72 research outputs found

    monitoring of solid particulate airborne samples from mountain snow in some sites of the alps italy

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    In the last decades, few days a week, several city centres in Italyare closed at vehicular traffic in order to limit the presence of particulate matter, often exceeding the limits set by law [1,2]. The particulate matter have an impact on human health [3,4], in the cultural heritage and natural environment deterioration [5,6]. Many studies have been the carried out in air monitoring in urban areas while the targeted surveys to assess the impact on air quality of snow dispersion for ski activities are rare. Thanks to the Autonomous Province of Trento it has been possible to sample the snowpack in some ski areas inItalyand thanks to stratigraphic profiles it has been possible to observe variations of the chemical composition over time. Natural contribution is strictly related to winds and currents movement, for this reason a deep knowledge of these factors can help in the determination of the prevalent trajectories during the year [7,8]. During a penetrometeric and stratigraphic profile on Presena glacier, the main nivo-meteorological features, air temperature and temperature inside the different layers of the snowpack have been measured. Some snow samples has been collected and analyzed by SEM-EDS, ICP-MS and IC. These qualitative and quantitative analyses allow to obtain chemical and mineralogical composition to define the emitting source

    Recycled aggregates for concrete: production quality control

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    In this study, it is demonstrated how the traditional engineering characterisation procedures, for aggregates for concrete, mainly focus on physical-mechanical aspects, can be enhanced through a complementary study, using chemical-mineralogical techniques traditionally applied on geological materials. A chemical mineralogical assessment, involving X-ray fluorescenc and, X-ray diffraction, was used in this study in order to characterise the materials and highlight their potential in quality control procedures of recycled aggregate production. This study demonstrates that aggregate production quality control regimes can be benefited significantly by the introduction of chemical mineralogical techniques for the quality assessment and consistency during production

    Petrographic and physical-mechanical investigation of natural aggregates for concrete mixtures

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    The availability of different lithology with which concrete can be packaged could create substantial questions on the differences that they can provide to the same mixture. Different kinds of aggregates were analyzed individually to investigate their main characteristics, which allowed us to package five types of concrete mixtures. These five mixtures were compared to each other through compressive strength values. Furthermore, it was considered microscopically what possible differences could exist between these different mixtures, for example, differences in the cement/aggregate reaction. The chemical characterization of the aggregates, used as the skeleton of the cement mixes, was proposed as an important investigative phase in order to better understand the differences in the geotechnical and physical-mechanical characteristics and to verify the presence of any harmful phases for the durability of the concrete

    Chemical-mineralogical characterisation of coarse recycled concrete aggregate

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    The construction industry is now putting greater emphasis than ever before on increasing recycling and promoting more sustainable waste management practices. In keeping with this approach, many sectors of the industry have actively sought to encourage the use of recycled concrete aggregate (RCA) as an alternative to primary aggregates in concrete production. The results of a laboratory experimental programme aimed at establishing chemical and mineralogical characteristics of coarse RCA and its likely influence on concrete performance are reported in this paper. Commercially produced coarse RCA and natural aggregates (16-4 mm size fraction) were tested. Results of X-ray fluorescence (XRF) analyses showed that original source of RCA had a negligible effect on the major elements and a comparable chemical composition between recycled and natural aggregates. X-ray diffraction (XRD) analyses results indicated the presence of calcite, portlandite and minor peaks of muscovite/illite in recycled aggregates, although they were directly proportioned to their original composition. The influence of 30%, 50%, and 100% coarse RCA on the chemical composition of equal design strength concrete has been established, and its suitability for use in a concrete application has been assessed. In this work, coarse RCA was used as a direct replacement for natural gravel in concrete production. Test results indicated that up to 30% coarse RCA had no effect on the main three oxides (SiO2, Al2O3 and CaO) of concrete, but thereafter there was a marginal decrease in SiO2 and increase in Al2O3 and CaO contents with increase in RCA content in the mix, reflecting the original constituent's composition

    The Riminaldi’s Lithotheque (Ferrara): an example of stone materials’ archives in Italy.

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    An important part of the Italian cultural heritage is constituted by monuments built using natural stones. Unfortunately some of the stone resources used for building, architectural and sculptural purposes are currently exhausted and our knowledge is restricted at the materials used for them. This fact can cause problems not only during stone material research for new monuments but also considerable influences in planned restoration of monuments, originally built with stone that are not more available. The Riminaldi’s Lithotheque was donated in the 1763 at the Ferrara Borough by the nobleman prelate Gian Maria Riminaldi and currently is displayed at the Bonacossi Palace in Ferrara. The Riminaldi’s Lithotheque is unique and made with extreme care and accuracy; it well represents the double aspects pursued during the Age of Enlightenment where the erudite people were interested in sciences and antiquities. The Riminaldi’s Lithotheque well synthesize the great marble works season in Rome during the middle of the XVIII century. The Lithotheque is constituted by a small wood “consolle” with a intricate manufacturing; inside it is composed by 131 plugs of natural stones, each one classified using its Latin name. In this work each type of rock represented in the Lithotheque will be characterized using a petrographical approach. The stone materials in the Lithotheque have been then compared with the materials presented in the published stone Atlases in order to identify authentic lithologies, or stone showing similar properties. The results will be useful in the choice of better stone materials during the reconstruction of historical monument

    PROVENIENZA E CARATTERISTICHE DEI CARBONATI UTILIZZATI COME SEGNACOLI TOMBALI NELLA NECROPOLI DI SPINA

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