Samuele Schiavoni

A Review of Sustainable Materials for Acoustic Applications

Acoustical sustainable materials, either natural or made from recycled materials, are quite often a valid alternative to traditional synthetic materials. The production of these materials generally has a lower environmental impact than conventional ones, though a proper analysis of their sustainability, through Life Cycle Assessment procedures, has to be carried out.Airborne sound insulation of natural materials such as flax or of recycled cellulose fibres is similar to the one of rock or glass wool. Many natural materials (bamboo, kenaf, coco fibres) show good sound absorbing performances; cork or recycled rubber layers can be very effective for impact sound insulation. These materials also show good thermal insulation properties, are often light and they are not harmful for human health. Furthermore, many of these materials are currently available on the market at competitive prices.There is however a need to complete their characterization, both from an experimental and a theoretical point of view, and...

Sound absorbing properties of materials made of rubber crumbs

Recycled tyre granules can be used for manufacturing acoustic insulating and absorbing materials, with applications in buildings and road barriers. Therefore, the production of these materials is a valid alternative to the disposal into landfill or incineration of used tyres. This paper presents the results of sound absorbing coefficient measurements of several samples manufactured at the Acoustics Laboratory of the University of Perugia. The sound absorbing panels were produced by mixing rubber crumbs and an adequate binder in a proper proportion and then by compacting the obtained mix. The methodology used to evaluate coefficient of absorption coefficient is indicated in ISO 10534‐2 standard, thanks to an impedance tube. The influence on the absorption performance of granules size, binder concentration, thickness and compaction ratio of the samples was investigated and an optimization process was carried out, in order to produce a sample with satisfying acoustical performances.

A review and comparative analysis of European priority indices for noise action plans

The European Union has provided in recent years (and is going to update) several tools to harmonise noise mapping methodologies through directives and guidelines. Unfortunately the same efforts have not been put in the harmonisation of approaches for Noise Action Plans, the effective instruments to manage noise impacts. As a consequence, each European Member State at national or even at local level defined its own methodology, usually considerably different one from the others. Nevertheless, the most common approach to deal with noise impact at a policy, economic and strategy level is the use of priority indices focused to highlight areas or buildings where mitigation actions are more advisable or urgent. The aim of the present research is to provide a review of the most used European priority indices and also to test some of them in a study area. The comparative analysis demonstrates that the method chosen for the prioritisation deeply affects the ranking of the areas where noise measures need to be realized. Some methods tend to give high priority to noise sensitive locations, others to high populated buildings, and others to the areas where noise levels are high. The study proves how much common approaches are needed also for Noise Action Plans to reach a coherent noise policy within European boundaries.

Thermal and optical characterization of natural and artificial marble for roof and external floor installations

Some types of buildings need to use certain materials for aesthetic reasons, like churches or mosques. Marble is one of the most common materials usually installed on roofs and floors. The measurement of the thermal and optical characteristics can be useful to understand its behaviour when it is subjected to thermal loads such as solar radiation or high temperature winds. The paper shows a comparison study between natural and artificial types of marble, to investigate the thermal characteristics both in steady-state and transient conditions. Optical properties and surface emissivity were evaluated, in order to calculate the Solar Reflectance Index (SRI); the specific heat, the thermal conductivity and the density were measured to define the thermophysical properties useful for the dynamic analysis. Finally, a test bench was created to check the marble behaviour under known artificial irradiation.

The contribution of LIFE+ NADIA project on the implementation of the European Directive on Environmental Noise

Abstract NADIA, acronym of Noise Abatement Demonstrative and Innovative Actions and information to the public, was a European Project funded as part of the announcement Life+ 2009 between October 2010 and June 2014. Five Italian partners were involved in the project: two provinces, (Genova, the coordinating beneficiary, and Savona), two municipalities (Vicenza and Prato), and a technical coordinator (CIRIAF/University of Perugia). All the public bodies were obliged to perform the actions required by the Environmental Noise Directive, i.e., noise mappings of major roads for the provinces and of the agglomerations for the municipalities and the consequent noise action plans. The four public bodies, with the support of the research centre, decided to go beyond the mandatory requirements of END in order to achieve the following main objectives: (i) to improve the methodologies for the realization of noisemappings and action plans, with a particular focus on road traffic noise; (ii) to increase the awareness of citizens and of potential stakeholders by focused communication and dissemination activities; (iii) to assess the technical and economic feasibility of best practices in tackling road traffic noise. The paper reports a summary of the activities performed by the partners during the project.

The Noise Abatement Plan of an Italian Road Network: A Comparison Between Standard and Innovative Methodologies

The Italian legislation prescribes that the managing authorities of transportation infrastructures have to prepare a noise control and abatement plan, using established procedures and indexes defined both at national and regional level. The aim of the paper is to compare the standard procedure given by Umbria Region with three innovative methodologies proposed by the authors to increase the adequacy and the quality of roads noise planning activity. Both standard and innovative approaches require the creation of a ranking of priority to define where noise abatement actions are most necessary. The proposed methodologies introduce at various levels a more detailed phase of noise mapping, by using facade noise map instead of grid noise map, and define new rankings of priority based on improved location of calculation points. More accurate and realistic noise plans allow to optimize the budget allocated for acoustic rehabilitation and to mitigate the most critical situations. The innovative procedures can be easily transferred at European level for the realization of Noise Action Plans requested by the Environmental Noise Directive 2002/49/EC.

Assessment of the Performance of Road Markings in Urban Areas: The Outcomes of the CIVITAS RENAISSANCE Project

In the framework of the EU funded CIVITAS plus RENAISSANCE project, a research activity was focused on the definition of a new methodology for evaluating the global quality of the road markings at urban level, both from a technical and an economic point of view, in order to assure road safety. Two innovative indicators were developed: one for the assessment of the technical performance (CIS-Q) and one for the optimization of the budget (CIS-C). In order to rate the global quality of municipal road markings, the performance indicator CIS-Q takes into account all the parameters characterizing the performance of road markings, such as luminance coefficient in day conditions Qd, retroreflectivity in night conditions RL (dry, wet), skid resistance SRT, colour, kind of material and ageing of the pavement markings, traffic volumes, characteristics of road surface and average local weather conditions. The economic indicator CIS-C considers the budget available for the road manager and compares it with the one needed to ensure an adequate level of quality for road markings.