Search results for "construction materials"
showing 10 items of 21 documents
Gamma activity and geochemical features of building materials: estimation of gamma dose rate and indoor radon levels in Sicily.
2001
A high-purity germanium detector has been used to measure the abundance of radium (Ra), thorium (Th) and potassium (K) in building materials used in Sicilian dwellings. The measurements were performed to evaluate which material was suitable for the construction of an enclosure, which would have a low background emission. The materials examined in this work showed concentrations of 226Ra, 232Th and 40K dramatically variable depending on the lithologies, particularly in the case of blocks, sands and aggregates commonly used in building materials in Sicily. The results are discussed and a criterion is indicated to reduce the radiation dose to humans. Since radon inlet is a major health problem…
Timber framed with masonry infill: a historical anti-seismic device. The Portuguese Pombaline gaiola.
2017
La ricostruzione postsismica e la prevenzione sismica sono stati da sempre un fondamento costruttivo.Questo studio analizza la tipologia costruttiva della gaiola pombalina, un sitema costruttivo e strutturale molto diffuso in Portogallo ma non solo, adottato a Lisbona a seguito del terremoto del 1755. Si analizzano i materiali e le tecniche costruttive, gli elementi utili al rinforzo e consolidamento della struttura muraria, ampiamente diffuso in area mediterranea a partire dal XVIII secolo.Questo sistema costruttivo può e deve anche oggi essere considerato un utile presidio antisismico da riconoscere e preservare da interventi incolti, se non addirittura da incongrue demolizioni. Post-seis…
Numerical vibroacoustic analysis of plates with constrained-layer damping patches
2011
International audience; A numerical vibroacoustic model that can manage multilayered plates locally covered with damping patches is presented. All the layers can have an on-axis orthotropic viscoelastic behavior. Continuity of displacements and transverse shear stresses at each interface is enforced, which permits to write the entire displacement field in function of the displacements of the-common-first layer, leading to a two-dimensional plate model. The problem is then discretized by Rayleigh-Ritz's method using a trigonometric basis that includes both sine and cosine functions in order to treat various boundary conditions. The excitation can be of mechanical kind (concentrated or distri…
Tracing anthropogenic thallium in soil using stable isotope compositions.
2014
Thallium stable isotope data are used in this study, for the first time, to apportion Tl contamination in soils. In the late 1970s, a cement plant near Lengerich, Germany, emitted cement kiln dust (CKD) with high Tl contents, due to cocombustion of Tl-enriched pyrite roasting waste. Locally contaminated soil profiles were obtained down to 1 m depth and the samples are in accord with a binary mixing relationship in a diagram of Tl isotope compositions (expressed as e(205)Tl, the deviation of the (205)Tl/(203)Tl ratio of a sample from the NIST SRM 997 Tl isotope standard in parts per 10(4)) versus 1/[Tl]. The inferred mixing endmembers are the geogenic background, as defined by isotopically l…
Compatible rehabilitation of the Sicilian rural architecture: the case study of "Calcibaida" in Caltavuturo
2020
The Sicilian common typological form of rural estate is the masseria, typical of the latifundium. More particularly, it is a large fortified farm built to control and manage a vast land-property, the old fiefdoms. This paper will analyse the masseria Calcibaida as an eminent example of the mentioned Sicilian rural world. Calcibaida is located in the territory of Caltavuturo, in the centre of Sicily, within the mountain landscape of the Madonie mountains. The complex consists of a compact aggregate of buildings with an internal courtyard and a close large warehouse, further embellished by a fine drinking trough. The typological characteristics, materials and construction technologies of the …
COSTRUIRE L’AZZARDO. IL CORNICIONE NELL’ARCHITETTURA STORICA, FRA REGOLA E SPERIMENTAZIONE
2018
The book explores the historical and constructive aspects of the cornices that, from elements of protection, they can also become elements of degradation and instability due to their form. The structure of the text of this volume consists of three main parts, presenting some technical aspects and issues of uncommon attention. The first part analyzes a discussion about the formal and material values of the cornice; in fact, it presents complex characters and summarizes the problems deriving from formal and constructive requirements of the building envelope, due to the double value of ornamentation (crowning of the building) and functional component (removal system of meteoric water from the …
Sapropeļa kūdras, sapropeļa kokskaidu siltumizolācijas plāksnes un to īpašības
2014
Siltumizolācijas materiāli, kuros par pildvielu tiktu izmantoti vietējie biomasas produkti, bet par saistvielu kalpotu dabiskas izcelsmes saistvielas, piemēram, sapropelis, uzskatāmi par inovatīviem un to pielietošana sekmētu ekoloģiskās būvniecības nozares attīstību. Šādu risinājumu izstrāde ir aktuāla, jo Latvijā ir ievērojami sapropeļa resursi, kuru izmantošanu kavē to nepietiekama izpēte un ekoloģiskās būvniecības nozares intensīva attīstība. Pētījuma mērķis ir iegūt sapropeļa-koksnes, kūdras-koksnes siltumizolācijas plāksnes, noteikt optimālās plātnes sastāva attiecības un raksturot iegūto plātņu īpašības. Veikto pētījumu rezultātā tika noteiktas siltumizolācijas materiālu paraugu mehā…
Cool barnacles: Do common biogenic structures enhance or retard rates of deterioration of intertidal rocks and concrete?
2017
Sedentary and mobile organisms grow profusely on hard substrates within the coastal zone and contribute to the deterioration of coastal engineering structures and the geomorphic evolution of rocky shores by both enhancing and retarding weathering and erosion. There is a lack of quantitative evidence for the direction and magnitude of these effects. This study assesses the influence of globally-abundant intertidal organisms, barnacles, by measuring the response of limestone, granite and marine-grade concrete colonised with varying percentage covers of Chthamalus spp. under simulated, temperate intertidal conditions. Temperature regimes at 5 and 10 mm below the surface of each material demons…
How building an underwater pipeline connecting Libya to Sicilian coast is affecting environment: polycyclic aromatic hydrocarbons (PAHs) in sediments…
2009
The purpose of this study was to determine the variation of concentrations and distribution of PAHs in the sediments of the Gela coastal area (Italy) caused by the construction of an underwater pipeline connecting Libya to Sicilian coast. The receiving terminal of offshore pipeline, crossing the Mediterranean Sea, 516 Km long, up to 1127 meters deep, is located in Gela (Sicily, Italy). No bibliographic data regarding hydrocarbons are available for this area. In this paper we report the results of analysis on the water and organic along PAHs.The total concentrations of 16 PAHs in the sediments, analyzed during five surveys, ranged from 2.4 to 434 microg/kg of dry weight. The highest concentr…
Assessment of polycyclic aromatic hydrocarbons (PAHs) in soil of a Natural Reserve (Isola delle Femmine) (Italy) located in front of a plant for the …
2009
Isola delle Femmine Natural Reserve is a very little isle about 15 km from the centre of Palermo, in front of a plant for the production of cement and about 600 m from coast. In the present research, profiles soil PAHs were obtained for 16 sites within the reserve and for 8 stations on the rural soil taken as reference. summation Sigma PAHs, in the soil of investigated area, ranged from 35 to 545 microg/kg. With the aim to find the origin of PAHs in the soil of Isola delle Femmine, we compare the distribution of single analytes in the investigated area with those of the reference rural area (Monte Raffo Rosso), with those of atmospheric urban particulate collected at Palermo along with repo…