Дисертації з теми "Building materials – Acoustic properties"
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Niang, Ibrahim. "Contribution à la certification des bâtiments durables au Sénégal : cas d'étude des matériaux de construction biosourcés à base de Typha." Thesis, Reims, 2018. http://www.theses.fr/2018REIMS030.
Повний текст джерелаThis work is a part of PNEEB/Typha project (National Program for Energy Efficiency of Buildings) for the valorisation of an invasive reed, the Typha Australis, as a thermal insulator to improve the energy efficiency of buildings in Senegal. An agromaterial based on clay soil and Typha Australis is elaborated in order to evaluate the influence of the amount and fibres morphology on the material behaviour. For this, two production mode of granulates are chosen: longitudinal and transversal cut. Physical properties are studied (porosity, apparent, and absolute density, microstructure) and mechanical strength is determined. Sound absorption is also evaluated, as well as hygrothermal properties, and fire behaviour. Results show that granulate morphology affects the mechanical shear and flexure behaviour, as well as the acoustic absorption. Its impact on the compression strength is less pronounced. A greater portion of Typha fibers reduces the mechanical strength. However, hygrothermal performances are increased due to the aggregates porosity. Typha transverse fraction improves thermal resistance and increase water vapor transfer. This study also shows that these materials are excellent moisture regulators. Finally, fire tests reveal that it can be classified as combustible but non-flammable due to the clay presence. The fibres shape does not have a great influence
Huang, Weichun. "Acoustic properties of natural materials." Thesis, Le Mans, 2018. http://www.theses.fr/2018LEMA1031/document.
Повний текст джерелаStraw-inspired metamaterials for sound absorption are investigated in this Thesis. A straw stack is idealized as a highly concentratedresonant anisotropic porous medium constituted of a periodic arrangement of densely packed cylindrical hollow tubes. The approach tothis metamaterial relies on the two-scale asymptotic homogenization of a permeable array of perfectly rigid resonators, where the physicsis further enriched by tailoring inner resonances. The main features of such sound absorbing medium are the possibility for the effectivecompressibility to become negative around the tube resonance and the drastic reduction of the effective sound speed (slow sound) at verylow frequency in the system. Moreover, an optimal configuration for sound absorption is designed, based on the critical couplingcondition, in which the energy leakage out of the open resonant system is perfectly compensated by the intrinsic losses induced by thevisco-thermal losses both in the anisotropic matrix and in the resonators. Impedance tube measurements are performed on 3-D printedsamples with controlled parameters to validate the theoretical results. This metamaterial is a sub-wavelength absorber that can achievetotal absorption at a very low frequency and possesses a quasi-band-gap around the tube resonance. Furthermore, the anisotropic nature ofthe configuration gives rise to high absorption at low-frequency range for all incidences and diffuse field excitation. It paves the way tothe design of angular and frequency selective sound absorber. To conclude, the results of this Thesis show that straw is a good candidatefor perfect sound absorption
Sklar, Zenon. "Quantitative acoustic microscopy of coated materials." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308851.
Повний текст джерелаKrezel, Zbigniew Adam, and n/a. "Recycled aggregate concrete acoustic barrier." Swinburne University of Technology, 2006. http://adt.lib.swin.edu.au./public/adt-VSWT20060821.154340.
Повний текст джерелаKrezel, Zbigniew Adam. "Recycled aggregate concrete acoustic barrier." Australasian Digital Theses Program, 2006. http://adt.lib.swin.edu.au/public/adt-VSWT20060821.154340.
Повний текст джерелаSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Civil Engineering, Swinburne University of Technology - 2006. Typescript. Includes bibliographical references.
Sun, Ruting (Michelle). "Characterization of the acoustic properties of cementitious materials." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/27308.
Повний текст джерелаJohnson, Wayne Michael. "Structural acoustic optimization of a composite cylindrical shell." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131213/unrestricted/johnson%5Fwayne%5Fm%5F200405%5Fphd.pdf.
Повний текст джерелаLi, Qingchun. "Measurement of acoustic properties of materials using torsional waves." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/15860.
Повний текст джерелаCramer, Mark James. "Effects of materials on the acoustic properties of clarinet barrels." Thesis, The University of North Carolina at Greensboro, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3708106.
Повний текст джерелаThis project was intended to provide empirical data to determine if materials (e.g. Cocobolo, Mopane, Grenadilla, Delrin, and Purpleheart) used to make clarinet barrels have an effect on sound quality and response. The following questions were addressed in this study: For clarinet barrels, do different types of exotic hardwoods and plastics have a measurable effect on the sound qualities (timbre) of the clarinet? Do different materials used to manufacture clarinet barrels have a measurable effect on the response (immediacy of tone and vibration to the player) of the instrument? Do different materials have a measurable impact on the intensity (volume/projection) of the clarinet? Will participants have a preference for specific materials tested? Results indicated that 25% of participants chose Mopane, 25% of participants chose Grenadilla, 25% of participants chose Delrin, and 25% of participants chose Purpleheart, meaning no material was preferred by a majority of the participants. No participant chose Cocobolo. Though there were commonalities among recordings of each material, the findings were not substantial enough to determine true differences in timbre, response to articulation, or intensity.
俞佩賢 and Pui-yin Yu. "Metal alkylidyne complexes as building blocks for molecular materials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31238002.
Повний текст джерелаFu, Jin. "Development of polymeric foam materials with improved mechanical and acoustic properties." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/26905.
Повний текст джерелаCarbajo, San Martín Jesús. "Contributions to the study of the acoustic properties of porous materials." Doctoral thesis, Universidad de Alicante, 2018. http://hdl.handle.net/10045/80027.
Повний текст джерелаMeng, Han. "Acoustic properties of novel multifunctional sandwich structures and porous absorbing materials." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC008/document.
Повний текст джерелаImplementation of acoustic materials is an effective and popular noise reduction method during propagation. Acoustic properties of novel multifunctional sandwich structures and porous absorbing materials are studied in the dissertation. The main contributions of the dissertation are given as, Sandwich panels generally have excellent mechanical properties and good sound transmission loss (STL), but no sound absorption ability. Novel multifunctional sandwich structures are developed by integrating micro perforations and porous absorbing materials to the conventional structurally-efficient corrugated and honeycomb sandwich panels to achieve good SAC and STL at low frequencies. Low frequency sound absorption and sound transmission loss (STL) of corrugated sandwich panels with different perforation configurations are evaluated both numerically and experimentally. Finite element (FE) models are constructed with considerations of acousticstructure interactions and viscous and thermal energy dissipations inside the perforations. The validity of FE calculations is checked against experimental measurements with the tested samples provided by additive manufacturing. Compared with the classical corrugated sandwich panels without perforation, the perforated corrugated sandwich panels (PCSPs) with perforations in its face plate not only exhibits a higher SAC at low frequencies but also a better STL as a consequence of the enlarged SAC. The enlargement of SAC and STL should be attributed to the acoustical resonance induced by the micro perforations. It is also found that the PCSPs with perforations in both the face plates and corrugated cores have the lowest resonance frequencies of all the PCSPs. Besides, the acoustic properties of honeycomb sandwich panels with microperforated faceplate are also explored. An analytical model is presented with the assumption that displacements of the two faceplates are identical at frequencies below the faceplate resonance frequency. The analytical model is subsequently verified by finite element models and existing experimental results. Unlike classical honeycomb sandwich panels which are poor sound absorbers, perforated honeycomb sandwiches (PHSPs) lead to high SAC at low frequencies, which in turn brings about increment in the low frequency STL. Influences of core configuration are investigated by comparing PHSPs with different honeycomb core configurations. In order to enlarge the SAC bandwidth of perforated sandwich panels, porous absorbing materials are added to the cores of novel perforated sandwich panels. FE models are set up to estimate the SAC and STL of perforated sandwich panels with porous materials. Results show that perforated sandwich panels with porous material can provide SAC with broader bandwidth and lower resonance frequency than that without porous materials. Whereas the peak values in the SAC and STL curves are reduced due to the weakened acoustical resonance by the porous materials. […]
MacKenzie, Roderick. "The non-destructive evaluation of Sitka spruce mechanical properties using acoustic methods." Thesis, Edinburgh Napier University, 2009. http://researchrepository.napier.ac.uk/Output/6039.
Повний текст джерелаStahlberg, Martin. "Acoustic monitoring and control system to determine the properties of damping materials." Thesis, Nelson Mandela Metropolitan University, 2012.
Знайти повний текст джерелаVan, der Kelen Christophe. "Vibro-acoustic modelling of anisotropic poroelastic materials : characterisation of the anisotropic properties." Doctoral thesis, KTH, MWL Strukturakustik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-137809.
Повний текст джерелаQC 20131219
Mosharrof, Mohammad Sazzad. "Study and modelling of lightweight floor structure regarding its acoustic properties." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17520.
Повний текст джерелаGodkänd; 2010; 20100809 (sazmos); LICENTIATSEMINARIUM Ämnesområde: Teknisk akustik/Engineering Acoustics Examinator: Professor Anders Ågren, Luleå tekniska universitet Diskutant: Docent Jonas Brunskog, DTU, Department of Electrical Engineering, Denmark Tid: Tisdag den 7 september 2010 kl 14.00 Plats: F719 Taylor, Luleå tekniska universitet
Mahasaranon, Sararat. "Acoustic and thermal properties of recycled porous media." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5516.
Повний текст джерелаBranch, James. "Plastic properties of fresh high strength concrete." Thesis, University of Surrey, 2001. http://epubs.surrey.ac.uk/842953/.
Повний текст джерелаDoane, John William. "Measurements on the condition of compliant coatings for prediction of acoustic performance." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17588.
Повний текст джерелаVan, der Kelen Christophe. "Characterisation of anisotropic acoustic properties of porous materials - inverse estimation of static flow resistivity." Licentiate thesis, KTH, MWL Strukturakustik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-31183.
Повний текст джерелаQC 20110311
Elzokra, Ahmed Adel Emhemed. "Damage mechanisms in porous building materials due to salt crystallization: formulation of equivalent materials for masonry." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Знайти повний текст джерелаKhor, Han Chuan. "Mechanical and structural properties of interlocking assemblies." University of Western Australia. School of Civil and Resource Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0026.
Повний текст джерелаKenney, Debra M. "A short water-filled pulse tube for the measurement of the acoustic properties of materials at low frequencies." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/16671.
Повний текст джерелаHartschuh, Ryan D. "Optical Spectroscopy of Nanostructured Materials." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1195016254.
Повний текст джерелаRabell, Montiel Adela. "Development of acoustic tissue mimicking materials for preclinical ultrasound imaging applications." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31342.
Повний текст джерелаJanuševičius, Tomas. "Research on the acoustic qualities of building materials and structures and their use for noise reduction in premises." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110621_170924-08631.
Повний текст джерелаDisertacijoje nagrinėjamos statybinių medžiagų ir konstrukcijų garso izoliaci-nės savybės. Disertacijos tikslas – natūrinėmis sąlygomis ir triukšmo slopinimo kameroje ištirti ir nustatyti konstrukcijas, kurios, kaip pastatų vidinės ir išorinės sudėtinės dalys, užtikrintų vidaus patalpų apsaugą nuo triukšmo, ir tuo pagrindu sumodeliuoti konstrukcijų garso izoliavimo rodiklius. Šiame darbe sprendžiami keli pagrindiniai uždaviniai: statybinių medžiagų ir konstrukcijų akustinių savybių tyrimai triukšmo slopinimo kameroje ir natūrinė-mis sąlygomis, matavimų rezultatų palyginimas, perspektyvių konstrukcijų garso izoliavimo rodiklių įvertinimas modeliavimo būdu. Disertaciją sudaro įvadas, aštuoni skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašas. Įvadiniame skyriuje pristatoma tiriamoji problema, darbo aktualumas, apibū-dinamas tyrimų objektas, formuluojamas darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, nusakomas darbo mokslinis naujumas ir darbo rezultatų praktinė reikšmė, išvardijami ginamieji teiginiai. Įvadas baigiamas disertacijos tema auto-riaus paskelbtų publikacijų ir pranešimų konferencijose pristatymu bei disertacijos struktūra. Pirmajame skyriuje analizuojama su disertacijos tema susijusi literatūra. Sky-riaus pabaigoje formuluojamos išvados. Tyrimų metodikos pateiktos kiekvieno skyriaus pradžioje. Antrajame skyriuje išdiferencijuojami triukšmo slopinimo kameroje vykdyti tyrimai ir analizuojami jų... [toliau žr. visą tekstą]
Lisy, Frederick Joseph. "Effect of orientation on properties of reinforced polypropylene and evaluation of materials with scanning acoustic microscopy." Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1060794951.
Повний текст джерелаKhan, Amir. "Vibro-acoustic products from re-cycled raw materials using a cold extrusion process : a continuous cold extrusion process has been developed to tailor a porous structure from polymeric waste, so that the final material possesses particular vibro-acoustic properties." Thesis, University of Bradford, 2008. http://hdl.handle.net/10454/4289.
Повний текст джерелаStone, Thomas Shannon. "A numerical/experimental method for evaluating the bulk and shear complex dynamic moduli of viscoelastic polymers in the kilohertz range." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/17038.
Повний текст джерелаLi, Wanlu. "EXPERIMENTAL STUDIES ON THE DETERMINATION OF ACOUSTIC BULK MATERIAL PROPERTIES AND TRANSFER IMPEDANCE." UKnowledge, 2014. http://uknowledge.uky.edu/me_etds/48.
Повний текст джерелаMargueritat, Jeremie. "Optical and vibrational properties of new "Nano-Designed" materials produced by pulsed laser deposition." Phd thesis, Université Paul Sabatier - Toulouse III, 2008. http://tel.archives-ouvertes.fr/tel-00288338.
Повний текст джерелаAdhikary, Kamal Babu. "Development of Wood Flour-Recycled Polymer Composite Panels As Building Materials." Thesis, University of Canterbury. Chemical and Process Engineering, 2008. http://hdl.handle.net/10092/1795.
Повний текст джерелаWu, Ruimeng. "UTILIZATION OF EMPIRICAL MODELS TO DETERMINE THE BULK PROPERTIES OF COMPRESSED SOUND ABSORPTIVE MATERIALS." UKnowledge, 2017. https://uknowledge.uky.edu/me_etds/106.
Повний текст джерелаWillis, Richard Lance. "Non-invasive characterization of microvoided polymers under controlled static pressure and temperature using laser doppler vibrometry." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/17248.
Повний текст джерелаGunawidjaja, Ray. "Organic/inorganic nanostructured materials towards synergistic mechanical and optical properties /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29733.
Повний текст джерелаCommittee Chair: Tsukruk, Vladimir; Committee Member: Bucknall, David; Committee Member: Kalaitzidou, Kyriaki; Committee Member: Shofner, Meisha; Committee Member: Tannenbaum, Rina. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Biçer, Katherine K. (Katherine Kershen). "Multifaced stone and ceramic moulds from Bronze Age Anatolia : building an analytical protocol of mould properties and behavior during the process of metal casting." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33398.
Повний текст джерелаIncludes bibliographical references (leaves 91-96).
A three phase analytical protocol is developed to systematize the study of multifaceted serpentinite bronze-casting moulds from Bronze Age Anatolia (ca. 3500-1700 B.C.). These moulds represent a class of metal processing tools that reflect material properties and perhaps also social concerns in their development and use. In phase I of the protocol, standard serpentinite tiles are heated to known temperatures and the crack density and ineral changes at each temperature are determined using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) analysis. These results then serve to calibrate the cracking and mineralogical behaviors of serpentinite replica moulds used in controlled casting experiments during phase II. Metallography on several phase II cast objects provides additional information on heat flow through the stone. In phase III, the protocol is modified appropriately for the non-destructive study of four archaeological moulds using x-ray diffraction (XRD), x-ray fluorescence (XRF), and SEM. The applicability of the protocol to other stone and ceramic materials is discussed.
by Katherine K. Biçer.
S.M.
Chan, Ying Yin. "Investigate the engineering properties of Rubbersoil and its application for fill slope /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20CHANY.
Повний текст джерелаIncludes bibliographical references (leaves 241-249). Also available in electronic version. Access restricted to campus users.
Swinteck, Nichlas Z. "Phase-Space Properties of Two-Dimensional Elastic Phononic Crystals and Anharmonic Effects in Nano-Phononic Crystals." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/228156.
Повний текст джерелаThiam, Moussa. "Development and Engineering Properties of Construction Materials Made Using Melted Plastics Wastes as the Only Binding Phase." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42638.
Повний текст джерелаMuir, Dave D. "One-sided ultrasonic determination of third order elastic constants using angle-beam acoustoelasticity measurements." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29766.
Повний текст джерелаCommittee Chair: Michaels, Thomas; Committee Co-Chair: Michaels, Jennifer; Committee Member: Degertekin, Levent; Committee Member: Qu, Jianmin; Committee Member: Ruzzene, Massimo; Committee Member: Scott, Waymond. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Babendreier, Justin Eric. "Near aggregation: a time and frequency domain analysis using state trajectories and transfer function residues." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/91080.
Повний текст джерелаM.S.
Mohr, Benjamin J. "Durability of Pulp Fiber-Cement Composites." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7222.
Повний текст джерелаAhmed, Ejaz, Joachim Breternitz, Matthias Friedrich Groh, and Michael Ruck. "Ionic liquids as crystallisation media for inorganic materials." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138932.
Повний текст джерелаDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
Ahmed, Ejaz, Joachim Breternitz, Matthias Friedrich Groh, and Michael Ruck. "Ionic liquids as crystallisation media for inorganic materials." Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27794.
Повний текст джерелаDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Svoboda, Martin. "Projevy fyzikálních vlastností staviv v budovách v nízkoenergetickém a pasivním stavitelství." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372075.
Повний текст джерелаWen, Zhongmeng. "Contribution à l'étude des contraintes résiduelles sur le comportement mécanique des composites stratifiés ±θ". Thesis, Troyes, 2015. http://www.theses.fr/2015TROY0019/document.
Повний текст джерелаThis thesis work consists of two main parts: Deter-mination of residual stresses in composites laminates ±θ, introduced by the thermal cycle during the manufacturing process of laminates and Study of their influences on the mechanical behavior of these laminates. Limited by the current theory, the exper-imental determination of residual stresses in the laminates ±θ was very difficult. In this work, the incremental hole drilling method was performed for the residual stresses relaxation and then the gener-ated strains around the hole were measured with strain gages. The new approach proposed in this thesis allows associating the strains around the hole and the residual stresses in the laminates ±θ. The calibration coefficients were determined by the numerical simulation. With this approach, we found a linear relationship between the residual stresses and the fiber orientation angle θ for the composite laminates [02/θ2]s. By adapting a thermoelastic ma-terial model, the results obtained by our new ap-proach were modelized by the numerical study. Then we studied the influence of laminate thickness, curing cycle and hydrothermal ageing on the distri-bution of residual stresses. With the help of acoustic emission technique, the influences of the residual stresses on the damage and the mechanical behavior of composite laminates were studied through tensile tests. Finally, the importance of the residual stresses on the transverse failure of composite laminates was demonstrated comparing with the theoretical results
Samson, Gabriel. "Synthèse et propriétés des mousses minérales." Thesis, Rennes, INSA, 2015. http://www.theses.fr/2015ISAR0015/document.
Повний текст джерелаMineral foams are cellular materials usable as thermal insulation solution. The purpose of these PhD researches is to develop lightweight foams with good thermal and mechanical performances realized from highly concentrated mineral suspension. Surfactant addition is required for foaming. Six surfactants molecules are selected. Their abilities to reduce surface tension and to stabilize aqueous foam are evaluated. Two surfactants groups are detected based on different criteria: surface tension, CMC and aqueous foam stability. Concentrated mineral suspensions are yield stress fluids. The study of bubbles behavior in such fluids is performed with a transparent yield stress fluid, Carbopol® and an injection device with controlled pressure. Yield stress impacts bubbles creation, growth, stability and shape by changing local pressure distribution in the fluid nearby bubble. The study proposes a revised Laplace law depending on yield stress and bubble sphericity. Contact conditions between bubbles are influenced by surfactant addition allowing to control coalescence phenomena. In case of inter-bubbles membrane breakage, presence of yield stress leads to particular geometry of the coalesced bubbles. Mineral binders selected are a highly reactive anhydrous calcium sulfate, ordinary Portland and prompt cements. Mineral suspension formulations arise from expected fluidity criterion. Fresh paste is characterized by a low yield stress. Its bulk density depends on surfactant nature and content. Mineral foams are created with same composition. Two traditional foaming methods: mix-foaming and pre-foaming and an alternative one, the dissociated method are employed. Best thermo-mechanical performances are achieved with the dissociated method, a specific method of the laboratory. A surfactant group leads to lightweight foams which simultaneously fulfills both thermal and mechanical targeted objectives. For these surfactants a characteristic content is found leading to optimized mechanical performances. Visualizations performed with SEM reveal sensitive crystalline structure modifications depending on surfactant nature and content. Thinner and more homogeneous structures are associated with the best mechanical performances which demonstrates the existing link between the porous structure and mineral foams mechanical performances. To quantitatively evaluate porous structure, surface bubble-size distributions are built and then compared to volume bubble-size distributions obtained by tomography analysis. An analytic method linking 2D and 3D distributions is created based on stereology principles. A correction coefficient is proposed to take into account the analyzed representative surface. By controlling all production steps and associated physical phenomena during mineral foams production (from mineral suspension to solid foams), products satisfying all targeted objectives are realized: lightness, insulation and load-bearing ability
Angelin, Andressa Fernanda 1989. "Concreto leve estrutural : desempenhos físicos, térmicos, mecânicos e microestruturais." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267702.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia
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Resumo: A busca por materiais alternativos, de baixa massa específica, que possua redução na transferência de propagação de calor, associado à facilidade de manuseio e aplicação em concretos estruturais e estruturas de vedação, representa grande desafio na formulação e conhecimento do desempenho dos concretos leves. O concreto leve possui tecnologia pouco difundida em nível nacional e surge no cenário atual como um material inovador e alternativo ao concreto convencional. Frente ao exposto, este trabalho estudou concretos leves estruturais elaborados com duas graduações distintas de argila expandida e, com a finalidade de promover à manutenção das propriedades mecânicas, adicionou-se aditivo superplastificante e sílica ativa. Desenvolveu-se cinco traços distintos, que apresentaram reologia adequada, sem apresentar fenômenos de segregação e exsudação. Estudou-se algumas propriedades físicas, como índice e perda de consistência, absorção de água e massa específica do estado fresco e endurecido, os quais apresentaram uma média de 2000 kg/m3, classificando os concretos, de acordo com o ACI 213R-03 (2003), como leves. As principais propriedades mecânicas analisadas foram, resistência à compressão, apresentando, em média, 40 MPa, valor acima do mínimo prescrito pela ABNT NBR 6118:2007, para concretos estruturais, além da resistência à tração e módulo de elasticidade, as quais serviram como fundamentação na qualificação dos concretos leves estruturais, visando às exigências técnicas nacionais e internacionais para sua classificação e uso. Também foram realizados ensaios de condutividade térmica, por meio do método da placa quente protegida ("Hot Plate"), os quais apresentaram bons resultados, mostrando-se adequados no quesito desempenho térmico, de acordo com a revisão bibliográfica, bem como, com a norma nacional de desempenho térmico (ABNT NBR 15220:2005). Foram obtidas informações microestruturais sobre a zona de transição entre os agregados, convencionais e leves, e sua matriz de cimento. Foram realizadas comparações entre a massa específica seca e a resistência à compressão, assim como, comparações entre a massa específica seca e o módulo de elasticidade, sendo que tais resultados comprovam a possibilidade da utilização do concreto leve em elementos estruturais. Sugere-se, então, utilizar este concreto em painéis de vedação, pois associa-se a baixa massa específica, o conforto térmico e a resistência mecânica
Abstract: The search for alternative materials, low density, having reduced transfer of heat propagation, combined with ease of handling and application in structural concrete and seal structures, constituting a major challenge in the design and understanding of the performance of lightweight concrete. The lightweight concrete technology has little known at the national level and in the current scenario emerges as an innovative and alternative material to conventional concrete. Based on these, this paper studied structural lightweight concrete made with two different grades of expanded clay, and with the purpose of promoting the maintenance of the mechanical properties was added superplasticizer and silica fume. Developed five distinct traits, which showed adequate rheology, without presenting phenomena of segregation and oozing. We studied some physical properties, such as loss of consistency index, water absorption and density of fresh and hardened, which had an average 2000 kg/m3, classifying the concrete according to ACI 213R-03 (2003), as light. The main mechanical properties were analyzed, compressive strength, with an average of 40 MPa, above the minimum prescribed by ABNT NBR 6118:2007, structural concrete, beyond the tensile strength and modulus of elasticity, which served as the basis the qualification of structural lightweight concrete, aimed at national and international technical requirements for classification and use. Thermal conductivity tests were also carried out by means of the hot plate protected ("Hot Plate") method, which showed excellent results, proving to be adequate thermal performance in the category, according to the literature review, as well as with the national standard for thermal performance (ABNT NBR 15220:2005). Microstructural information on the transition zone between aggregates, conventional and light, and its cement matrix were obtained. Comparisons between dry density and compressive strength as well as comparisons between the dry density and modulus of elasticity were performed, and these results show the possibility of using lightweight concrete in structural elements. Then it is suggested to use this concrete fence panels, as is associated with low density, thermal comfort and strength
Mestrado
Tecnologia e Inovação
Mestra em Tecnologia
Peterková, Jitka. "Vývoj a výzkum environmentálně úsporných izolačních materiálů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-233791.
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