable technologies in the construction sector has promoted the investigation of using alternative materials in asphalt mixtures for pavements. Biomaterials, used as biobinders, have shown their potential as partial replacement of bitumen in asphalt mixtures as solution to decreasing the demand for fossil-fuel-based binders as well as CO2 emissions. However, more research is needed to increase the replacement of bitumen in asphalt mixtures. In this investigation,biobinders are used as full replacement of virgin bitumen and as recycling agent within asphalt mixtures with high Reclaimed Asphalt (RA) content. Blends of biobinders and RA binders, and b…
An italian research on mechanical properties on asphalt with tire-rubber
2003
In Palermo a research study was initiated with following objectives: characterisation of the asphalt with tire rubber; study of pavements overlaid with this type of asphalt; cost estimation of asphalt rubber production process. This paper describes the first results achieved in the study concerning the mechanical properties of asphalt with tire rubber for road base and base course. In this research on dry process, more than 400 specimens have been tested at the DIIV laboratory for analysing the influences of crumb rubber modifier and powdered rubber modifier on the Marshall and indirect tensile test.
EXPERIMENTAL INVESTIGATION ON DRY ASPHALT RUBBER FOR SUBBALLAST
2011
The asphalt rubber mixes have a wide application field in the railroad and road superstructures because of their technical and environmental properties. While in many countries the wet process is often used to make bituminous mixtures, the dry process doesn’t have the same degree of application even though a larger recycling of waste tires rubber is allowed than the dry process. This paper focuses on the mix-design of the Dry Asphalt Rubber (DAR) for subballast of the railroad superstructure in order to define a sound laboratory procedure of mix-design with reference to Marshall test and Superpave Gyratory Compactor (SGC) test. The comparison between Marshall test and SGC test highlights th…
Morfologia ed analisi delle immagini applicate allo studio dei bitumi modificati con polimeri
2009
Vengono presentati i risultati di uno studio di laboratorio condotto su campioni di bitume modificato con diversi tipi di polimeri e precisamente Stirene-butadienestirene (SBS), Etilen-vinilacetato (EVA) ed etilen-butilacrilato (EBA), le cui proprietà fisico-chimiche vengono riportate nell’articolo.
PG dei bitumi stradali per il territorio italiano
2010
L’ARTICOLO SINTETIZZA IL LAVORO DI RICERCA SVOLTO DALL’UNIVERSITÀ DI PALERMO PER DEFINIRE - SU BASE TERRITORIALE NAZIONALE - LE TEMPERATURE CARATTERISTICHE DETERMINANTI PER LA QUALIFICAZIONE DEI BITUMI, CONFORMEMENTE ALLE SPECIFICHE SUPERPAVE. NE SONO DERIVATE CARTE TEMATICHE DELLE TEMPERATURE MASSIME E MINIME DI PROGETTO DELLE PAVIMENTAZIONI STRADALI CHE I TECNICI POTRANNO UTILIZZARE PER LA SELEZIONE DEI LEGANTI BITUMINOSI.
Valutazione di laboratorio delle caratteristiche di resistenza a fatica dei conglomerati bituminosi contenenti fresato - Laboratory Evaluation of Fat…
2008
Gli Autori presentano i risultati di uno studio mirato alla messa a punto di un nuovo metodo di prova per la valutazione in laboratorio della resistenza agli sforzi tangenziali dei conglomerati bituminosi destinati a costituire strati d’usura. Alla base di un tale sviluppo prototipale, vi è la considerazione della meccanica del contatto pneumatico-pavimentazione, al fine di riprodurre nel modo più realistico possibile l’effetto della sollecitazione tangenziale generata in corrispondenza di punti singolari, dato che proprio per questi punti è più difficile riprodurre in laboratorio la degradazione superficiale cui sono soggetti.
Experimental characterization of asphalt for an elasto-visco-plastic constitutive model.
2007
This paper describes a range of uniaxial creep tests that have been undertaken for a proprietary polymer modified asphalt, the procedure used to determine the parameters required for an elasto-visco-plastic constitutive model. Uniaxial compressive creep testing and creep recovery testing have been undertaken over a range of temperatures and stress conditions. Procedures used to determine the model parameters from the test data are detailed and parametric equations are developed to describe the model parameters as functions of the test conditions. Particular attention is given to the determination of the parameters related to visco-plastic flow and damage accumulation at high strain levels. …