Håldäcksbjälklag är ett fördelaktigt bjälklagsalternativ på grund av dess många fördelar så som reducerad vikt och snabbt montage. Däremot har bland annat korta byggtider medfört att betongblandningar med lågt vct och hög andel cement efterfrågats av Strängbetongs kunder för att reducera risken för fuktproblematik, då en snabb uttorkning eftersträvas. Med en allt strängare och ambitiösare miljömålsättning har ett behov för att reducera andelen cement uppkommit. Vid en minskad cementmängd ökar således betongens vct vilket leder till en miljövänligare framställning samtidigt som en ekonomisk vinning erhålls. Syftet med undersökningen är därför att undersöka om olika betongblandningar med ett högre vct kan ersätta den nuvarande betongblandningen och samtidigt uppfylla förekommande uttorkningskrav. Detta skulle innebära fördelar för såväl producenterna som för beställarna. Betongen som undersökts i utredningen är av jordfuktig karaktär och är enbart avsedd för håldäckstillverkning. Uttorkningsprocessen som studeras motsvarar uttorkningen från tillverkning fram till montage. Fyra olika betongblandningar fördelade på tolv kuber kommer att undersökas i tre olika klimat och enbart uttorkningsmässiga skillnader mellan kuberna kommer att jämföras. Undersökningen baseras på mätdata som grundar på mätningar utförda av en auktoriserad fuktkonsult via Rådet för byggkompetens, RBK. Betongrecepten i utredningen har framtagits av Cementa. Litteraturstudier används även för att styrka påståenden och underlag som framkommer i rapporten. Resultatet från studien visar att de kuber som förvarats i inomhusklimatet och i klimatrummet har en linjär uttorkningsutveckling, till skillnad från kuberna som är placerade i utomhusklimatet som har en olinjär uttorkningsutveckling. I inomhusklimatet och i klimatrummet har kuberna med högre vct torkat ut mer än betongblandningarna med lägre vct (0,40 och 0,45), däremot är skillnaden i uttorkning minimal i kuberna som har förvarats utomhus. Den fastställda slutsatsen i undersökningen är att mer djupgående och längre mätstudier behövs för att säkerställa hur betonguttorkningen förändras i ett senare skede av uttorkningsprocessen. / Hollow-deck joists are an advantageous flooring alternative because of its many advantages such as reduced weight and rapid assembly. However, among other things, short construction times have meant that concrete mixes with low w/c ratio and high proportion of cement have been requested by Strängbetongs customers in order to reduce the risk of moisture problems, when a rapid drying out pursued. With an increasingly stringent and ambitious environmental goal, a need to reduce the proportion of cement has arisen. With a reduced amount of cement, the w/c ratio of the concrete increases, which leads to a more environmentally friendly production, while at the same time an economic gain is obtained. The purpose of the study is therefore to investigate whether different concrete mixes with a higher w/c ratio can replace the current concrete mix and at the same time meet existing drying requirements. This would mean benefits for both the producers and orderers. The concrete that has been investigated in the investigation is of a soil-moist nature and is only intended for hole-deck production. The drying process that is studied corresponds to the dehydration from production to assembly. Four different concrete mixes divided into twelve cubes will be investigated in three different climates and only dehydration differences between the cubes will be compared. The survey is based on measurement data that are based on measurements performed by an authorized moisture consultant at Rådet för byggkompetens, RBK. The concrete recipes in the investigation have been developed by Cementa. Literature studies are also used to substantiate claims and supporting documents that appear in the report. The results from the study show that the cubes stored in the indoor climate and in the climate room have a linear dehydration development, unlike the cubes located in the outdoor climate that has a nonlinear dehydration development. In the indoor climate and in the climate room, the cubes with higher w/c ratio have dried out more than the concrete mixtures with lower w/c ratio (0,40 and 0,45), however, the difference in dehydration is minimal in the cubes that have been stored outdoors. The established conclusion in the study is that more in-depth and longer measurement studies are needed to ensure how concrete dehydration changes at a later stage of the drying process.

No description available.

This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab. The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics. The background of the problem with moisture is that today’s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate. The contribution of moisture increases this problem when the relative humidity reaches 75 %, which in most cases promotes mould. Moisture comes with natural ventilation through the eaves due to outside humidity and precipitation finding its way in, and at the same time comes from the inside through openings or cracks on concrete slabs, ventilation ducts, and attic doors. Moisture also comes into the attic from building materials, especially from the concrete slabs that evaporate which gives off a lot of moisture throughout the years. These things are possible to prevent with four different methods ventilation, sealing, heating or insulating the outer roof. Moisture effects are calculated from the examples given by Roxull FuktFakta in comparison with the authors own calculations from other databases. The object of reference, Bergahojden 6, is a residential building that has served as a model for all the calculations. The conclusion shows that air circulation has to increase to get out the moisture through the ventilation. The winters here in Sweden are so humid that the ventilation should be suitable enough so that the humidity does not rise above 75 % in the attic. To heat up the attic with devices, or by using roof insulation, would bring the same climate as the outdated slab insulations. There will be a big loss of energy with heat going out if the roof is not insulated. To apply both systems would be a double investment which would be hard to convince builders of. The conclusion is that the best method would be to combine sealing with ventilation, or a possible mechanical system which allows the attic to be ventilated during the summer and sealed during the winter.

<p>This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab.</p><p>The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics.</p><p>The background of the problem with moisture is that today’s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate. The contribution of moisture increases this problem when the relative humidity reaches 75 %, which in most cases promotes mould. Moisture comes with natural ventilation through the eaves due to outside humidity and precipitation finding its way in, and at the same time comes from the inside through openings or cracks on concrete slabs, ventilation ducts, and attic doors. </p><p>Moisture also comes into the attic from building materials, especially from the concrete slabs that evaporate which gives off a lot of moisture throughout the years. These things are possible to prevent with four different methods ventilation, sealing, heating or insulating the outer roof. </p><p>Moisture effects are calculated from the examples given by Roxull FuktFakta in comparison with the authors own calculations from other databases. The object of reference, Bergahojden 6, is a residential building that has served as a model for all the calculations. The conclusion shows that air circulation has to increase to get out the moisture through the ventilation. The winters here in Sweden are so humid that the ventilation should be suitable enough so that the humidity does not rise above 75 % in the attic. </p><p>To heat up the attic with devices, or by using roof insulation, would bring the same climate as the outdated slab insulations. There will be a big loss of energy with heat going out if the roof is not insulated. To apply both systems would be a double investment which would be hard to convince builders of. </p><p>The conclusion is that the best method would be to combine sealing with ventilation, or a possible mechanical system which allows the attic to be ventilated during the summer and sealed during the winter.</p>

With a goal to be able to cast a concrete slab and to dry out the moisture in the concrete in a faster way. To meet the requirement for certification of green building construction, the concrete slab must be dried out to an approved level before it is covered with a flooring material. This sets becomes a problem when today's buildings must be constructed quickly. Normal concrete slabs with 0.55 w/c take several years to dry out to the required levels. In this study we have looked at the parameters of concrete casting and how these affect the drying time. Calculations have been made in software with respect to weather, coverage, depth of water cement number and temperature at casting. Alternative methods have also been investigated such as separating the edge stiffening from the slab. The results show that changing the w/c or pouring with a cold concrete improves the drying process a lot.

Bakgrunden till det här examensarbetet var en artikel i byggvärlden som tog upp hur en nybyggd fastighet i Skövde hade drabbats av fuktproblem. Med anledning av detta startades en utredning av SBUF som visade på att fuktproblemen berodde på att en ny sorts betong som innehåll mineraltillsatser användes. Man kom också fram till att problemen som uppstod berodde på att den nya, moderna betongen får förändrade fuktegenskaper när man tillsätter mineraltillsatser.Syftet med detta examensarbete var att genom en litteraturstudie avgöra hur den traditionella betongens uttorkningsegenskaper påverkas av de tillsatser som idag används för att göra den moderna betongen mer klimatsmart. Syftet var också att ta reda på om den nya betongens uttorkningsegenskaper har några fördelar som kan användas i verkligheten vid en nybyggnation.Det visar sig att den moderna betongen med mineraltillsats har en tätare porstruktur som gör att uttorkningen för den moderna betongen fördröjs. Diffusionsuttorkning sker i så liten utsträckning att den i princip inte existerar. Detta sågs först som negativa egenskaper, vilket det är när man pratar om uttorkning. Men det som byggföretagens koncept nu har visat är att det finns stora potential till att vända dessa fuktegenskaper till något positivt. Konceptet bygger på att man uppnår en tillräcklig täthet i betongen som tillsammans med ett lager avjämning räcker för att få en fuktsäker konstruktion.Konceptet har även visat sig ha potential till att spara in på kostnader i och med att byggtider kan förkortas. Den moderna betongen är även ett miljövänligare alternativ. Lösningen med att använda ett lager avjämning är endast ett koncept som byggföretagen har testat, som nu har visat sig fungera, men som också förutsätter att man gör på ett visst sätt.Man bör ha i åtanke att för att detta koncept ska bli till ett standardförfarande i framtiden återstår mycket att göra så som mer testning. En pålitlig mätmetod behöver också tas fram för att mäta täthet i betong. Under testningen av konceptet mättes aldrig tätheten i betongen utan man provade sig fram och antog att 3 månader skulle ge den önskade tätheten. Vilket det också gjorde.Byggföretagens utredning visade också att alla betongrecept inte fungerar för att uppnå tillräcklig täthet i betong. Detta beror på vattencementtalet och att en tillräcklig täthet uppnås. Detta koncept fungerar inte heller på en traditionell betong med ordinarie portlandcement då den sortens betong inte innehåller mineraltillsatser som gör att betongen utvecklar tätheten som behövs. / The background to this thesis was an article in the construction world that addressed how a newly built property in Skövde had been affected by moisture problems. Due to this, an investigation was started by SBUF which showed that the moisture problems were due to the use of a new type of concrete containing mineral additives. It was also concluded that the problems that arose were due to the new, modern concrete having changed moisture properties when adding mineral additives.The purpose of this thesis was to determine through a literature study how the drying properties of traditional concrete are affected by the additives used today to make modern concrete more climate smart. The purpose was also to find out whether the drying properties of the new concrete have any advantages that can be used in reality in a new construction.It turns out that the modern concrete with mineral additive has a denser pore structure which means that the dehydration of the modern concrete is delayed. Diffusion drying takes place to such a small extent that it in principle does not exist. This was first seen as a negative trait, which is when talking about dehydration. But what the construction companies' concept has now shown is that there is great potential for turning these moisture properties into something positive. The concept is based on achieving a sufficient density in the concrete which, together with a layer of leveling, is sufficient to obtain a moisture-proof construction.The concept has also been shown to have the potential to save on costs as construction times can be shortened. Modern concrete is also a more environmentally friendly alternative. The solution of using a layer of leveling is only a concept that the construction companies have tested, which has now been shown to work, but which also presupposes that you do it in a certain way.It should be borne in mind that in order for this concept to become a standard procedure in the future, much remains to be done, such as more testing. A reliable measurement method also needs to be developed to measure density in concrete. During the testing of the concept, the density of the concrete was never measured, but it was tested and it was assumed that 3 months would give the desired density. Which it did.The construction companies' investigation also showed that not all concrete recipes work to achieve sufficient density in concrete. This is due to the water cement number and that a sufficient density is achieved. This concept also does not work on a traditional concrete with ordinary Portland cement as the type of concrete does not contain mineral additives which means that the concrete develops the density needed.

This thesis covers calculations of the equivalent measuring depth in the joint concrete between hollow-core slabs performed using the calculation and simulation program WUFI Pro. The calculations are based on input data from field measurements performed by Polygon|AK in Uppsala. Input from the company has been combined with a moisture profile from the calculation program Torka S to construct a basic model in WUFI. Simulations have been made based on the basic model with constant water-cement ratio in joint concrete, three varying parameters in terms of relative humidity in spackle, leveling height for spackle and vapor resistance in carpets. In order to get a broader result basis, 18 different typical cases for further analysis have been studied.  The calculation results indicate that the industry standard according to RBK, which states the equivalent measuring depth to 50 % of the hollow-core slabs joint height, does not correspond to the calculation basis for this work. The result of this work indicates that the actual equivalent measuring depth is about 15-18 % of the height of the joint, depending on the selected parameters. The difference between the industry standard and the result of this work can be explained by the fact that in the previous calculations of the equivalent measuring depth assumes a completely dense surface layer and no drying downwards and moisture from glue has not been taken into account. The assumption that the water contained in the cross section does not dry out and only redistributes leads to results that do not correspond to today's real conditions in terms of more diffusion-open carpets, moisture from carpet glue and different moisture conditions in spackle.

Byggandet av dagens sjukhus har blivit allt mer komplext. När det kommer till uppbyggnaden av stomkonstruktionen har kraven för vibrationer ökat. För att säkerställa kraven för stomvibrationer måste pågjutningens tjocklek öka med ca 90 mm från standarden som är ca 40 mm. Att utföra denna extra pågjutning är inte ett problem i sig, utan den extra torktiden som tillkommer. Den extra torktiden är inte det enda problemet. De beräkningsprogram som finns ute på marknaden idag kan inte behandla alla typer av konstruktioner och simuleringar, dock skulle det kunna gå att dela upp simuleringsprocessen för uttorkningen emellan beräkningsprogrammen. I denna studie så kommer två olika simulering/beräknings program att tillämpas. Beräkningsprogrammen som kommer att användas är TORKA S och WUFI. Torktiderna kommer att räknas fram genom att kombinera dessa program samt titta på tidigare studier gällande detta projekt. I denna studie har vi valt att ta en närmare titt på hur foggjutningen mellan håldäcken påverkar torktiden för hela delområdet, dvs. foggjutningen och pågjutningen. Resultaten visar att vct för foggjutningen måste vara betydligt lägre än vct för pågjutningen och att torktiderna varierar beroende på vct. Torktiderna för pågjutningen varierar om mätningar görs över fog eller mitt på håldäcken. / Constructions of hospitals today have become more complex than before. As for the construction of the frame structure, the requirements for vibration in the body have increased. To fulfill the requirements for frame vibrations the top coating thickness must be increased with 90 mm ​​from the standard thickness, which is around 40 mm. To perform this extra topping is not the biggest issue. The major problem is the extra drying time that is added in the process. Another large problem is the calculation programs that are available on the market today cannot deal with all types of designs and simulations; however it would be possible to divide the simulation process for the dehydration between different calculation programs. In this study, two different simulation/calculation programs will be used. The programs that will be applied are TorkaS 3.2 and WUFI Pro. Drying times will be generated by combining these programs and look at previous studies similar to this project. In this study we have chosen to take a closer look at how joint cast between the slabs affects the drying time for the entire sub-area, which is the joint cast and topping cast. The results of the w/c-ratio for joint cast must be significantly lower than w/c-ratio for topping and that drying times will vary depending on the w/c-ratio. Drying times for topping will also vary if measurements are made over the joint or middle of the slab.

Cementproduktion står idag för totalt 5 % av koldioxidutsläppen globalt, vilket t.ex. är mer än dubbelt så mycket som den globala flygindustrin. Nya cement- och betongrecept, med nya egenskaper, utvecklas med målet att minska klimatbelastningen. I produkten Bascement ersätts delar av klimatbelastande cementklinker med mineraltillsatsen flygaska, en restprodukt från andra industrier. Detta ska alltså leda till en minskad klimatbelastning. Betong med Bascement har dock orsakat förseningar och extra kostnader i produktion på grund av långa torktider som inte stämt överens med simuleringar i TorkaS 3.2, en programvara baserad på betong med Byggcement. TorkaS ska ersättas av programvaran Produktionsplanering Betong (PPB) som kan simulera uttorkning i betong med Bascement. Målet med studien är att undersöka hur fuktsimuleringar i PPB skiljer sig jämfört med genomförda fuktmätningar i fyra betongprover med två olika vattencementtal, vct. Genom att förvara proverna i olika miljö är målet att experimentellt mäta hur omgivningen påverkar uttorkningen. Målet är vidare att visa skillnader mellan fuktsimuleringar med inbyggd klimatdata i PPB och med egna uppmätta klimatdata. Resultaten från de experimentella undersökningarna visar att uttorkningen blev större i betongprover med vct 0,40 än för motsvarande prover med vct 0,55 efter 70 dagar. Prover som hade förvarats i en stabil inomhusmiljö hade torkat mer än prover som hade förvarats i en varierande utomhusmiljö, vilket i denna studie inte stämde överens med simuleringar i PPB. Resultatet i denna studie visar att simuleringar i PPB tenderar att visa något större uttorkning jämfört med genomförda fuktmätningar. Denna överskattning blir större vid simuleringar med en varierande utomhusmiljö än med en stabil inomhusmiljö. Överskattningen blir större vid simuleringar med inbyggd klimatdata i PPB än med egna uppmätta klimatdata. Vid justering av betongens maxtemperatur i PPB till verkligt uppmätt maxtemperatur påverkas fuktsimuleringarna positivt så att de närmar sig de experimentellt erhållna resultaten. Betong med låga vct påverkas mer av en sådan justering än höga vct. Slutsatsen i denna studie är baserad på simuleringar och fuktmätningar i ett fåtal betongprover, vilka kan ha utsatts för störningar. Fler studier behövs för att validera reliabiliteten hos programvaran PPB. Val av härdningsmetod samt maxtemperatur under härdning kan påverka uttorkningen och simuleringar i PPB. Experimenten indikerar att simuleringar med PPB tenderar att avvika om betong med höga vct utsätts för vattentillskott kort efter gjutning. Korrekt maxtemperatur i PPB är viktigt för en mer verklig simulering av uttorkning i betong, särskilt vid låga vct. Simuleringar i PPB tenderar att bli mer korrekta med egna klimatdata än med inbyggd klimatdata. / Cement production currently accounts for a total of 5 % of carbon dioxide emissions globally, which for example is more than twice as much as the global aviation industry. New cement and concrete recipes, with new properties, are being developed with the aim of reducing the climate load. In the Portland fly ash cement, parts of climate-stressing cement clinkers are replaced with the mineral-added fly ash, a residual product from other industries. This should lead to a reduced climate impact. Concrete with Portland fly ash cement, however, has caused delays and extra costs in production due to long drying times that did not match with simulations in the software TorkaS 3.2, which is based on concrete with Portland-limestone cement. TorkaS will be replaced by the software Production Planning Concrete, PPB, which can simulate dehydration in concrete with Portland fly ash cement. The aim of the study is to investigate how moisture simulations in PPB differ from executed moisture measurements in four concrete samples with two different w/c ratio. By storing the samples in different environments, the goal is to experimentally measure how the environment affects the dehydration. The goal is also to show differences between moisture simulations with the built-in climate data in PPB and with the own measured climate data. The results from the experimental studies show that the dehydration became larger in concrete samples with w/c ratio 0.40 than for samples with w/c ratio 0.55 after 70 days. Samples that had been stored in a stable indoor environment had dried more than samples that had been stored in a varying outdoor environment, which in this study did not correspond to simulations in PPB. The result of this study shows that simulations in PPB tend to show slightly greater dehydration than executed moisture measurements. This overestimation is greater in simulations with a varying outdoor environment than with a stable indoor environment. The overestimation is greater in simulations with the built-in climate data in PPB than with the own measured climate data. When adjusting the maximum temperature of the concrete in PPB to the actual measured maximum temperature, the moisture simulations is positively affected so that they approach the experimentally obtained results. Concrete with low w/c ratio is more affected by such an adjustment than concrete with high w/c ratio. The conclusion in this study is based on simulations and moisture measurements in a few concrete samples, which may have been exposed to disturbances. More studies are needed to validate the reliability of the PPB software. Choice of curing method and maximum temperature during curing can affect the drying and simulations in PPB. The experiments indicate that simulations with the PPB software tend to deviate if concrete with a high w/c ratio is exposed to water shortly after casting. Correct maximum temperature in PPB is important for a more real simulation of dehydration in concrete, especially at high w/c ratio. Simulations in PPB tend to be more accurate when using own climate data than using the built-in climate data.

When building a house or similar the stress on the ground increases and deformations can arise. The deformations create a foundation that the building is not constructed for and damages on the building arise. The increased stress on the ground can be derived back to the building, but it is possible that the increased stress may well derive from different sources such as other buildings or trees.         The building is an older property, built in the late 19th century alternatively early 20th century, and is today used for rental housing and has suffered severe damages due to subsidence. The goal of the thesis is to find possible causes for these subsidences.   The thesis was executed as a combination between literature- and casestudie.   After careful studies it has been found that a probable cause for these subsidences is trees. Through field- and lab studies it has been found that the trees has effected the ground through there accumulation of water. This has caused the soil to dry up and subsidence’s has probably arisen through the decrease in pore pressure due to the disappearing of water. This, however, needs to be proven by further studies of pore pressures in the area.