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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

EN TOTALKOSTNADSJÄMFÖRELSE MELLAN CELL-, SKUM- OCH LECA-BETONG

Hansson, Mattias, Åslew Andersson, Christian January 2010 (has links)
This report provides a comparison between the products cellular concrete, foam concrete and LECA concrete. The questions to be answered during the work is how the cellular concrete stands up in cost terms to the existing competitors on the market, how the concrete products differ in design work, and in which situations the concrete varieties are preferred to use. Cellular concrete is a variant of ordinary concrete, with the difference that the ballast is exchanged from stone materials to expanded polystyrene beads (EPS). This substitution gives a product with higher insulation values but lower weight than ordinary concrete. The work was carried out by designing a survey which was sent to two hundred randomly chosen companies across Sweden, to see the building industry’s opinion of the product cellular concrete. The survey showed that cellular concrete was equals its competitors in terms of price, while the product was said to be more flexible, quicker and easier to cast. Then some of the companies, who participated in the survey, were interviewed to see more carefully, how the price, the workmanship and the time for casting and dehydration differed between the products. Meanwhile, technical data were presented for the products which formed the basis for the U-value calculation and the weight analysis. The result of this work was that LECA concrete is the cheapest option, when the Uvalue is 0,40 W/(mK) and when the total thickness, including the following works, is 200 mm. Cellular concrete was found to be cheaper than foam concrete in small quantities, in the both cases, since the foam concrete must be cast in multiple layers. In addition, foam concrete requires more equipment, which results in a higher fixed cost. Foam concrete becomes, however, more profitable the larger volumes that are cast, because the fixed charges of the product are earned by the low volume cost. Cellular concrete is suitable for smaller works, especially in tight spaces where some insulation is required. Larger volumes are not beneficial because of the high volume cost. Often, the weight may be decisive in the method and material selection. On these occasions, the cellular concrete advantages through both low weight per unit volume and good thermal insulation. To screed the cellular concrete has been shown to cause large additional costs. At times, when no need to screed the concrete surface has occurred, the total cost of the product almost halved. Cellular concrete should not be cast in layers thinner than 50 mm. LECA concrete must be cast in a layer of at least 100 – 120 mm that sufficient adhesion can be obtained. This makes the product unsuitable for small castings, including castings of the existing joists below 100 mm, but works well as foundations. Of those described options, foam concrete is most suitable in larger castings. However, it appears that the main use of foam concrete has been shown to be as a filling material in road embankments.
2

EN TOTALKOSTNADSJÄMFÖRELSE MELLAN CELL-, SKUM- OCH LECA-BETONG

Hansson, Mattias, Åslew Andersson, Christian January 2010 (has links)
<p>This report provides a comparison between the products cellular concrete, foam</p><p>concrete and LECA concrete. The questions to be answered during the work is how</p><p>the cellular concrete stands up in cost terms to the existing competitors on the market,</p><p>how the concrete products differ in design work, and in which situations the concrete</p><p>varieties are preferred to use.</p><p>Cellular concrete is a variant of ordinary concrete, with the difference that the ballast</p><p>is exchanged from stone materials to expanded polystyrene beads (EPS). This</p><p>substitution gives a product with higher insulation values but lower weight than</p><p>ordinary concrete.</p><p>The work was carried out by designing a survey which was sent to two hundred</p><p>randomly chosen companies across Sweden, to see the building industry’s opinion of</p><p>the product cellular concrete. The survey showed that cellular concrete was equals its</p><p>competitors in terms of price, while the product was said to be more flexible, quicker</p><p>and easier to cast.</p><p>Then some of the companies, who participated in the survey, were interviewed to see</p><p>more carefully, how the price, the workmanship and the time for casting and</p><p>dehydration differed between the products. Meanwhile, technical data were presented</p><p>for the products which formed the basis for the U-value calculation and the weight</p><p>analysis.</p><p>The result of this work was that LECA concrete is the cheapest option, when the Uvalue</p><p>is 0,40 W/(mK) and when the total thickness, including the following works, is</p><p>200 mm. Cellular concrete was found to be cheaper than foam concrete in small</p><p>quantities, in the both cases, since the foam concrete must be cast in multiple layers.</p><p>In addition, foam concrete requires more equipment, which results in a higher fixed</p><p>cost. Foam concrete becomes, however, more profitable the larger volumes that are</p><p>cast, because the fixed charges of the product are earned by the low volume cost.</p><p>Cellular concrete is suitable for smaller works, especially in tight spaces where some</p><p>insulation is required. Larger volumes are not beneficial because of the high volume</p><p>cost. Often, the weight may be decisive in the method and material selection. On these</p><p>occasions, the cellular concrete advantages through both low weight per unit volume</p><p>and good thermal insulation. To screed the cellular concrete has been shown to cause</p><p>large additional costs. At times, when no need to screed the concrete surface has</p><p>occurred, the total cost of the product almost halved. Cellular concrete should not be</p><p>cast in layers thinner than 50 mm.</p><p>LECA concrete must be cast in a layer of at least 100 – 120 mm that sufficient</p><p>adhesion can be obtained. This makes the product unsuitable for small castings,</p><p>including castings of the existing joists below 100 mm, but works well as foundations.</p><p>Of those described options, foam concrete is most suitable in larger castings.</p><p>However, it appears that the main use of foam concrete has been shown to be as a</p><p>filling material in road embankments.</p>
3

En funktion- och miljöpåverkansanlays av materialet isobetong / A Property and Environmental Analysis of the Material Isobetong

Rosencrantz, Eric, Saether, Oskar January 2020 (has links)
Byggbranschen utvecklas konstant, strävan efter att utveckla nya och effektivare material ärstor. Några av de viktigaste egenskaperna som byggsektorn eftersöker är hög hållfasthet, lågvärmekonduktivitet och låg miljöpåverkan.Isobetong är ett nyligen framtaget material. Det är en typ av skumbetong med egenskaper ochfunktioner som skiljer sig från traditionell skumbetong ur hänseende på hållfasthet,värmekonduktivitet och miljöpåverkan.Syftet med denna undersökning är att identifiera Isobetongens karakteristiska egenskaper ochjämföra de med egenskaper av konkurrerande material. Resultatet föreslås tydliggöramaterialets styrkor och vidare utgöra en grund för fortsatt undersökning samt främja enutökad användning. De frågor vilket undersökningen formas kring är ’Vad har materialet förmiljöpåverkan?’ och ’Hur jämför sig materialet mot mineralull och cellplast gällande funktionoch miljöpåverkan?’.Resultatet visar att miljöpåverkan av materialet Isobetong varierar från 65,5 kg CO2-ekvivalenter per kubikmeter för dess produkt med lägst densitet, upp till 230,7 kg CO2-ekvivalenter per kubikmeter för produkten med högst densitet. Beräkningarna som utförts ijämförande syfte tyder på att Isobetong i genomsnitt inte är likställd med cellplast ellermineralull inom områdena för densitet, värmekonduktivitet och miljöpåverkan. Resultatet förtryckhållfastheten av Isobetong ger ett betydligt högre värde än de övriga materialen.Slutsatsen är att relativt mot de jämförda materialen kan inte Isobetong konkurrera med varesig cellplast- eller mineralullsisoleringar då högre krav ställs på densitet, värmekonduktivitetoch miljöpåverkan. I projekt där en god tryckhållfasthet krävs har Isobetong en klar fördel. / The construction industry is continuously developing, the strive to develop new and moreefficient materials is great. In the industry, some of the most sought for properties of theimproved materials are high strength, low thermal conductivity, and low environmentalimpact.Isobetong is a recently developed material. It is a variety of foam concrete with properties thatdiffer from traditional foam concrete regarding strength, thermal conductivity, andenvironmental impact.The purpose of this analysis is to identify characteristic properties of Isobetong and tocompare them to the properties of competitive materials. The results are proposed to clarifythe material’s strengths and to furthermore act as a foundation for continued research as wellas encouraging an increased usage. The questions the analysis is based on are ‘What is theenvironmental impact of the material?’ and ‘How does the material compare to mineral wooland polystyrene?’.The result displays an environmental impact of the material Isobetong to vary between 65,5kg CO2-equivalents per cubic meter for the product with the lowest density, up to 230,7 kgCO2-equivalents per cubic meter for the product with the highest density. The computationsthat have been completed for comparative purposes indicates that Isobetong on average is notequal to polystyrene or mineral wool in areas of density, thermal conductivity, orenvironmental impact. The result for the compressive strength of Isobetong yield aconsiderably higher value than the other materials.The conclusion is that relative to the compared materials is Isobetong unable to compete withneither polystyrene or mineral wool insulations when higher requirements are set for density,thermal conductivity, and environmental impact. For projects that require a notablecompressive strength does Isobetong show a clear advantage.

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