Search results for "Strade"

Le procedure di audit della sicurezza sul progetto e sulle infrastrutture in esercizio

2010

Approccio teorico-sperimentale per l'analisi delle condizioni operative di rotatorie urbane non convenzionali

2008

I metodi tradizionali di analisi delle rotatorie cadono in difetto in presenza di schemi organizzativi dell’intersezione, nei quali l’organizzazione geometrica, unitamente alla molteplicità delle situazioni di traffico ed all’inserimento in contesti vincolati, induce comportamenti di guida anche molto distanti da quelli osservabili in rotatorie convenzionali. Quanto evidenziato interessa, in particolare, l’ambito urbano, dove le intersezioni a circolazione rotatoria risultano particolarmente diffuse e si caratterizzano per requisiti geometrico-funzionali spesso distanti da quelli propri delle rotatorie convenzionali. Uno dei maggiori ostacoli che si incontrano nell’analisi delle condizioni …

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…

Managing Greenhouse Gas Emissions for Airport Inventories: An Overview

2011

For some years now, problems relating to gas emissions that affect climate and result from human activities have assumed a global dimension of large importance. The climate is, indeed, influenced by the concentrations of some pollutants in the atmosphere; these pollutants trap the long wave radiation emitted by the Earth and alter the energy balance, causing an accentuation of the natural greenhouse effect. In this view an inventory of greenhouse gases can become the benchmark against which to measure the achievement of quantitative targets set at the political level in the fight against climate change. Contrary to a general inventory of emissions related with air quality objectives and loc…

Improving the rheometry of rubberized bitumen: experimental and computation fluid dynamics studies

2017

Abstract Multi-phase materials are common in several fields of engineering and rheological measurements are intensively adopted for their development and quality control. Unfortunately, due to the complexity of these materials, accurate measurements can be challenging. This is the case of bitumen-rubber blends used in civil engineering as binders for several applications such as asphalt concrete for road pavements but recently also for roofing membranes. These materials can be considered as heterogeneous blends of fluid and particles with different densities. Due to this nature the two components tends to separate and this phenomenon can be enhanced with inappropriate design and mixing. Thi…

Road design problems solved by affine arithmetic

2015

In this paper we propose the use of techniques based on range numbers for solving problems of road designing. We applied the Affine Arithmetic to verify the driver's visibility in a horizontal curve, providing very interesting results and confirming its usefulness even in the most complex analytical expressions. The preparation of charts such as those proposed in this paper also makes this method directly accessible to those not so familiar with this technique.

Integrating Circularity in the Sustainability Assessment of Asphalt Mixtures

2020

Rising concerns about the impacts that the road engineering industry is imposing to the environment have redirected national road authorities to firmly re-consider the sustainability implications of their operations. Lately, though, sustainability has established a forceful correlation with the Circular Economy and its principles. The road engineering industry, therefore, is moving towards more circular approaches. However, this is occurring without the assessment of the potential impacts of such a transition. For this reason, in this study, a composite indicator, namely, Environmental Sustainability and Circularity indicator (ESCi), for investigating the potential effects that increased ci…

A methodology to identify critical road sections by means of cyclist's fatigue

2020

This paper proposes a procedure for determining cyclists’ fatigue state along a specific road, as a function of some external variables related to the environmental context. When the physical fatigue reaches extreme levels, the cyclist’s ability to deal with an unexpected event or with an emergency condition is particularly limited; further, poor road pavement conditions may increase occurrence probability of critical events. In order to identify the potentially most dangerous road paths, the authors defined a methodology to build a model for cyclist’s fatigue evaluation in terms of Heart Rate class. The proposed procedure is based on the collection of simple data processed by means of Patt…

Environmental Performance Evaluation at Urban Roundabouts

2021

Transformation toward greener, healthier and safer management of urban mobility demand is needed soon. Smart tools are available to assess the impact of new infrastructural projects and road facilities also from an environmental point of view. In this pilot study pollutant emissions at a sample of urban roundabouts were estimated employing the Vehicle Specific Power methodology which needs second-by-second speed profiles both gathered in the field and simulated in AIMSUN. The versatility of the micro-simulation model for a calibration aimed at improving accuracy of the emissions estimates was tested in order to ensure that second-by-second trajectories experienced in the field properly refl…

Environmental Performance Assessment of Urban Roundabouts

2021

To meet continuous and sustainable improvement on road infrastrucutures, new technologies and smart devices are encouraging the development of a mobile crowdsensing system for collecting and monitoring data to be used in efficiency assessment. In this view, the paper proposes a methodological approach that employs in an integrated way vehicle trajectory data collected in the field, the Vehicle Specific Power methodology and a microscopic traffic simulation model for estimating emissions at urban roundabouts. For a first characterization of the emissive phenomenon reference was made to an existing two-lane roundabout in Palermo, Italy, where vehicle trajectory data were collected using a sma…