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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Quartzene i betong : Hur påverkas hållfastheten?

Öhrn, Tobias January 2012 (has links)
Detta examensarbete undersöker hur Quartzene® som tillsatsmaterial påverkar hållfastheten hos betong. Arbetet sker i samarbete med företaget Svenska Aerogel AB som också äger patent på Quartzene®. Ämnet har vissa likheter med andra tillsatsmaterial som används i Sverige. Quartzene® har dock ett kartlagt innehåll vilket är en fördel jämfört med de andra tillsatsmaterialen som måste analyseras innan användning. Syftet är att prova hur Quartzene® i olika doser och diverse sammansättningar påverkar hållfastheten hos betong. Litteraturstudier har legat till grund för de praktiska provningarna och analyserna av givna resultat. Arbetet gjordes i ett byggtekniskt laboratorium med utrustning för böjdrag- och tryckhållfasthetstester, våg, elektriskt skjutmått mm. Prover gjordes på 7 och 28 dygn gamla betongprismor. Resultatet som presenteras och analyseras i rapporten visar på att Quartzene® förändrar hållfastheten. Att byta ut en del av cementen mot Quartzene® har ingen positiv inverkan på varken 7 dygn eller 28 dygnshållfastheten. Oklart hur det skulle se ut efter längre tid t ex ett år. Quartzene® blandades i som pasta i vissa betongrecept och som pulver i andra. Konsistensen på betongen blev torrare när Quartzene®pasta blandades i. Trots att pastan innehåller 85 % vatten blev alltså blandningen fast. Den blev dessutom än mer fast efter bara några minuter eftersom pastan stelnar av sig själv. Vattnet i pastan tycktes inte vilja bidra med lägre viskositet. När Quartzene® i pulverform blandades i, blev betongmassan däremot mycket lätt att arbeta med. Det går att dra slutsatser att Quartzene® i pulverform är bättre för hållfastheten än vad Quartzene®pasta är. Den ger ungefär 5 MPa högre tryckhållfasthet. Om 5 MPa skulle adderas till resultaten för betongen som blandades med Quartzene®pasta skulle den ge högre hållfasthet än den som betong var utan Quartzene®. I de recepten med mycket Quartzene® var det en mer positiv utveckling mellan 7 och 28 dygn. Därför hade varit mycket intressant att se hur det skulle ha sett ut efter 90 och 365 dagar.
2

Fuktegenskaper hos Quartzene impregnerat med salter

Buske, Elias January 2012 (has links)
Svenska Aerogel AB has developed the material Quartzene® which is of the typeprecipitated silica and contains calcium - magnesium silicate ((Ca, Mg) SiO3). Thematerial is used for molecular filtration of contaminated air. Qartzene™, which is inpellet form, is porous and has a high internal surface which is a requirement for themolecular filtration. With the use of various impregnations, filtration can affect thedesired outcome. As an example Quartzene® can be impregnated with Potassiumhydroxide and clear the air of Sulfur dioxide, SO2 (Svenska Aerogel AB, n.d).Svenska Aerogel AB has developed Quartzene® further and new areas of application hasarosee, one of these areas is how the material function within dehumidification. Thepurpose of this study is to research and analyze how different impregnation salts effecthow Quartzene® function in terms of moisture absorption and moisture desorption.Quartzene® is a hygroscopic material, which is a material that easily absorbs and exudatesmoisture from the air. Materials with high porosity absorb moisture by adsorption andcapillary condensation. A hygroscopic material strives for equilibrium with ambientenvironment which is illustrated in a sorption curve where moisture absorption is set inrelation to relative humidity. In this study the jar method is used to measure moistureabsorption, this is shown with the use of sorption curves. The jar method uses saturatesalt solutions to create environments whit a set relative humidity. Quartzene® – pellets areplaced in jars and weighed at regular intervals to determine the moisture absorption.The results of this study indicate that impregnations affect the way that Quartzene®function in terms of moisture absorption and moisture desorption. Some of theimpregnations affect the material to absorb more moisture than Quartzene® that has notbeen impregnated, while others affect the material to absorb less moisture. The resultsalso show that sodium – based impregnation gives similar results as Quartzene® that hasnot been impregnated.
3

En ekonomisk analys av att använda en Quartzenebaserad puts vid energieffektivisering av äldre q-märkta byggnader.

Fredriksson, Anton, Fors Edman, Christoffer January 2017 (has links)
Older q-labeled buildings may not be changed according to the corruptions banning, resulting in difficulties in energy efficiency of q-marked buildings, as traditional energy efficiency methods cannot be used without altering the building's properties. This report examines the profitability to energy-efficient a q-labeled building with a heat insulating plaster based on Z1 quartzene and lime cement render. By only changing the render properties of the plot, the building does not change characteristic or cultural historical value. The report sets out a general framework describing the maximum additional cost of a heat insulation plaster in comparison to a traditional plaster at four different thermal conversion coefficients; 0.2, 0.4, 0.6 and 0.8 W/m2 ×K. The framework can be used as a template that shows what a heat insulation plaster at varying thermal conductivities maximally may cost for the product to be economically viable compared to lime cement plaster.  A life cycle cost analysis is used in a case study to assess if it is profitable to energy-efficient a qlabeled building in Gävle, with a heat insulating plaster based on Z1 and lime cement pits. Five theoretical mixtures with different proportions of Z1 and lime cement plaster was analyzed to assess profitability at different thermal conductivity. The result of the case study shows that all heat-insulating plasters is economically profitable, where the most profitable mixing is the one with the highest proportion of Z1 (80%). That the most profitable mixture is the one with the highest proportion of Z1 can be explained by the fact that energy saving is increasing at a faster rate than the additional cost of the heat insulating plaster The estimated additional cost of the case study is tested in the cost ceiling to identify the profitability at different heat transfer coefficient. The results shows that walls with an high heat transfer coefficient has the largest profitability, while the walls with a lower heat transfer coefficient (a better heat transfer coefficient) is the least profitable. This is because of the walls with a higher heat transfer coefficient has a greater energy saving potential then walls whit a lower heat transfer coefficient / Äldre q-märkta byggnader får enligt förvanskningsförbudet inte förändras, vilket resulterar i svårigheter att energieffektivisera q-märkt byggnader, eftersom traditionella energieffektiviseringsmetoder inte kan användas utan att förändra byggnadens egenskaper. I denna rapport undersöks lönsamheten att energieffektivisera en q-märkt byggnad med en värmeisolerande puts baserad på Quartzene av typen Z1 och kalkcementputs. Genom att endast förändra putsens termiska egenskaper förändras inte byggnaden karaktärsdrag eller kulturhistoriska värde. I rapporten fastställs ett generellt ramverk som beskriver den maximala merkostnaden för en värmeisolerande puts i jämförelse med en traditionell puts vid fyra olika värmegenomgångskoefficienter; 0,2, 0,4, 0,6 och 0,8 W/m2×K. Ramverket kan användas som en mall som visar vad en värmeisolerande puts vid varierande värmekonduktiviteter maximalt får kosta för att produkten ska vara ekonomisk lönsam i jämförelse med kalkcementputs. I en fallstudie används en livscykelkostnadsanalys (LCC) för att bedöma om det är lönsamt att energieffektivisera en q-märkt byggnad beläggen i Gävle med en värmeisolerande puts, baserat på Z1 och kalkcementputs. Fem modellerade blandningar med olika andelar Z1 och kalkcementputs analyseras för att bedöma lönsamheten vid olika värmekonduktivitet. Fallstudiens resultat visar att samtliga värmeisolerande puts är ekonomiskt lönsamma, där den mest lönsamma värmeisolerande putsen är den med högsta andel Z1 (80%). Att den mest lönsamma blandningen är den med högst andel Z1 kan förklaras av att energibesparingen ökar i snabbare takt än merkostnaden för den värmeisolerande putsen. Fallstudiens beräknade merkostnad prövas i kostnadstaket för att identifiera lönsamheten vid olika värmegenomgångskoefficienter. Resultatet visar att väggar med en sämre värmegenomgångskoefficient (ett högt U-värde) har störst lönsamhet medan väggar med en bättre värmegenomgångskoefficient (ett lågt U-värde) har minst lönsamhet. Detta beror på att väggar med en sämre värmegenomgångskoefficient har större energibesparingspotential än byggnader med en god värmegenomgångskoefficient.
4

Mechanical properties dependence on microstructure in aerogel-like Quartzene® / Mekaniska egenskapers beroende av mikrostrukturen i aerogel-liknande Quartzene®

Ekström, Alexander, Gustafsson, Olof, Kvarned, Anders, Löf-Nilsson, Elinor, Proper, Sebastian, Sköld, Markus, Snögren, Pär, Ullsten, Oscar January 2014 (has links)
In this project the relation between pore size/porosity and the mechanical properties has been studied in the aerogel-like material Quartzene®. Quartzene® is a patented material produced by Svenska Aerogel AB. Density measurements were made on three different types of Svenska Aerogels ABs Quartzene® in the shape of pellets.These three types of Quartzene® is called CMS, ND and E9. The mechanical properties were studied by doing diametrical crush-tests on the pellets. Afterwards the samples were examined through SEM in order to study the structural properties like porosity and microstructure. By examining the materials in this order the group hoped to find a correlation between the mechanical properties and the pore size/porosity. Other microscopic analyses such as TEM and FIB was considered, but due to time limitation these methods were not used. Rough density measurements resulted in an estimated density of 0.82-0.88 g/cm3 for CMS, 0.28-0.30 g/cm3 for E9 and 0.21-0.22 g/cm3 for ND. The crush-tests resulted in a mean fracture stress of 0.81-0.89 MPa for CMS, 0.30 MPa for E9 and 0.20-0.21 MPa for ND. Studying the materials in SEM resulted in an observed mean pore size of 59-73 nm for CMS, 264-362 nm for E9 and 690-710 nm for ND in the mesoporous domain. A subtle relationship between density/pore size and fracture was obtained, with a higher density and smaller pores leading to a higher fracture stress. Due to the lack of data in this study, it is recommended though that this is something that should be examined further before any conclusions can be made. In general Quartzene® has shown to be a brittle material, but this study indicates that the mechanical properties could be controlled in somehow through the microstructure of the material, focusing on controlling the pore sizes. Further investigations in sintering of Quartzene® are also recommended in this study because of its promising effects on the mechanical properties shown in other studies.
5

The thermal insulating effects of Quartzene® on painting systems

Zendehrokh, Arwin, Mariscal, Luis, Hunhammar, Martin, Yussuf Hassan, Ismail, Pettersson, Albert January 2020 (has links)
The European Green Deal 2020 goals for reducing emissions are enforcing rules on the energy performance of buildings. Therefore thermally insulating materials used as coatings are researched to reduce the energy emissions of buildings. An essential field of interest are nanomaterials. Traditional aerogel is a nanomaterial used for insulating applications due to its high porosity and large surface area, resulting in a longer path for heat to travel. However the cost and manufacturing process are highly energy demanding. Svenska Aerogel AB produces Quartzene® (Qz), a silica-based nanomaterial with similar properties as traditional aerogel. Qz can be incorporated into different paint systems to improve their thermal insulating properties. The aim of this project was to investigate the thermal insulating effects of Qz on three different painting systems (A, B, and C). Samples were moulded and their thermal properties were measured with TPS (Transient Plane Source). The thermal conductivity decreased as the wt% of Qz increased, up until around 10 wt% for system C. It became apparent that at higher wt%, it became harder to properly mix the samples into a good dispersion. The thermal conductivity started to increase above 10 wt%. Experiments showed that bigger particles were easier to mix into the paint than smaller.
6

Quartzene – A promising thermal insulator : Studies of thermal conductivity’s dependence of density and compression of Quartzene® in the form of powder.

Bamford, Erik, Ek, Gustav, Hedbom, Daniel, Nyman, Johan, Petterson, Victor, Sjöberg, Josefin, Styffe, Ida, Vizuete, Olivier January 2014 (has links)
The purpose of this project was to study Svenska Aerogel AB’s product Quartzene®, and develop its capacity as a thermal insulator. Quartzene® is a silica based mesoporous material developed by Svenska Aerogel AB, with properties similar to aerogels produced by the sol-gel process. In this report, the correlation between pore structure and thermal conductivity in the material has been studied using techniques, such as scanning electron microscopy, focused ion beam, finite element simulations and transient plane source. Its properties are interesting because of the expanding market of insulated vacuum panels; in which Svenska Aerogel AB wish to expand to. It was found that the pore sizes of M21-BU increased after compression, and the pore sizes of M4-0-2 decreased. The pore sizes of M21-BU became so large that the Knudsen effect is no longer of interest, and that could explain the different behaviors in thermal conductivity.

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