Search results for " Ferro"
showing 10 items of 499 documents
Lungo il margine, progetto adiacente alla stazione Notarbartolo a Palermo
2008
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…
The effects of laboratory ageing on rheological and fracture characteristics of different rubberised bitumens
2018
Ageing of bituminous materials can result in loss of the durability of a flexible pavement. Using rubberised bitumens can enhance pavement performance while at the same time it solves a serious waste disposal problem. Combining Warm Mix Asphalt (WMA) additives with rubberised bitumens reduces the difficulties associated with the production of asphalt mixtures using this modified binder. This work was conducted to study the effect of ageing using fundamental parameters based on performance, i.e., CTOD and Glover-Rowe parameters have been related to pavement cracking. Different unmodified bitumens and rubberised bitumens were short-term aged using the Thin Film Oven Test (TFOT) and long- term…
Fatigue and Healing Properties of Low Environmental Impact Rubberized Bitumen for Asphalt Pavement
2017
The addition of recycled tyre rubber as a modifier to enhance the mechanical properties of bitumen has proven to provide asphalt mixtures with better mechanical performance. However the rubberised bitumen presents the limitation of requiring higher manufacturing and compaction temperatures. This could be solved by subjecting the tyre rubber to sort of pre-treatments such as: Adding warm-mix additives and/or using partial devulcanisation. These solutions have the potential of lowering the overall environmental impact of the asphalt pavement, however it is still not clear whether these can be detrimental for the rubberized asphalt binder mechanical properties. This paper investigates the effe…
Thermo-rheological analysis of WMA-additive modified binders
2020
AbstractThermo-rheological characteristics of unmodified and modified bitumen have significant impacts on the mechanical response of asphalt. This study investigates the impacts of an organic and a chemical Warm Mix Asphalt additive on bitumen thermo-rheological and mechanical characteristics. Modified binders with different concentrations of each additive were studied and analysed comparatively to a 40/60 penetration grade bitumen. Frequency sweep tests were performed at different ageing levels to characterise the Linear Viscoelastic properties. The multiple stress creep and recovery, linear amplitude sweep (LAS) and low temperature creep stiffness tests, together with the Glover–Rowe (G–R…
Influence of cation order on the dielectric properties of (1 – x)Pb(Sc 0:5 Nb 0:5 )O 3 -xPb(Yb 0:5 Nb 0:5 )O 3 ceramics
2020
Ceramic lead niobates and their solid solutions (1 - x)Pb(Sc0:5Nb0:5)O3 - xPb(Yb0:5Nb0:5)O3 were synthesized by solid state reactions from oxides. The structure of investigated samples was characterized by X-ray diffraction (XRD). Dielectric studies of the ceramics were performed by means of broadband dielectric spectroscopy at the temperature ranging from 600 K to 140 K. For all ceramic samples a diffuse phase transition as well as relaxor ferroelectric behavior were observed. © 2020 Barbara Garbarz-Glos et al., published by Sciendo 2020. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Linear viscoelastic properties of high reclaimed asphalt content mixes with biobinders
2017
The use of high Reclaimed Asphalt (RA) content mixtures together with binders produced from renewable resources (biobinders) is one of the current challenges in pavement engineering research. On the one hand, RA has been used for decades, but there are still some concerns about its performance, especially when high contents are used (>30%). On the other hand, biobinders are relatively new materials, which have to be deeply characterised and studied in order to develop good practices for their use. In this paper, linear viscoelastic properties of biobinders and bio-mixtures manufactured with high RA content and biobinders are analysed and discussed. High-modulus mixtures with 50% RA were…
Strain-controlled domain wall injection into nanowires for sensor applications
2021
We investigate experimentally the effects of externally applied strain on the injection of 180$^\circ$ domain walls (DW) from a nucleation pad into magnetic nanowires, as typically used for DW-based sensors. In our study the strain, generated by substrate bending, induces in the material a uniaxial anisotropy due to magnetoelastic coupling. To compare the strain effects, $Co_{40}Fe_{40}B_{20}$, $Ni$ and $Ni_{82}Fe_{18}$ samples with in-plane magnetization and different magnetoelastic coupling are deposited. In these samples, we measure the magnetic field required for the injection of a DW, by imaging differential contrast in a magneto-optical Kerr microscope. We find that strain increases t…
Relaxor ferroelectric ceramics of LiTaO3-type
1992
Abstract A ferroelectric relaxation has been identified in Li1-xCax (Ta1-xZrx)O3(x = 0.15 and 0.20) ceramics with LiTaO3-type structure. The relaxation frequency fr is minimum and the dispersion step (ϵ′S - ϵ′∞) is maximum at TC. When x increases, a higher conductivity associated with a lower activation energy and a decrease of the magnitude of fr at Tc are observed, while the unit cell volume becomes larger, TC lower and the transition more diffuse.