Search results for "Ferro"

Indagine di laboratorio sulla permeabilità dei conglomerati bituminosi aperti

2010

I conglomerati bituminosi aperti utilizzati nelle pavimentazioni drenanti-fonoassorbenti devono garantire in opera precise e specifiche prestazioni in termini di conducibilità idraulica e rifrazione acustica, la cui quantificazione è demandata a indagini da effettuare “a posteriori” sulla sovrastruttura già realizzata. Questa prassi, registrata e regolata dai principali e più significativi Capitolati speciali per opere stradali, mostra un notevole limite qualora si voglia stabilire “a priori” il livello di prestazione del conglomerato, misurando il valore della grandezza in esame - per esempio la permeabilità - già in ambito di laboratorio e progettando di conseguenza la miscela, intervenen…

Modellazione FEM del comportamento visco-elastoplastico di conglomerati bituminosi per uso stradale

2010

In questo lavoro si è voluto formulare un modello per descrivere il comportamento meccanico del conglomerato bituminoso di uso stradale che può essere facilmente implementato in programmi software FEM di uso comune, al fine di effettuare una rigorosa analisi strutturale delle pavimentazioni flessibili. Dopo una breve rassegna dei modelli costitutivi esistenti, a partire dai più semplici fino ai più complessi, è possibile concludere che un corretto metodo di modellazione consiste nel dividere la risposta del materiale, in termini di deformazione totale, nelle diverse componenti e di descriverle tutte separatamente. Nel confronto con i risultati sperimentali, il modello proposto è in grado di…

Prestazioni migliorate con additivi polimerici

2017

IMPIEGARE I MATERIALI DISPONIBILI SUL TERRITORIO E AD UN TEMPO GARANTIRE ELEVATE PERFORMANCE E DURABILITÀ, NONCHÈ CANTIERABILITÀ ANCHE IN CONDIZIONI CLIMATICHE ESTREME: È LA GRANDE SFIDA DELL’”OTTIMIZZAZIONE” DELLE PAVIMENTAZIONI STRADALI VINTA DALL’INGEGNERIA DEI MATERIALI CON L’AIUTO DEI COMPOUND CONTENENTI POLIMERI. DI SEGUITO, L’ILLUSTRAZIONE DI UN CASO ESEMPLARE DI MODIFICA MIGLIORATIVA DI MISCELE BITUMINOSE, GIÀ PRESENTATO AL RECENTE CONGRESSO TIS 2017 DELL’AIIT A ROMA.

Experimental Survey on Dry Asphalt Rubber Concrete for Sub-ballast Layers

2012

The railway traffic through a town or near built-up areas causes heavy effects such as noise and vibration on surroundings. In order to minimize the level of these impacts the railway companies with researchers and practitioners seek suitable solutions especially in the field of the rail-track because the main source of the ground borne vibrations and noise is the bad wheel-track contact. In particular, a big effort is addressed to new materials with high mechanical and environmental performance that can be utilized within the sub-ballast layer. This paper presents the results of an experimental survey on the potential application of Dry Asphalt Rubber Concrete (DARC) in sub-ballast layers …

DAMPING AND MECHANICAL PROPERTIES OF DRY ASPHALT RUBBER FOR SUB-BALLAST LAYERS

2011

The passage of railway lines through a town or near built-up areas poses serious environmental problems such as noise and vibration. Consequently railway companies have shown an increasing interest in developing new materials with high mechanical and environmental performance. This paper presents the results of an experimental research on the potential application of Dry Asphalt Rubber (DAR) in sub-ballast layers by measuring its damping and mechanical properties. An experimental survey based on four point bending and Marshall tests was carried to measure the stiffness modulus and damping ratio both of a standard bituminous mixture and of dry asphalt rubber mixture with a rubber content equ…

Mobile Mapping System: case study of the Messina-Palermo motorway layout

2009

This paper presents the first results of the MMS (Mobile Mapping System) survey on the geometry of the A20 italian motorway Messina-Palermo. The layout parameters are the essential data for an effective management of a single or a road network. In particular these parameters are essential for applying the Design Consistency methodology to proposed or existing road infrastructures; through this methodology the road manager can make sure that the road characteristics are adjusted to the driving behaviour of motorists by analysing the relationship between horizontal and vertical alignment and the design and operating speed. Both the difficult finding of the road design schemes, particularly in…

Performance improvements of asphalt mixtures by dry addition of polymeric additives

2017

This paper shows the results of an experimental study concerning the development and optimization of asphalt mixtures for binder and base courses, improved with specifically engineered additives. The focus was on the mechanical improvements of the mixtures as achievable via dry modification with polymeric additives by making use of aggregate and bitumen of average quality, as locally available, in order to limit the consumption of virgin materials. The results allowed interesting conclusions to be drawn about the use of polymeric additives for these mixtures. In particular, the modified mixtures proved to have better performance in terms of both permanent deformation resistance and stiffnes…

CONGLOMERATI AD ALTO MODULO (EME) MIGLIORATI CON ADDITIVI PLASTICI

2014

Fatigue resistance: is it possible having a unique response?

2012

The mechanical characterisation of the asphalt concrete in terms of both the fatigue resistance and the stiffness modulus is necessary to use any design method of the flexible road pavements. Different kinds of test are usually used in experimental work such as bending tests, uniaxial tests, etc., but sometimes they do not give the same answer. In this paper mechanical characterization was carried out by means of fatigue tests undertaken with two most used testing machines for asphalt material: two point bending (2PB) test at IFSTTAR in Nantes (France) and four point bending (4PB) test at University of Palermo, in Palermo (Italy). Different strain controlled tests were undertaken for the sa…

Mechanical and environmental performance comparisons of improved asphalt pavement wearing courses with high quality aggregates, steel slags, and poly…

2023

The use of waste materials in the construction of hot mix asphalt (HMA) pavements is an important opportunity for environmental sustainability. When properly designed, the alternative mixtures may also guarantee excellent mechanical performance. In this study, the results of an experimental analysis carried out on dense-graded HMAs are presented. In particular, the performance of a "traditional" surface mixture with limestone aggregate (designed with neat bitumen or a polymer-modified bitumen within the typical acceptance requirements for intended use in wearing courses) was compared with two alternative mixtures. The research investigated a surface mixture including coarse basaltic aggrega…