Search results for "bitumi"
showing 10 items of 28 documents
New simplified approach for obtaining a reliable plateau value in fatigue analysis of bituminous materials
2017
The Plateau Value (PV) based on the Ratio of Dissipated Energy Change (RDEC) approach has been proven to provide a unique relationship with the fatigue life, N-f, independent of loading mode, temperature and frequency. In this paper, a new simplified approach is proposed to compute the unique energy parameter PV. The results of this study show that applying the proposed method allows a unique fatigue power law to be produced and eliminates the ambiguity and variability in calculating PV. However, the study also shows that the PV-N-f fatigue curves for bituminous materials are dependent on material type which is contradictory to other studies dealing with PV. The study also highlights the im…
Recommendation of RILEM TC237-SIB: protocol for characterization of recycled asphalt (RA) materials for pavement applications
2018
This recommendation proposes an experimental protocol to characterize Recycled Asphalt (RA) materials. The guidelines presented in this document are based on the results of a Round Robin Test (RRT) organized by the RILEM Technical Committee 237-SIB “Testing and characterization of sustainable innovative bituminous materials and systems” and provide information on the testing procedure, data analysis and indications for the preparation of a test report.
Bio materials with reclaimed asphalt: from lab mixes properties to non-damaged full scale monitoring and mechanical simulation
2019
Three innovative environmentally friendly pavement materials, designed with 50% of Reclaimed Asphalt and three different biomaterials (2 bio-additivated bitumens and 1 bio-binder), were produced in an industrial plant. These mixes were tested in lab and also at full scale using an Accelerated Pavement Test facility. The asphalt mix viscoelastic properties were measured in lab and their intrinsic viscoelastic response were simulated. These rheological models are used to simulate the pavement mechanical response using both elastic and viscoelastic multilayer codes. Hence, full scale measurement performed during the full scale test at an early stage (without damages) can be compared with these…
Characterization of rubberized asphalt for railway sub-ballast. Improvements in the mix-design, performance features and rational methodology of HMA_…
2018
(STR) can be incorporated into asphalt mixtures in two different methods, which are referred to as the wet-dry process. The blending of recycled rubber (CRM) with asphalt has been used for years, and several manufacturing processes have been developed in Europe as well as in the USA. The use of a bituminous sub-ballast layer has been pointed out as an exciting alternative to the granular sub-ballast design traditionally applied in most railroad tracks. Frequently, unbound granular materials are replaced by bituminous sub-ballast that provide additional benefits to the subgrade protection. Much research has been conducted on finding other alternative material to be used as a modifier in asph…
CHARACTERIZATION OF RUBBERIZED ASPHALT FOR RAILWAY SUB-BALLASTS
Tesi di dottorato sotto la supervisione del professore Gaetano di Mino del Dipartimento di Ingegneria Civile di Palermo), come borsista Marie-Curie all'interno del progetto SUPRITN 2013/2017. Il mio lavoro e la linea della ricerca riguarda i conglomerati bituminosi con granulato di gomma per lo strato di sub-ballast nelle linee ferroviarie. L’attività di ricerca comprende il mix-design dell’asfalto con aggiunta di gomma, la caratterizzazione e le prestazioni per la ferrovia in termini di comportamento meccanico e lo smorzamento delle vibrazioni. In particolare con l’avvento dell’alta velocità, diversi studi hanno evidenziato ottime caratteristiche fisico-meccaniche per ciò che riguarda il c…
Recommendation of RILEM TC237-SIB on fragmentation test for recycled asphalt
2019
This recommendation describes how to characterize the reclaimed asphalt through the fragmentation test. The guidelines given hereafter are based on the results of a round robin test organized by the RILEM Technical Committee 237-SIB ‘‘Testing and characterization of sustainable innovative bituminous materials and systems’’ and provide information on the testing procedure, data analysis and indications for the preparation of a test report.
Toward more realistic viscosity measurements of tyre rubber–bitumen blends
2014
AbstractThe measurement of rheological properties of the tyre rubber bitumen blends is often challenging due to presence of suspended tyre rubber’s crumbs. Furthermore, the phase separation during the course of measurements makes the viscosity of these non-homogeneous blends difficult to ascertain. In this study, a new dual helical impeller was designed and manufactured to be used with a rotational viscometer in order to have a real-time control of the viscosity while performing a laboratory mixing of the blends. Layer based manufacturing techniques showed to be a convenient method to produce complex shaped impeller prototypes before manufacturing the more expensive stainless steel assembly…
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…
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.