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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.
31

Fuktrelaterade risker vid lågenergikonstruktion i lättbetong : En studie av ett nyproducerat passivhus / Moisture related risks with aerated concrete in low energy constructions : A study of a newly produced passive house

Jansson, Sebastian, Niklasson, Erik January 2014 (has links)
Trenden i byggbranschen är att efterfrågan på täta, energisnåla byggnader ökar. Passivhus och andra lågenergikonstruktioner blir vanligare och vanligare. Riskerna med att bygga in organiskt material som trä i dessa konstruktioner har fått branschen att börja titta på alternativa material. Lättbetong är ett material som både har bärande och isolerande egenskaper. Dessutom är det inte organiskt vilket gör det okänsligt för mikrobiell påväxt. Det som är intressant med lättbetong, ur fuktsynpunkt, är att materialet levereras från tillverkare med en stor mängd byggfukt. Våren 2014 färdigställde Bollnäs Bostäder passivhus- projektet Sundsbro i Bollnäs, där lättbetong ingår i utfackningsväggarna. Sett inifrån består väggen av ett tunt lager kc-puts, lättbetong, cellplast, mineralull, kc-baserad grovputs och ytputs. I detta arbete användes projektet i Bollnäs som referensobjekt och en risk- och känslighetsanalys av väggkonstruktionen utfördes. Arbetet utreder risken för fuktrelaterade problem med väggen vid de extra uttorkningsinsatser som vidtogs i referensobjektet och vid normala uttorkningsbetingelser. Vidare utreds vilka parametrar som är viktiga för väggens fuktfunktion och vad man behöver tänka på när man projekterar och bygger i lättbetong. Arbetet har genomförts i samarbete med AK-Konsult Indoor Air AB och deras senior konsult Anders Kumlin. Fuktberäkningsprogrammet WUFI Pro 5.3 har använts för simuleringar. Beräkningarna gjordes endimensionellt på väggkonstruktionen. Resultaten med den ökade uttorkning som utfördes i referensobjektet visar inget högre fuktinnehåll längst ut i väggen på grund av byggfukt från lättbetongen som vandrar utåt. Farhågan var att så skulle kunna ske och att det skulle kunna leda till mögelproblem. Däremot visar resultaten att bygg-fukt från putsen kan fukta upp mineralullen. Det finns dock inga kända skadefall av detta slag och därför dras ändå slutsatsen att konstruktionen är riskfri. Tack vare en förutseende fukt-projektering och väl utförd uttorkning eliminerades risken för mögel. Hade inte dessa åtgärder vidtagits så visar resultaten att en liten mängd byggfukt hade kunnat vandra utåt och kondensera i mineralullen under första vintern. Då hade det funnits risk för mikrobiell påväxt. Detta visar att det är av största vikt att utföra en noggrann fuktprojektering vid byggnation av välisolerade hus i allmänhet och i synnerhet när lättbetong används. Lyckligtvis gjordes detta på ett bra sätt i referensprojektet. Känslighetsanalysen visar att isoleringens diffusionstäthet är avgörande för hur stor del av bygg-fukten som kan vandra utåt och därmed hur stor risken för problem blir. Lägre täthet ger större risk och högre täthet reducerar risken. Resultaten visar också att det är viktigt att inte montera täta skikt på insidan för tidigt. Den allmänna rekommendationen från leverantör är att lättbetongen skall torkas till 15 % fuktkvot på 50 millimeters djup innan målning och tapetsering på insida vägg får ske. Studien visar att detta är ett för högt fukttillstånd om det skikt som appliceras på insida vägg är tätt. Lättbetongen bör torkas till 5 % på 50 millimeters djup innan helt täta skikt kan monteras utan mögelrisk. / The trend in the construction industry is that the demand for tight, energy-saving buildings is rising. Passive houses and low energy constructions are becoming more and more common. The risk with using organic material in this type of constructions has made the industry look at alternative materials. Aerated concrete is a material that has both load-bearing and insulating properties. In addition to that it is not organic, which makes it insensitive to microbial growth. What is interesting with aerated concrete, from a moisture point of view, is that the material is delivered from the producer with a large amount of construction moisture. In the spring of 2014, the passive-house project Sundsbro in Bollnäs with aerated concrete in the wall construction, was finished by Bollnäs Bostäder. In this study the project in Bollnäs was used as reference object and a risk- and sensitivity analysis was made. The study examines the risk of moisture related problems with the wall construction during normal dehydration conditions and after the increased dehydration efforts that were taken in the reference project. The study also examines which parameters are important for the moisture function of the wall construction and what you need to think about when you project and build with aerated concrete. The job has been done in cooperation with AK-Konsult Indoor Air AB and their senior consultant Anders Kumlin. The moisture calculation program WUFI Pro 5.3 has been used for simulations. The results with the increased dehydration that was used in the reference project show no increased moisture content in the outer parts of the construction due to construction moisture from the concrete that wanders outwards. The concern was that so could happen and that it would lead to mould problems. However the results show that construction moisture from the exterior plaster can moisten the mineral wool. There are no known damage cases of this sort and therefore the conclusion is that the construction is free of risk. Thanks to a foreseeing moisture projection and a well performed dehydration the risk of mould was eliminated. If these measures would not have been taken, the results show that a small amount of construction moisture could have wandered outwards and condensed inside the mineral wool during the first winter. Then there would have been a risk of microbial growth. This shows that it is very important to carry out a detailed moisture projection when constructing well insulated houses in general and when using aerated concrete in particular. Fortunately this was properly done in the reference project. The sensitivity analysis shows that the diffusion resistance of the insulation decides how much of the construction moisture that can wander outwards and consequently the size of the problem risk. Results also show that it is crucial not to apply sealing layers on the inside of the wall too early. The general recommendation from the supplier is that the aerated concrete should be dried to 15 % moisture ratio on 50 millimeter depth before painting and paper hanging on the interior surface of the wall can be done. The study shows that the concrete still is too damp at that stage if the layer applied on the inside of the wall is impermeable. The concrete should be dried down to 5 % moisture ratio before sealing layers can be applied without mould risk.
32

Совершенствование наружных стен, выполняемых из газозолобетонных блоков, в многоэтажных каркасных жилых домах : магистерская диссертация / Improvement of external walls made of aerated concrete blocks in multi-storey frame residential buildings

Усьянцев, С. Д., Usyantsev, S. D. January 2021 (has links)
Работа посвящена изучению многослойных наружных ограждающих конструкций наружных стен многоэтажных жилых каркасных зданий. В современном строительстве такие конструкции выполняются как правило на основе блоков из ячеистого бетона (газозолобетонные блоки). Применение подобных решений оправдано благодаря своей тепловой эффективности. Однако дискуссионным остается вопрос о рациональности использования существующих решений стеновых ограждений, так как необходимость устройства нескольких слоев из различных конструкционных материалов приводит к увеличению трудоемкости возведения. Кроме того, многослойные решения наружных стен зданий предъявляют повышенные требования к качеству выполнения работ, к качеству решений по обеспечению совместной работы нескольких разнообразных по физическим параметрам слоев, и порой такие решения снижают эксплуатационную надежность стенового ограждения, что, к сожалению, нередко приводит к авариям и обрушениям конструкций. Основным вопросом, решенным в исследовании является нахождение наименее трудозатратного варианта ограждающей конструкции, который бы имел сопоставимые с существующими стенами характеристики, а также снижал вероятность ошибки при сооружении наружных стен, которые могут приводить к авариям конструкций. / Present work is devoted to the study of multilayer external enclosing structures of external walls of multi-storey residential frame buildings. In modern construction, such structures are usually made on the basis of aerated concrete blocks. The use of such solutions is justified due to its thermal efficiency. However, the question of the rationality of using existing solutions for wall fences remains debatable, since the need to install several layers of various structural materials leads to an increase in the complexity of construction. In addition, multilayer solutions for the outer walls of buildings place increased requirements for the quality of in place works and overall construction technical quality to ensure the proper action of joints consisted of several layers with various physical parameters, and sometimes such solutions reduce the operational reliability of the wall enclosure, which, unfortunately, often leads to accidents and collapse of structures. The main issue solved in the study is to find the least labor-intensive version of the enclosing structure, which would have characteristics comparable to existing walls, and also reduce the likelihood of errors in the construction of external walls, which can lead to structural failures.
33

LCC MSE Walls

Smith, Joel 08 December 2023 (has links) (PDF)
Lightweight cellular concrete (LCC) is mainly a mixture of water, cement, and foam bubbles. LCC generally has a cast density between 20-60 pcf and an air content between 49-84%. LCC is often used as a fill material because it has a low unit weight which reduces settlement. LCC is increasingly being considered as a backfill behind Mechanically Stabilized Earth (MSE) walls and embankments. Although engineers are using LCC in MSE walls or free face walls (MSE wall without the concrete panels or reinforcements), there is presently a lack of information regarding the performance and behavior of LCC to guide them. This research attempts to answer questions on the design of MSE walls backfilled with LCC and free face LCC walls by providing a well-documented case history and evaluating if LCC can be modeled as a c-ϕ material. A steel frame test box (10 ft wide x 12 ft long x 10 ft high) with a MSE wall on one side was constructed for the research. The box was filled with four lifts of LCC with steel ribbed-strip reinforcements extending into the LCC behind the MSE wall panels at the center of each lift. After the LCC was cured, two static load tests were performed by applying a surcharge load to the surface of the LCC. In one test, surcharge pressure was applied adjacent to the MSE wall to produce failure of the wall system. In a second test, the surcharge pressure was placed adjacent to a free face of the LCC to produce failure. String potentiometers (string pots), load cells, pressure plates, and strain gages were used to measure the behavior of the MSE wall and free face wall during testing. These two tests provided a comparison between LCC behavior with a MSE wall relative to a LCC free face. Failure of the free face wall with unreinforced LCC backfill in this test can be predicted using Rankine’s lateral force equation using a c-ϕ model. Failure angle at the base of the free face wall was between 51-63° which corresponds with an average friction angle (ϕ) of 24° and cohesion (c) of 1575 psf with an upper bound ϕ = 34° and a c = 1285 psf. The presence of reinforcements in the LCC backfill behind the MSE wall increased the capacity of the wall to hold a surcharge load. The presence of reinforcements in the LCC behind MSE walls also led to a much more ductile surcharge pressure vs. lateral deflection curve for the MSE wall compared to the free face wall.
34

Střelnice & lasergame aréna „Eagle eye“ / Shooting range & lasergame arena "Eagle Eye"

Javůrek, Martin January 2018 (has links)
The subject of this project is a new building of a shooting range and lasergame arena in Brno, district Královo pole. The aim of the thesis is to create a documentation for realization of a shooting range and lasergame arena. It is a stand-alone two-storey building without the basement. The building is based on piled foundations, the construction system is reinforced concrete frame, infill material is light concrete brick. There is an exception: in the tunnel shooting range, there are monolithic reinforced concrete walls. The ceilings above the first floor are made also of reinforced concrete, the ceiling above the second floor / roof is made of pre-stressed reinforced concrete roof panels of spiroll type. There is flat, single-layer roof. The walls are designed as double-layered, contact-insulated with fiber-cement cladding.
35

Studium mikrostruktury autoklávovaného pórobetonu s využitím druhotných surovin / Study of microstructure of autoclaved aerated concrete with using of secondary raw materials

Martanová, Jana January 2018 (has links)
Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.
36

Skladovací areál s administrativní budovou / Storage area with administrative building

Šesták, Tomáš January 2019 (has links)
This master thesis focused on the design and elaboration of project documentation for the purpose of a storage area with an administrative building, consisting of the premises SO 01 - storage hall and SO 02 - administrative building. Objects are located on parcels no. 4006/16, 4006/17, 4006/18, 4006/19, 4006/23, 4006/24, 4006/26, 4006/27, 4006/28, 4006/29, 4006/30, 4006/31, 4006/32, in the cadastre unit Dolní Bojanovice. They are located on an investor's land. Traffic connection is provided by the exit from the car park on the local road. All engineering infrastructure engineering networks are located near the site. The design of the building respects the local zoning plan. Project documentation is prepared in accordance with the current wording of applicable laws, decrees and standards. The project solves the structure functionally divided into objects SO 01 and SO 02, which are both operationally and structurally connected. The construction of objects is statically independent. The object SO 01 is designed for the storage of building material intended for storage in dry rooms. In addition to the storage space there is the air-conditioning machine room. The SO 02 facility serves administrative and staffing facilities. In the basement of the building there are rooms of technical background and archives. The SO 01 is designed as a full-metal mounted object with a counter roof and foundation pads. The design system of the SO 01 object is columnar with steel columns. The SO 02 building is designed from a wall construction system made of aerated concrete blocks with reinforced concrete ceilings, base strips and a flat roof. The SO 01 has a 65.5x20.2 m ground plan. The perimeter shell of the building consists of assembled sandwich panels with a core of pure material. The largest ground plan dimensions of the so 02 are 26.75x10.35 m. The perimeter shell is made up of 375 mm piece concrete blocks with a 150 mm contact system.
37

Interakce mikrovlnného záření s vlhkostí v prostředí pórovitého staviva / Interaction of microwave radiation with moisture in porous building materials

Paťha, Martin January 2020 (has links)
This thesis deals with interaction of microwave radiation with wet in porous material. It examines the distribution of the temperature field, the efficiency of the method and the financial demands of the method. The most important part of this thesis was an experiment, from which all important values ??were based. The first part deals with the necessary theory and the second part is the experiment itself. The experiment was carried out for three levels of material wet. Eight samples were used for this experiment, which remained unchanged throughout the experiment. The thesis draws on previous researches that were carried out on this or similar topic.
38

Autosalon se servisem / Car dealership with auto repair shop

Wilkonský, Roman January 2015 (has links)
This diploma thesis is being solved for documentation of building in the stage of execution. The building is designed as a showroom with car repair shop. The building site is located in the land registry of Ostrava – Vítkovice. Project documentation is designed accordingly to the valid Czech Republic’s laws, bills and building standards. The building is divided into two objects the first one is showroom with administration and the second one is the car repair shop with washing room and restrooms. These two objects are structurally and operationally connected. The largest plan dimensions are 68,56 x 38,36 m. The building is designed as a reinforced concrete frame in the administrative part and a reinforced concrete wall system in the car repair part. The roof is in both cases realized by using steel trusses. The reinforced concrete frame is lined with aerated concrete masonry. In the roof part it is cladded with sandwich steel panels. The building is founded on reinforced concrete foundation pads with combination of strip foundations. The car repair shop is designed as one floor building, whereas the administrative part is designed as two floor.
39

Vliv technologie výroby popílkového pórobetonu na vznik tobermoritických fází / The effect of fly ash aerated concrete production technology to formation of tobermoritic phases

Fleischhacker, Ján January 2016 (has links)
Autoclaved aerated concrete is long-time ecological building material with usefull properties. There needs to be done research of its mineralogical compound for reengineering the production. The main mineral compound of AAC is tobermorite, it increases its mechanical properties. In the presence study, we examine the usage of nature and artificial silicious materials. Also, we investigate the influence of sulfate and alumina admixtures, as well as fluidized bed combustion ash, which can be used as the lime and gypsum replacement. Closure of the study is design of the optimal raw material composition, also hydrothermal treatment of autoclaved aerated concrete. In relation to its mechanical properties, mineralogical composition and cost.
40

Veřejná knihovna s kavárnou / Public library with cafeteria

Vlach, Ondřej January 2016 (has links)
The aim of this diploma thesis is to create a detailed design of a public library with cafeteria. The building is situated in the developing city area of Jihlava in the cadastral area of Horní Kosov. It has four storeys above ground and no basement floor. The 4th floor has a smaller net floor area than the rest floors. The building is designed also for disabled people. The expected number of employees is 18 and the number of visitors is 150 in a daily average. An entrance to the property is on the Vrchlického street. There is a parking lot in front of the building with a total capacity of 50 parking spaces including three parking spaces for disabled. The cafeteria and its facilities are situated in the ground floor of the building. Browsing area is situated in the second and third floor. The type of the structure is a frame structure with infill walls made of aerated concrete. The building has a double-skin facade. The cladding of the facade is made of fibre-cement boards. There is a curtain wall designed at some sections of the facade. The building has a warm flat roof with a parapet wall and interior roof drains.

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