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1

Mao, Guofeng. "Thermal bridges." Doctoral thesis, KTH, Byggnader och installationer, 1997. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-2609.

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2

Johnson, Jeffrey Keith. "Concrete bridge deck behavior under thermal loads." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/johnson/JohnsonJ0805.pdf.

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3

Ibrahim, Ahmed M. M. "Three-dimensional thermal analysis of curved concrete box-girder bridges." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1995. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ43535.pdf.

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4

McBride, Kevyn C. "Thermal stresses in the superstructure of integral abutment bridges." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4331.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains x, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 115-122).
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5

Efretuei, Edet Okon. "Thermal impact on soil-structure interaction for integral bridges." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/4953/.

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Integral bridges are generally considered an attractive alternative to conventional bridges presenting the economic advantage of lower construction and maintenance costs. However, the concept of the integral bridge presents other challenges primarily arising from the monolithic connection that exists between the superstructure and the substructure. Thermal loading leads to daily cycles of expansion and contraction superimposed on seasonal cycles. This results in significantly higher soil-structure interaction activity that may lead to excessive earth pressures behind the abutment and potential failure of the soil and structure. A parametric study was carried out to evaluate the impact of change in the backfill soil parameters and change in the season of construction on the earth pressures developed behind the abutment. The frequency of the daily and seasonal cycles of expansion and contraction is such that granular soils respond as fully drained materials. This is seldom the case for fine grained soils. Excess pore pressures are developed and some drainage may occur. However, data and resource limitations make it not feasible to accurately model this over the long term. Further the need to make assumptions about the temperature cycles and the permeability characteristics weakens the strength of the analysis. Therefore, an envelope of earth pressure generation was created in these parametric studies by modelling fine grained soils as fully drained and fully undrained. Plaxis 2D was used to model the bridge and surrounding soil. In developing a realistic model of an integral bridge, the first stage was to simulate a constructed instrumented integral bridge which presented measured values of temperature, deformation and earth pressures in time. This allowed the model to be validated and the sensitivity of the analysis to the parameters assessed. A second simulation was undertaken to compare the output of an integral bridge analysis using Plaxis 2D finite element software with a published study output carried out using the finite difference method. There were a number of challenges to overcome in modelling an integral bridge. These are described in some detail, highlighting the impact the assumptions made within this studies, had upon the output. It was found that the backfill stiffness parameter was the dominant factor that controlled the magnitude of earth pressure. The parametric study revealed that the season of construction affected the earth pressures generated behind the abutment with autumn and summer construction often leading to cumulatively lower earth pressures than spring and winter respectively. In integral bridge construction, it is common to use granular soils in backfill construction. However, the use of granular soils in foundation construction may not be sustainable as a result of material availability and construction cost. Fine grained soils are alternatively used where granular soils are not. It was found that modelling fine grained foundation soils as fully drained and fully undrained produced significant variations in the behaviour of the backfill soil and the resulting earth pressure pattern. It is therefore necessary to take into account the impact of thermal loading on the envelope of earth pressure to ensure that the capacity of the structure and soils are not exceeded or underutilised.
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6

Suchinda, Chatr. "Experimental and analytical investigation of the thermal behavior of a fiber reinforced polymeric bridge deck." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/19250.

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7

Bettinger, Christopher L. "Effects of thermal expansion on a skewed semi-integral bridge." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1173468821.

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8

Dupuis, Kenneth J. "Nondestructive testing of concrete box girder bridges using thermal imaging." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Spring2008/K_Dupuis_040908.pdf.

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9

Dirks, Ryan. "Measuring Pixels: Using Grasshopper to Evaluate Thermal Bridges in Buildings." Thesis, University of Oregon, 2015. http://hdl.handle.net/1794/19206.

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Green design is now a ubiquitous term in the profession of architecture, yet the energy performance of buildings in real-world conditions is poorly documented. A large number of buildings use substantially more energy than is predicted during design, and one possible explanation is that designers do not adequately understand the impact of thermal bridging through insulation on the energy use of a building. This study proposes a methodology that uses the parametric design program Grasshopper to quantitatively analyze infrared images for the degree of thermal bridging in a wall assembly. The end result is a user-friendly tool that architects can use to study the relative energy performance of their buildings in the field, giving them an increased understanding of the energy efficiency of their designs. Case studies of various details show a ten to fifty-five percent reduction in the effective R-value of the overall wall assemblies due to thermal bridging.
10000-01-01
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10

Woodworth, Michael Allen. "Fire Hazard Assessment for Highway Bridges with Thermal Mechanical Modeling." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23683.

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Bridges are critical pieces of infrastructure important to public safety and welfare. Fires have the potential to damage bridges and have been responsible for taking many bridges out of service. The hazard fire poses to bridges is a little studied risk unlike more common threats such as impact, scour and earthquake. Information on the rate of occurrence of bridge fires and the mechanisms of structural response of bridges subjected to fire are both vital to policy makers seeking to address the hazard rationally.
The investigation presented developed frequency statistics of bridge fire incidents from several sources of vehicle accident and fire statistics. To further investigate the fire hazard a computational model integrating the simulation of large fires and the simulation of bridge superstructure mechanical response was created. The simulation was used to perform a parametric study of fire size and location to investigate the relationship between these parameters and damage tot bridge super-""structure. The statistics investigation resulted in an observed rate of fires due to vehicle accidents of approximately 175 per year. Approximately one of these per year was the result of a tanker truck carrying a flammable liquid leading to extensive superstructure damage. The simulation showed that a tanker fire resulted in permanent damage to the bridge by several measures where as the affects of a bus fire were minimal. The simulations also demonstrated the mechanisms of bridge response; the importance of girder temperature in that response; and the differences in the response to a tanker fire that can lead to collapse.
Ph. D.
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11

Kromanis, Rolands. "Structural performance evaluation of bridges : characterizing and integrating thermal response." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/17440.

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Bridge monitoring studies indicate that the quasi-static response of a bridge, while dependent on various input forces, is affected predominantly by variations in temperature. In many structures, the quasi-static response can even be approximated as equal to its thermal response. Consequently, interpretation of measurements from quasi-static monitoring requires accounting for the thermal response in measurements. Developing solutions to this challenge, which is critical to relate measurements to decision-making and thereby realize the full potential of SHM for bridge management, is the main focus of this research. This research proposes a data-driven approach referred to as temperature-based measurement interpretation (TB-MI) approach for structural performance evaluation of bridges based on continuous bridge monitoring. The approach characterizes and predicts thermal response of structures by exploiting the relationship between temperature distributions across a bridge and measured bridge response. The TB-MI approach has two components - (i) a regression-based thermal response prediction (RBTRP) methodology and (ii) an anomaly detection methodology. The RBTRP methodology generates models to predict real-time structural response from distributed temperature measurements. The anomaly detection methodology analyses prediction error signals, which are the differences between predicted and real-time response to detect the onset of anomaly events. In order to generate realistic data-sets for evaluating the proposed TB-MI approach, this research has built a small-scale truss structure in the laboratory as a test-bed. The truss is subject to accelerated diurnal temperature cycles using a system of heating lamps. Various damage scenarios are also simulated on this structure. This research further investigates if the underlying concept of using distributed temperature measurements to predict thermal response can be implemented using physics-based models. The case study of Cleddau Bridge is considered. This research also extends the general concept of predicting bridge response from knowledge of input loads to predict structural response due to traffic loads. Starting from the TB-MI approach, it creates an integrated approach for analyzing measured response due to both thermal and vehicular loads. The proposed approaches are evaluated on measurement time-histories from a number of case studies including numerical models, laboratory-scale truss and full-scale bridges. Results illustrate that the approaches accurately predicts thermal response, and that anomaly events are detectable using signal processing techniques such as signal subtraction method and cointegration. The study demonstrates that the proposed TB-MI approach is applicable for interpreting measurements from full-scale bridges, and can be integrated within a measurement interpretation platform for continuous bridge monitoring.
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12

Clark, John H. "Evaluation of thermal stresses in a concrete box girder bridge /." Thesis, Connect to this title online; UW restricted, 1989. http://hdl.handle.net/1773/10101.

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13

Shah, Bhavik Rameshchandra. "3D finite element analysis of integral abutment bridges subjected to thermal loading." Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/388.

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14

Garcia, Sandrine L. "Analysis of a space experimental design for high-Tc superconductive thermal bridges." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/42752.

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Infrared sensor satellites are used to monitor the conditions in the earth's upper atmosphere. In these systems, the electronic links connecting the cryogenically cooled infrared detectors to the significantly warmer amplification electronics act as thermal bridges and, consequently, the mission lifetimes of the satellites are limited due to cryogenic evaporation. High-temperature superconductor (HTS) materials have been proposed by researchers at the National Aeronautics and Space Administration Langley's Research Center (NASA-LaRC) as an alternative to the currently used manganin wires for electrical connection. The potential for using HTS films as thermal bridges has provided the motivation for the design and the analysis of a spaceflight experiment to evaluate the performance of this superconductive technology in the space environment The initial efforts were focused on the preliminary design of the experimental system which allows for the quantitative comparison of superconductive leads with manganin leads, and on the thermal conduction modeling of the proposed system (Lee, 1994). Most of the HTS materials were indicated to be potential replacements for the manganin wiresc In the continuation of this multi-year research, the objectives of this study were to evaluate the sources of heat transfer on the thermal bridges that have been neglected in the preliminary conductive model and then to develop a methodology for the estimation of the thermal conductivities of the HTS thennal bridges in space.

The Joule heating created by the electrical current through the manganin wires was incorporated as a volumetric heat source into the manganin conductive model. The radiative heat source on the HTS thermal bridges was determined by performing a separate radiant interchange analysis within a high-Tc superconductor housing area. Both heat sources indicated no significant contribution on the cryogenic heat load, which validates the results obtained in the preliminary conduction model.

A methodology was presented for the estimation of the thermal conductivities of the individual HTS thermal bridge materials and the effective thermal conductivities of the composite HTS thermal bridges as functions of temperature. This methodology included a sensitivity analysis and the demonstration of the estimation procedure using simulated data with added random errors. The thermal conductivities could not be estimated as functions of temperature; thus the effective thermal conductivities of the HTS thermal bridges were analyzed as constants.


Master of Science
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15

Tipirneni, Raja Ram. "Characterization of thermal and electrical properties of fiber reinforced polymer (FRP) composites." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5932.

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Thesis (M.S.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains xii, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 116-117).
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16

Sharpe, Graeme Peter. "Reflective cracking of shear keys in multi-beam bridges." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1912.

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17

Hurff, Jonathan B. "Stability of precast prestressed concrete bridge girders considering imperfections and thermal effects." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34684.

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The spans of precast prestressed concrete bridge girders have become longer to provide more economical and safer transportation structures. As the spans have increased, so has the depth of the girders which in turn have increased the slenderness of the girders. Slenderness in a beam or girder would increase the likelihood that a stability failure would occur. Stability failures could pose a danger to construction personnel due to the sudden nature in which a stability failure would occur. Furthermore, stability failures of prestressed concrete girders during construction would cause a detrimental economic impact due to the costs associated with the failure of the girder, the ensuing construction delays, damage to construction equipment and potential closures to highways over which the bridge was being constructed. An experimental and analytical study was performed to determine the stability behavior of prestressed concrete beams. Two stability phenomenons were investigated: (1) lateral-torsional buckling and (2) global stability. An emphasis was placed on the effects of initial imperfections on the stability behavior; the effect elastomeric bearing pads and support rotational stiffness was investigated. The experimental study involved testing six rectangular prestressed concrete beams for lateral-torsional buckling, a PCI BT-54 for thermal deformations and the same PCI BT-54 for global stability. The 32-ft. long rectangular beams were 4-in. wide and 40-in. deep. The PCI BT-54 had a 100-ft. long span. A material and geometric nonlinear, incremental load analysis was performed on the six rectangular beams. The nonlinear analyses matched the experimental load versus lateral displacement and load versus rotation behavior, and the analysis predicted the experimental maximum load within an error of 2%. The nonlinear analysis was extrapolated to several different initial imperfection conditions to parametrically study the effect of initial lateral displacement and initial rotation on the inelastic lateral-torsional buckling load. A simplified expression for lateral-torsional stability of beams with initial imperfections was developed. The data from the parametric study were used to develop reduction parameters for both initial sweep and initial rotation. The rollover stability behavior of the PCI BT-54 was investigated experimentally, and it was found that support end rotations and the elastomeric bearing pads had an adverse effect on the global stability. The nonlinear analysis was employed with the addition of a bearing pad model. It was found that the behavior was sensitive to the bearing pad stiffness properties and the assumption of uniform bearing. From the research, it was apparent that rollover stability was the controlling stability phenomenon for precast prestressed concrete bridge girders, not lateral-torsional buckling.
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18

Rouhani, Siamak. "Temperature analyses of Concrete Frame Bridges with Finite Elements." Thesis, KTH, Bro- och stålbyggnad, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145904.

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FE-modeling is a rapidly spreading method to analyze structures nowadays. With this theunderstanding of the outcome is of very high importance and potential inaccuracies areimportant to find so that faulty and over dimensioning of the structure does not occur whichleads to unnecessary costs. One of these inaccuracies is the unrealistic sectional forces that occurdue to thermal effects in the transversal direction for concrete frame bridges which leads to anexcessive amount much reinforcement in the structure than actually needed. This has beenstudied with several cases by using two approaches on how to apply the temperature in the framebridge, only in the superstructure and in the whole structure, but also by analyzing severalboundary conditions. By examining the results for the sectional forces and stresses one of thetemperature approaches could be disregarded because of the extreme values in the transitionbetween superstructure and support. But the other approach was much more useful because ofits better compliance with reality. With these results and by calculating the reinforcement neededfor the worst case, one model has been found to be the most favorable and can be used whenmodeling concrete frame bridges with acceptable outcome. The study resulted in a model whereone applies a varying temperature on the whole structure, with spring boundary conditions over asurface that represents the bottom slab.
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19

Currier, Nathan. "Validation of stresses caused by thermal gradients in segmental concrete bridges - phase II." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0025154.

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20

Gkorogias, Panagiotis, and Susanna Gerges. "Concrete sandwich element design in terms of Passive Housing recommendations and moisture safety." Thesis, KTH, Byggvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-168734.

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In this thesis project a concrete sandwich wall element of 250 mm insulation of Kooltherm has been resulted to have U-values and ψ-values closer to the passive housing recommendations. However, by using 180 mm thick insulation, no significant difference in the annual energy consumption is observed. Using a metal sheet in the window connection and small concrete brackets, low thermal bridge values are achieved. Low thermal bridge coefficient values were also observed with thick insulation in the foundation and the roof structure, although, it is impossible to achieve values below 0,01 W/mK in the corner connections. Airtightness of the building envelope is more important than the thickness of the wall in the energy consumption simulations. Therefore, the thermal bridging and the U-values of the wall are, in most cases, dependent on the thickness of the element. No conclusions on the structural reliability of the solutions can be extracted from this thesis project. In order to conclude the statements above, this thesis project has been focused on the evaluation and design of a concrete sandwich wall panel. The design of the wall element, including its reinforcement and connectors, while achieving values according to passive housing regulations, is the initial goal of this project. Subsequently, connections between the building components and the wall element are analyzed and designed through several simulations according to the passive housing regulations respectively. Simulation tests took place in Sweco Structures AB offices with the valuable contribution of experts. An existing building project was used and evaluated in order to present the simulation results in a more realistic manner. Several insulation materials have been tested for the thermal and moisture reliability. Using the existing building as a base for information, energy simulations generated the energy consumption results in order to compare different wall thicknesses, and thermal bridging effects. This project is inspired by the needs of building sustainability and efficiency, which has become a significant part of the worldwide effort on reducing the energy consumption on the planet. Regulations regarding building technology have been completely changed and adjusted in the passive housing design. Particular effort has been put on the commercial and multi-residential buildings, in which the energy consumption is usually higher than in small family houses. Concrete sandwich wall panels have been introduced in the building market as an alternative and more efficient way of constructing. Prefabrication has been proved to be less time consuming, although issues on the thermal behavior appear in this kind of structure. The evaluation of the thermal efficiency of the concrete sandwich wall elements has been a significant issue in the civil engineering society and research.
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21

Noremo, Tom. "Skapandet av ett byggnadsfysikaliskt detaljbibliotek åt byggnadskonstruktörer : fokus på fukt- och värmetillstånd i köldbryggor." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-12161.

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Det konstrueras i stor utsträckning bristfälliga detaljlösningar på byggnader i dagsläget. Den bärande stommen i konstruktionen prioriteras ofta medan det inte ägnas lika mycket fokus åt att tillgodose de byggnadsfysiska aspekterna. Anledningen till de bristfälliga detaljerna är även att den som utför arbetet saknar rätt kunskap och tid. För att skapa en förbättring behövs ett hjälpmedel! Kunskap och erfarenhet om hur bra detaljer skapas finns redan i företag, svårigheten är dock att sprida kunskapen till de som är i behov av den. Målet med denna rapport är att skapa en metodik som blir startskottet för ett omfattande arbete kring framtagandet av ett detaljbibliotek, vars syfte är att sprida byggnadsfysiska kunskaper inom företaget och inspirera konstruktörer till att konstruera bra detaljlösningar. Biblioteket ska innehålla byggnadsfysiskt utredda detaljlösningar som analyserats enligt den utarbetade metodiken. Metodiken kommer göra det möjligt att på ett enkelt sätt utvärdera detaljlösningar, för att sedan presentera dessa med uträknade värden och rekommendationer i detaljbiblioteket. Via intervjuer med konstruktörer och en omfattande genomgång av byggnadsprojekt, har 7st detaljlösningar valts ut för att utredas och sedan exemplifiera hur dokumenten i detaljbiblioteket kommer att gestalta sig. Exemplen går att se i rapporten, och de kommer även att utgöra embryot till det slutgiltiga detaljbiblioteket. Detaljbiblioteket kommer sedan ligga ute på Sweco Structures interna nätverk, så att detaljerna blir lättåtkomliga för de som är i behov av dem.
It is constructed inadequate detail solutions of buildings in the current situation. The carrying frame of the structure is often given priority while it is not given as much focus to solve the building physical aspects. The reason for the inadequate detail is also that the person doing the don´t has the right knowledge or time. In order to create an improvement, a tool is needed!  Knowledge and experience of how well the details are created already exists at the company, the difficulty is to spread the knowledge to those who are in need of it. The objective of this report is to create a methodology that will mark the start of an extensive work on the development of a detail library whose purpose is to spread building physical skills within the company and inspire constructors to construct good detail solutions. The library will include good building physical detail solutions which were analyzed according to the produced methodology. The method will allow to easily evaluate detail solutions, and to present them with calculated values and recommendations in detail library. Through interviews with designers and a comprehensive review of construction projects, has 7 detail solutions been selected to be examined, and then illustrate how the documents in detail the library will be presented. The examples will be seen in the report, and they will also serve as the embryo of the definitive and large detail library. Detailed library will then be placed at Sweco Structures internal network, so that the details are easily accessible for those who are in need of them.
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22

Musgrove, Ryan Ross. "Nondestructive detection of post-tensioning tendons and simulated voids in concrete specimens using thermal imaging." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Spring2006/r%5Fmusgrove%5F012506.pdf.

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23

Lee, Kasey M. "Experimental design for the evaluation of high-Tc superconductive thermal bridges in a sensor satellite." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06302009-040459/.

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24

Arenas, Alfredo Eduardo. "Thermal Response of Integral Abutment Bridges With Mse Walls: Numerical Analyses and a Practical Analysis Tool." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/30134.

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The advantages of Integral Abutment Bridges (IABs) include reduced maintenance costs and increased useful life spans. However, comprehensive and practical analysis tools for design of IABs have not been developed to account for the impacts of thermal displacements on abutment and foundation components, including the components of mechanically stabilized earth (MSE) walls that are often used around the abutment piling. During this research, over 65 three-dimensional numerical analyses were performed to investigate and quantify how different structural and geotechnical bridge components behave during thermal expansion and contraction of the bridge deck. In addition, separate three-dimensional numerical models were developed to evaluate the usefulness of corrugated steel pipes around the abutment piles. The results of this research quantify the influence of design parameter variations on the effects of thermal displacement on system components, and thus provide guidelines for IAB design, where none had existed before. One of the findings is that corrugated steel pipes around abutment piles are not necessary. One of the most important products of this research is an easy-to-use Excel spreadsheet, named IAB v2, that not only quantifies the impact of thermal displacement in the longitudinal direction, but also in the transverse direction when the abutment wall is at a skew angle to the bridge alignment. The spreadsheet accommodates seven different pile sizes, which can be oriented in weak or strong directions, with variable offset of the abutment from the MSE wall and for variable skew angles. The spreadsheet calculates the increment of displacements, forces, moments, and pressures on systems components due to thermal displacement of IABs.
Ph. D.
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25

Ledin, Jonatan, and Christensen Oskar. "Cracking Assessment of Concrete Slab Frame Bridges Exposed to Thermally Induced Restraint Forces." Thesis, KTH, Betongbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169588.

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The usage of linear 3D FEA is widespread within the bridge design community, and although this tool provides substantial benefits in the design process, there are certain practical issues related to the application of this analysis tool. A situation in which such an issue prevails is when linear 3D FEA is used to analyze restraint forces due to thermal shrinkage or expansion in concrete slab frame bridges. Effects related to restraint forces in concrete are difficult to model and predict as these forces differ significantly in nature from external loads, and dealing with them in practical design situations is complicated. In this thesis, cracking due to restraint forces in concrete slab frame bridges was investigated using 3D non-linear FE-analyses in the software package ATENA 3D. Using volumetric finite elements, attempts were made to realistically capture the load response and cracking behavior of concrete slab frame bridges subjected to restraint forces induced by temperature differences among members. The initial parts of this thesis aims to find appropriate modelling techniques and material models for the prediction of cracks due to restraint forces in base restrained walls using a previously reported experimental research project as reference. Comparative simulations were performed, using crack widths and crack patterns as comparate. Overall good correspondence was obtained with an exception of deviation in cracks formed at locations near the restrained corners where crack widths were overestimated in the simulations. The technique used to model the restrained boundary proved to be highly influential in the context of obtaining realistic results. Subsequent to the comparative study, a parametric study was performed where the correlation between crack widths and selected attributes was investigated. The parameter which exhibited the most distinct influential effect on the results was the length-to-height (L/H) ratio of the wall. The applicability of a crack control approach intended for crack width estimation in liquid retaining and containment structures made of concrete exposed to thermally induced restraint forces, given in EN 1992-3, was then evaluated for use in design of concrete frame bridges. This approach proved to return conservative results for walls with low L/H-ratios when compared to results produced in the numerical simulations. Finally, a NLFE (non-linear finite element) model of a concrete slab frame bridge designed by the consultancy company Tyréns AB was composed and tested. Different procedures of applying temperature differences between front wall and bridge deck were evaluated. This study indicated that the width of cracks induced by lateral restraint forces decreased when temperature was modelled applying a discrete thermal gradient to members in contact with back filling material compared to using a uniform temperature in these members when temperature differences between bridge deck and wall was simulated. The interacting effects of permanent external load effects and restraint forces were also investigated. Crack widths from NLFE simulations were then compared with corresponding results calculated using linear FEA results as input for design equations given in EN 1992-1-1. The latter resulted in estimated cracks more than 10 times wider than that obtained in the simulations, while crack widths predicted using the EN 1992-3 approach showed better correspondence to the NLFE results.
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26

Brisebois, Philippe. "Combination of thermal and seismic displacements for the design of base isolation systems of bridges in Canada." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107718.

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Base isolation systems are commonly used in the design of new bridges, and in the retrofit of existing ones. However, in Canada, base isolators are relatively new. They act as bridge bearings and isolate or decouple the superstructure from the underlying substructure to reduce the force generated in the structure by ground-motions. Horizontal displacements of isolators due to thermal and seismic loads are addressed in the Canadian Highway Bridge Design Code (CHBDC) CSA-S6-06 and adequate clearance must be provided. However, the Canadian code does not offer any guidance on how to combine these displacements. The objective of this thesis is to present the calculation methods of these displacements and to suggest different ways to combine them. Two bridges are analyzed in this thesis under Montreal's and Vancouver's thermal and seismic provisions to define a proposed thermal and seismic displacement combination formula for the design of base isolators in bridges in Canada.
Les isolateurs sismiques sont utilisés de plus en plus couramment pour la conception des nouveaux ponts ou pour la réfection des ponts existants. Or, ces isolateurs sont relativement nouveaux au Canada. En général, ils protègent la structure du pont en découplant le mouvement du sol du mouvement de la structure et en augmentant la période de vibration afin de réduire les accélérations transmises à la structure. Ces appuis sont conçus pour des déplacements admissibles spécifiés. La norme canadienne des ponts (CSA-S6) adresse les déplacements sismiques et thermiques, mais n'offre aucune directive sur la combinaison de ces déplacements. L'objectif de ma thèse est de présenter les méthodes de calcul pour ces déplacements et de suggérer diverses approches pour faire la combinaison des déplacements. Les ponts de Madrid et de l'autoroute 30 au-dessus du fleuve St-Laurent sont analysés sous les charges sismiques et thermiques de Montréal et Vancouver pour établir une combinaison optimale des déplacements sismiques et thermiques des isolateurs sismiques des ponts au Canada.
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27

Garapati, Sriharsha. "Analytical and Numerical Modeling of Assembly Procedures of Steel Fulcra of Bascule Bridges." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4490.

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To model shrink-fitting in metal components, an analytical model for two long compound cylinders with temperature dependent material properties and interference between them is developed for calculating transient temperatures and stresses. A finite element model is developed for the same geometry which incorporated the temperature dependent material properties. A convergence study is performed on the finite element and analytical model. The finite element model is validated by comparing the approximations of finite element model with the analytical solution. In an assembly procedure of fulcrums for bascule bridges, called AP1, the trunnion is shrink-fitted into a hub, followed by shrink fitting the trunnion-hub assembly into the girder of the bridge. In another assembly procedure called AP2, the hub is shrink-fitted into the girder, followed by shrink-fitting the trunnion in the hub-girder assembly. A formal design of experiments (DOE) study is conducted on both AP1 and AP2 using the finite element model to find the influence of geometrical parameters such as radial thickness of the hub, radial interference, and various shrink-fitting methods on the design parameter of overall minimum critical crack length (OMCCL) - a measure of likelihood of failure by cracking. Using the results of DOE study conducted on both the assembly procedures, AP1 and AP2 are quantitatively compared for the likelihood of fracture during assembly. For single-staged shrink-fitting methods, for high and low hub radial thickness to hub inner diameter ratio, assembly procedure AP1 and AP2 are recommended, respectively. For fulcra with low hub radial thickness to hub inner diameter ratio and where staged shrink-fitting methods are used, for AP2, cooling the trunnion in dry-ice/alcohol and heating the girder, and for AP1, cooling the trunnion-hub assembly in dry-ice/alcohol followed by immersion in liquid nitrogen is recommended. For fulcra with high hub radial thickness to hub inner diameter ratio and where staged shrink-fitting methods are used, cooling the components in dry-ice/alcohol and heating the girder is recommended for both AP1 and AP2. Due to the limitations of AP2, assembly procedures by heating the girder with heating coils instead of dipping an already stressed trunnion-hub assembly in liquid nitrogen are studied for decreasing the likelihood of failure by cracking and yielding. In an assembly procedure called AP3-A, only the girder is heated to shrink-fit the trunnion-hub assembly in the girder. This assembly procedure AP3-A is found to be infeasible because the girder fails by yielding if heating is expected to be completed in a reasonable amount of time. An alternative assembly procedure called AP3-B is suggested for shrink-fitting where the heating of the girder is combined with cooling the trunnion-hub assembly in dry-ice/alcohol mixture. This assembly procedure AP3-B is found to be feasible. A complete DOE study is conducted on AP3-B to find the influence of parameters like hub radial thickness and radial interference at trunnion-hub interface on the design parameter of overall minimum critical crack length. The design parameter, OMCCL values during the assembly procedure AP3-B are quantitatively compared with the widely used assembly procedures (AP1 single-stage shrink-fitting and AP1 multi-staged shrink fitting). The results of this work suggest that increasing the hub radial thickness decreases the likelihood of fracture significantly. For hubs with large radial thickness, heating the girder combined with cooling the trunnion-hub in dry-ice/alcohol mixture (AP3-B) is recommended but for hubs with low radial thickness, multistage cooling of the trunnion-hub assembly in dry-ice/alcohol mixture followed by dipping in liquid nitrogen (AP1- multistage cooling) is recommended.
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28

Paul, Jai P. "Sensitivity analysis of design parameters for trunnion-hub assemblies of bascule bridges using finite element methods." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001157.

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29

Ahlgren, Tobias, and Jalal Eliassi. "Värmeförluster vid utvändigt placerade ventilationssystem." Thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-20676.

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To be able to handle tomorrows need for limited energy consumption we need to reduce our use of energy. The building sector stands for around 40 % of all energy consumption in the society. The government has put up a goal to reduce the energy consumption in our buildings with 20 % by year 2020 and 50 % by year 2050 compared with year 1995. To be able to do reach that goal we need a more energy efficient building stock. The main part of the energy used in our buildings is used for space heating. By installing ventilation systems with heat recovery on the exhaust air it is possible to use the heat-energy in the exhaust air to warm up the incoming air. This can contribute to a reduction in energy use. A ventilation system with heat recovery on the exhaust air is space demanding and there can be problems with finding enough space to do the installation indoors. Therefore it can be an advantage to place the aggregate and the ducts on the outside of the buildings climate shell. A placement exterior of the buildings climate shell or in an unheated space leads to thermal heat losses. The aim with this essay is to investigate how significant the heat losses are on exterior placed ventilation systems. The investigation has been done with help of theoretical calculations and measurements of the temperature difference in the ventilation ducts. Analysis has been made on life cycle costs on how to reduce the heat losses in an economic manner. To buildings, Höstvägen 14 and 22 in Växjö, which have been equipped with exterior placed ventilation systems have been studied. The two buildings have two different types of installation of the ducts. Our result shows that the heat losses through the ventilation systems on Höstvägen 14 and 22 are significant. The majority of the losses occur in the ducts. In the aggregate the thermal bridges in the framework accounts for the larger part.
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30

Lee, Jonghang. "Experimental and analytical investigations of the thermal behavior of prestressed concrete bridge girders including imperfections." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34675.

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An experimental and analytical study was conducted on a BT-63 prestressed concrete girder to investigate the thermal effects on the girder. A 2D finite element heat transfer analysis model was then developed which accounted for heat conduction, convection, radiation, and irradiation. The solar radiation was predicted using the location and geometry of the girder, variations in the solar position, and the shadow from the top flange on other girder surfaces. The girder temperatures obtained from the 2D heat transfer analysis matched well with the measurements. Using the temperatures from the 2D heat transfer analysis, a 3D solid finite element analysis was performed assuming the temperatures constant along the length of the girder. The maximum vertical displacement due to measured environmental conditions was found to be 0.29 inches and the maximum lateral displacement was found to be 0.57 inches. Using the proposed numerical approach, extremes in thermal effects including seasonal variations and bridge orientations were investigated around the United States to propose vertical and transverse thermal gradients which could then be used in the design of I-shaped prestressed concrete bridge girders. A simple beam model was developed to calculate the vertical and lateral thermal deformations which were shown to be within 6% of the 3D finite element analyses results. Finally, equations were developed to predict the maximum thermal vertical and lateral displacements for four AASHTO-PCI standard girders. To analyze the combined effects of thermal response, initial sweep, and bearing support slope on a 100-foot long BT-63 prestressed concrete girder, a 3D finite element sequential analysis procedure was developed which accounted for the changes in the geometry and stress state of the girder in each construction stage. The final construction stage then exposed the girder to thermal effects and performed a geometric nonlinear analysis which also considered the nonlinear behavior of the elastomeric bearing pads. This solution detected an instability under the following conditions: support slope of 5¡Æ and initial sweep of 4.5 inches.
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Semendary, Ali A. "Behavior of Adjacent Prestressed Concrete Box Beam Bridges Containing Ultra High Performance Concrete (UHPC) Longitudinal Joints." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1518181442348314.

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32

Skoglund, Erika, and Max Flemström. "Trä- och stålreglars påverkan av värmeflödet i utfackningsväggar." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-23708.

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Inom dagens byggande i Sverige ställs allt högre krav på den värmeisolerande förmågan hos klimatskärmen i de hus som byggs. Detta ställer i sin tur högre krav på konstruktionerna och medför även ny problematik. Standardlösningar som tidigare fungerat bra byts ut mot nya, ibland obeprövade, lösningar. De hårdare kraven på energi- och fuktdimensionering innebär alltså att vikten av val av stommaterial ökar vid en projektering. Vi har här försökt ge en realistisk bild av hur valet av reglar kan påverka energi och fukttillståndet hos en byggnad med utfackningsväggar, med fokus på reglar i fält. Till undersökningen användes referensobjekt i form av ritningar som tillhandahölls av handledaren på Clarus arkitekter. Med hjälp av dessa gjordes tredimensionella energiberäkningar som visade dels att valet av material kan ha mycket stor betydelse både för energiförluster och fukttillstånd, samt att sambanden inte nödvändigtvis behöver vara enkla. Valet av reglar har mycket varierande betydelse beroende på hur väggen är uppbyggd. Genom en laboration undersöktes skillnaden mellan slitsade och oslitsade ytterväggsreglar för att ge ökad förståelse och verifiera noggrannheten av beräkningarna jämfört med en verklig vägg. Det sista visade sig svårt att uppnå, men det var tydligt att slitsarna hade mycket stor betydelse för temperaturfördelningen i en vägg.
Construction of Swedish buildings today places higher demands on the heat-insulating capacity of the building envelope in the house built. This in turn places higher demands on the structures and also creates new problems. Standard solutions that previously worked well are being replaced by new, sometimes untested, solutions. The tougher demands on energy and moisture design means that the choice of substrate material is of greater importance than before when designing buildings.Here we have tried to give a realistic view of how the choice of studs can affect energy and humidity conditions of a building with curtain walls, focusing on studs in the field. The survey used reference objects projects in the form of drawings provided by the supervisor at Clarus Architects. Using these, three-dimensional calculations were made showing firstly that the choice of material can be of great importance both for the energy and moisture, and secondly, that the relationship is not necessarily simple. The importance of the choice of studs varies depending on how the wall is built. By a laboratory experiment, the correlation between slotted and unslotted outer wall studs was examined to provide greater understanding and verifying the accuracy of the calculations compared to a real wall. The last task proved difficult to achieve, but it was clear that the studs had great significance for the temperature distribution in a wall.
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33

Öberg, Andreas. "Nytt Värmesystem till en skola : Beräkning av transmissions- och ventilationsförluster." Thesis, Mittuniversitetet, Institutionen för kemiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39316.

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Med hjälp av Boverkets byggregler och de ISO-standarder som föreskrivs fastställs värmeeffektbehovet för Kyrkbackskolan, Ljusnarsbergs kommunala skola. Ur effektbehovet har sedan ett teoretiskt värmesystem dimensionerats. Resultaten visar att de olika byggnaderna som skolan består av har olika behov beroende på deras utformning. Över trehundra radiatorer och över trehundrafyrtio kilowatt värmeeffekt behövs för att värma skolan enligt de utförda beräkningarna för transmissionsförluster, ventilationsförluster och köldbryggor. Den största osäkerheten finns i köldbryggorna då dessa är baserade på tabellvärden. En rumslista visar vad varje rum i hela skolan har för effektbehov och kan användas vid både installation och injustering.
Using ”Boverkets byggregler” and the ISO-standards that are stipulated in it are the heating requirements determined for “Kyrkbackskolan”, the only school in the municipality of Ljusnarsberg. A theoretical heating system has been designed based on the calculations. The results show that the three different buildings that make up the school have different requirements depending on their layout. Over three hundred radiators and over three hundred forty kilowatts of heating power are required to heat the school according to the calculations of transmission losses, ventilation losses and thermal bridges. The largest insecurity is in the thermal bridges since they are determined using tables. A list shows all the rooms and their heating requirements which can be used when installing or tuning the heating system.
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Šagát, Hynek. "Diagnostika a návrh eliminace tepelných mostů budovy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240326.

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This thesis deals with the temperature-moisture assessment of builgind constructions apartment building. Selected critical details are examined in special programs Area 2015 and Cube3D 2015. The thesis also includes thermal measurement of apartment building using a termovision camera. Theoretical calculations are then compared with measurements which were performed on a real building.
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35

Karlsson, Fredrik, and Samuel Mani. "Beräkning och sammanställning av linjära köldbryggor : En jämförelse mellan HEAT2 och COMSOL Multiphysics." Thesis, KTH, Byggvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174115.

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I dagens samhälle ligger stort fokus på att bygga miljövänliga och energieffektiva byggnader. För att möta de allt mer skärpta energikraven måste hela klimatskalet beaktas där köldbryggor utgör en betydande del. Examensarbetet går ut på att göra en sammanställning av linjära köldbryggor (ψ) för vanligt förekommande konstruktionsdetaljer där köldbryggor finns. Sammanställningen där olika isoleringsmaterial på fasadskiva och isolertjocklekar tabelleras, ska underlätta för framtida projektering. Två simuleringsprogram för beräkning av köldbryggor har jämförts och utvärderats med varandra. Utvärderingen har gjorts med avseende på vilket program som var mest lämpat för att lösa frågeställningen. De två simuleringsprogrammen som används vid detta arbete är HEAT2 och COMSOL Multiphysics. Arbetet har resulterat i en lathund som finns tillgänglig på ELU:s intranät. Lathunden innehåller U-värde och ψ-värde med illustrering av konstruktionsdetaljerna och i detta arbete redovisas tillvägagångssätt och utförandet. En utvärdering av det lämpligaste program för utförandet av uppgiften finns också redovisad.
Currently there is a lot of focus on environmentally friendly and energy efficient buildings in our society. To face the more toughen energy requirements, the entire climate shell of the building has to be considered there thermal bridges constitute a significant part. This bachelor dissertation intends to create a compilation for Ψ-values of common construction details where thermal bridges are to be found. The compilation with a chart that includes insulating material and insulation thickness shall simplify in future projecting. Furthermore, two simulating programs for calculations of thermal bridges have been compared with each other. The two simulation programs that have been used in this dissertation are HEAT2 and COMSOL Multiphysics. This dissertation has resulted in a quick reference guide which is available at ELU`s internal network. This quick reference guide includes U-values and Ψ-values with an illustration of every construction detail and the procedure and execution is reported in this dissertation. An evaluation of which of the two programs that has been used was more appropriate for this purpose is presented as well.
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36

Carlsson, Linus, and David Liljenberg. "Anpassning av timmerhus enligt nya energikrav i BBR 29 : Glass House Villa 126." Thesis, KTH, Byggteknik och design, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302481.

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Den 1 september 2020 trädde den konsoliderade versionen av Boverkets Byggregler BBR 29 i kraft. En stor del av skillnaden från föregående version var det ökade kravet på energihushållning. Det nya kravet som fastställts innebär att U-medelvärdet är sänkt från 0,4 W/m2K till 0,3 W/m2K. Detta är ett mått på hur väl en byggnad är isolerad. Företaget Kontio expanderade till Sverige från Finland för snart fyra år sedan. De säljer framförallt fritidsboende och småhus byggda av egentillverkade timmerstockar med korslimmad arktisk furu i olika dimensioner. Deras hus säljs på den finska marknaden, men i Sverige har endast vissa timmerdimensioner klarat det gamla kravet från BBR 28. Med det nya kravet måste klimatskärmen anpassas till den nya kravbilden. Tak och golv är färdigprojekterade med låga U-värden, därför finns den största möjligheten för anpassning i väggkonstruktionerna. Med hjälp av givna förutsättningar togs ett antal väggkonstruktioner fram för beräkning av U-värdet. Dessa gav upphov till olika typlösningar som varierar med, förutom väggkonstruktionen, fönstertyper och minskade fönsterareor. Framräknat U-värde för väggkonstruktion låg till grund för beräkning av U-medelvärde tillsammans med U-värde för fönster, golv och tak. Ändringar i väggkonstruktioner kan resultera i en förekomst av fuktproblem. Därför testas dessa med hjälp av en Glaser-tabell som undersöker genom stationära beräkningar huruvida det föreligger någon risk i framtagna väggkonstruktioner. Detta projekt analyserar även för- och nackdelar med timmer i furu och dess värmelagrande funktion som beror på en hög värmekapacitet. Med utgångspunkt i litteraturstudien analyseras och utreds var i konstruktionen man med störst fördel placerar den massiva timmerstrukturen i förhållande till värmeisolering. Alla väggkonstruktioner behövde göras om utom 275 där endast fönstertyp ändrades till de med lägre U-värde. Vid anpassning av väggkonstruktioner med timmerdimension 135 och 205 krävdes mer omfattande åtgärder. Genom att isolera väggarna, ändra fönstertyper och minska fönsterareor kunde kravet på U-medelvärde nås på olika sätt. Ingen av dessa vägguppbyggnader uppvisade tecken på fukttekniska problem.
On September 1, 2020, the consolidated version of the National Board of Housing, Building and Planning's Building Rules BBR 29 took effect. A large part of the difference from the previous version was the increased demand for energy management. The new requirement that has been established means that the mean U-value has been reduced from 0.4 W/m2K to 0.3 W/m2K. This is a measurement of how well a building is insulated. Almost four years ago, the company Kontio expanded to Sweden from Finland. They mainly sell holiday homes and living houses built from self-made logs with cross-laminated arctic pine in various dimensions. Their houses are sold on the Finnish market, but in Sweden only certain timber dimensions have met the old requirement from BBR 28. With the new BBR 29, the building shell must be adapted to the new requirement. Ceilings and floors are pre-designed with low U-values and for this reason further improvements are best made in the wall construction. Using the given conditions, a number of wall constructions were developed for calculating the U-value. These gave rise to different type solutions that vary with, in addition to the wall construction, window types and reduced window areas. Calculated U-value for wall construction was the basis for calculating the mean U-value together with the U-value for windows, floors and ceilings. Changes in wall constructions can result in the occurrence of moisture problems, therefore these walls are tested using a Glaser-table which examines, by stationary calculations, whether there is any risk in the adapted constructions. This project also analyzes the advantages and disadvantages of pine timber and its heat storage function due to its high heat capacity. Based on the literature study, it is analyzed and investigated where in the construction the massive timber structure is placed with the greatest advantage in relation to the thermal insulation. All wall constructions needed to be adapted except 275 where only the window type was changed to those with a lower U-value. When adapting wall constructions with timber dimensions 135 and 205, more extensive measures were required. By insulating the walls, changing window types and reducing window areas, the requirement for the mean U-value could be achieved in various ways. None of these wall constructions showed signs of moisture technical problems.
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37

Kabzáni, Matej. "Vplyv energetických opatrní na ceny prevádzky budovy." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318594.

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The theme of the diploma thesis "Effect of energy care on building prices" is the design and assessment of several measures, two of which generally lead to lower heating costs. The diploma thesis deals with evaluation of the current state of the family house and determination of PENB before the construction modifications and subsequently after the construction modifications, defining subsequent measures for energy saving implementation, both in terms of energy, economic and also environmental.
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38

Chamoun, Ronney, and Salahadin Husseini. "Köldbryggors inverkan på isoleringsegenskaper för sandwichelement : Anslutning mellan fönster och yttervägg." Thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-11258.

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I dagens läge har energifrågorna väckt ett stort intresse i samhället. Nu fokuseras det mer på att bygga energisnålare hus. En betydande faktor som påverkar energiförbrukningen i våra hus är köldbryggor. De uppstår då ett material med dålig värmeisolering bryter igenom ett material med bättre värmeisolering. Köldbryggor är nästan omöjligt att undvika, dock går alltid att reducera. I praktiken är det ofta inte möjligt att helt undvika köldbryggor, men det finns många olika möjligheter att minska köldbryggeffekten kraftigt. Detta eftersträvas för att uppnå lägre energikostnader eftersom köldbryggor kan medföra en betydande ökning av värmeförlusten. Avgränsningen för detta examensarbete framgår av titeln Köldbryggors inverkan på isoleringsegenskaper för sandwichelement, anslutning mellan fönster och yttervägg. Den främsta metoden som används för att åstadkomma resultatet är PC-programmet HEAT2, men litteraturstudier har också använts. HEAT2 är ett tvådimensionellt värmeflödesprogram, som beräknar den värmemängd som leds genom konstruktionsdelen. Den bygger på att dela in byggnadsdelen i ett rutnät (mesh). Ju fler rutor den blir uppdelad i, desto noggrannare resultat, men beräkningen blir samtidigt mer tidskrävande att utföra. En särskild analys gjordes med och utan den dränerande skyddsplasten i fönstrets överkant då materialet skär igenom värmeisoleringen vid betongklacken. Plasten har mångfaldigt högre värmekonduktivitet än värmeisoleringen, men den är bara 1 mm tjock. Beräkningsresultaten visar att skyddsplasten gav en betydande skillnad.
Currently, the energy issues brought a lot of interest in the community. Now is the focus more on building energy-efficient houses. A significant factor influencing energy consumption in our buildings is thermal bridges. They occur when a material with poor thermal insulation breaks through a material with better insulation. In practice it is often not possible to avoid thermal bridges completely, but there are many different options to reduce the thermal bridge effect significantly. This is desirable in order to achieve lower energy costs because thermal bridges can lead to a significant increase in the heat losses. The limitation of this degree project is evident from the title Thermal bridges impact on the insulation properties of sandwich panels, the connection between the windows and external walls The primary means used to achieve the results is the HEAT2 PC-program, but literature studies were also used. HEAT2 is a two-dimensional heat flow program that calculates the amount of energy passed through the part of the construction. It is based on the allocation of the construction into a mesh, i.e. a grid. The more the mesh is divided into the more accurate the results, but the calculations are at the same time more time consuming to perform. A separate analysis was done with and without the draining protective plastic in the window's top edge where the material is passing through the thermal insulation at the concrete heel. The plastic has many orders of magnitude higher thermal conductivity than the thermal insulation, but it is only 1 mm thick. The calculation results show that the plastic caused a significant difference.
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39

Baďurová, Monika. "Vliv obálkových konstrukcí budovy na výdaje spojené s jejím provozem." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241339.

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The thesis deals with the assessment of the current proposal for pension envelopes along with proposing alternative plans with emphasis on reducing heating costs. The first section describes the types of buildings according to heating demand and output energy performance of buildings. Work also deals with a list of different variants of thermal insulation materials and design options outer insulation of the building envelope. It outlines fire characteristics of building materials and options of construction budget. The second part is devoted to a specific pension house in the Old Rejviz for which there are designed in three variants of insulation. These variants are then reviewed in terms of thermal insulation. Through research will bedetermined price of implementation of proposed insulation options together with the costs of operation of the pension. The conclusion is to evaluate each proposed version of insulation of the building envelope associated with the economic return on investment.
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40

Karami, Peyman. "Robust and Durable Vacuum Insulation Technology for Buildings." Doctoral thesis, KTH, Byggnadsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176494.

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Today’s buildings are responsible for 40% of the world’s energy use and also a substantial share of the Global Warming Potential (GWP). In Sweden, about 21% of the energy use can be related to the heat losses through the climatic envelope. The “Million Program” (Swedish: Miljonprogrammet) is a common name for about one million housing units, erected between 1965 and 1974 and many of these buildings suffer from poor energy performance. An important aim of this study was to access the possibilities of using Vacuum Insulation Panels (VIPs) in buildings with emphasis on the use of VIPs for improving the thermal efficiency of the “Million Program” buildings. The VIPs have a thermal resistance of about 8-10 times better than conventional insulations and offer unique opportunities to reduce the thickness of the thermal insulation. This thesis is divided into three main subjects. The first subject aims to investigate new alternative VIP cores that may reduce the market price of VIPs. Three newly developed nanoporous silica were tested using different steady-state and transient methods. A new self-designed device, connected to a Transient Plane Source (TPS) instrument was used to determine the thermal conductivity of granular powders at different gaseous pressure combined with different mechanical loads. The conclusion was that the TPS technique is less suitable for conducting thermal conductivity measurements on low-density nanoporous silica powders. However, deviations in the results are minimal for densities above a limit at which the pure conduction becomes dominant compared to heat transfer by radiation. The second subject of this work was to propose a new and robust VIP mounting system, with minimized thermal bridges, for improving the thermal efficiency of the “Million Program” buildings. On the basis of the parametric analysis and dynamic simulations, a new VIP mounting system was proposed and evaluated through full scale measurements in a climatic chamber. The in situ measurements showed that the suggested new VIP technical solution, consisting of 20mm thick VIPs, can improve the thermal transmittance of the wall, up to a level of 56%. An improved thermal transmittance of the wall at centre-of-panel coordinate of 0.118 to 0.132 W m-2K-1 and a measured centre-of-panel thermal conductivity (λcentre-of-panel) of 7 mW m-1K-1 were reached. Furthermore, this thesis includes a new approach to measure the thermal bridge impacts due to the VIP joints and laminates, through conducting infrared thermography investigations. An effective thermal conductivity of 10.9 mW m-1K-1 was measured. The higher measured centre-of-panel and effective thermal conductivities than the published centre-of-panel thermal conductivity of 4.2 mW m-1K-1 from the VIP manufacturer, suggest that the real thermal performance of VIPs, when are mounted in construction, is comparatively worse than of the measured performance in the laboratory. An effective thermal conductivity of 10.9 mW m-1K-1 will, however, provide an excellent thermal performance to the construction. The third subject of this thesis aims to assess the environmental impacts of production and operation of VIP-insulated buildings, since there is a lack of life cycle analysis of whole buildings with vacuum panels. It was concluded that VIPs have a greater environmental impact than conventional insulation, in all categories except Ozone Depilation Potential. The VIPs have a measurable influence on the total Global Warming Potential and Primary Energy use of the buildings when both production and operation are taken into account. However, the environmental effect of using VIPs is positive when compared to the GWP of a standard building (a reduction of 6%) while the PE is increased by 20%. It was concluded that further promotion of VIPs will benefit from reduced energy use or alternative energy sources in the production of VIP cores while the use of alternative cores and recycling of VIP cores may also help reduce the environmental impact. Also, a sensitivity analysis of this study showed that the choice of VIPs has a significant effect on the environmental impacts, allowing for a reduction of the total PE of a building by 12% and the GWP can be reduced as much as 11% when considering both production and operation of 50 yes. Finally, it’s possible to conclude that the VIPs are very competitive alternative for insulating buildings from the Swedish “Million Program”. Nevertheless, further investigations require for minimizing the measurable environmental impacts that acquired in this LCA study for the VIP-insulated buildings.
Dagens byggnader ansvarar för omkring 40% av världens energianvändning och  står också för en väsentlig del av utsläppen av växthusgaser. I Sverige kan ca 21 % av energianvändningen relateras till förluster genom klimatskalet. Miljonprogrammet är ett namn för omkring en miljon bostäder som byggdes mellan 1965 och 1974, och många av dessa byggnader har en dålig energiprestanda efter dagens mått. Huvudsyftet med denna studie har varit att utforska möjligheterna att använda vakuumisoleringspaneler (VIP:ar) i byggnader med viss fokus på tillämpning i Miljonprogrammets byggnader. Med en värmeledningsförmåga som är ca 8 - 10 gånger bättre än för traditionell isolering erbjuder VIP:arna unika möjligheter till förbättrad termisk prestanda med minimal isolerings tjocklek. Denna avhandling hade tre huvudsyften. Det första var att undersöka nya alternativ för kärnmaterial som bland annat kan reducera kostnaden vid produktion av VIP:ar. Tre nyutvecklade nanoporösa kiselpulver har testats med olika stationära och transienta metoder. En inom projektet utvecklad testbädd som kan anslutas till TPS instrument (Transient Plane Source sensor), har använts för att mäta värmeledningsförmågan hos kärnmaterial för VIP:ar, vid varierande gastryck och olika mekaniska laster. Slutsatsen blev att transienta metoder är mindre lämpliga för utföra mätningar av värmeledningsförmåga för nanoporösa kiselpulver låg densitet. Avvikelsen i resultaten är dock minimal för densiteter ovan en gräns då värmeledningen genom fasta material blir dominerande jämfört med värmeöverföring genom strålning. Det andra syftet har varit att föreslå ett nytt monteringssystem för VIP:ar som kan användas för att förbättra energieffektiviteten i byggnader som är typiska för Miljonprogrammet. Genom parametrisk analys och dynamiska simuleringar har vi kommit fram till ett förslag på ett nytt monteringssystem för VIP:ar som har utvärderats genom fullskaleförsök i klimatkammare. Resultaten från fullskaleförsöken visar att den nya tekniska lösningen förbättrar väggens U-värde med upp till 56 %. En förbättrad värmegenomgångskoefficienten för väggen i mitten av en VIP blev mellan 0.118 till 0,132 W m-2K-1 och värmeledningstalet centre-av-panel 7 mW m-1K-1 uppnåddes. Detta arbete innehåller dessutom en ny metod för att mäta köldbryggor i anslutningar med hjälp av infraröd termografi. En effektiv värmeledningsförmåga för 10.9 mW m-1K-1 uppnåddes. Resultaten tyder även på att den verkliga termiska prestandan av VIP:ar i konstruktioner är något sämre än mätvärden för paneler i laboratorium. En effektiv värmeledningsförmåga av 10.9 mW m-1K-1 ger dock väggkonstruktionen en utmärkt termisk prestanda. Det tredje syftet har varit att bedöma miljöpåverkan av en VIP-isolerad byggnad, från produktion till drift, eftersom en livscykelanalys av hela byggnader som är isolerade med vakuumisoleringspaneler inte har gjorts tidigare. Slutsatsen var att VIP:ar har en större miljöpåverkan än traditionell isolering, i alla kategorier förutom ozonnedbrytande potential. VIP:ar har en mätbar påverkan på de totala utsläppen av växthusgaser och primärenergianvändningen i byggnader när både produktion och drift beaktas. Miljöpåverkan av de använda VIP:arna är dock positiv jämfört med GWP av en standardbyggnad (en minskning med 6 %) medan primärenergianvändningen ökade med 20 %. Slutsatsen var att ytterligare användning av VIP:ar gynnas av reducerad energiförbrukning och alternativa energikällor i produktionen av nanoporösa kiselpulver medan användningen av alternativa kärnmaterial och återvinning av VIP kärnor kan hjälpa till att minska miljöpåverkan. En känslighetsanalys visade att valet av VIP:ar har en betydande inverkan på miljöpåverkan, vilket ger möjlighet att reducera den totala användningen av primärenergi i en byggnad med 12 % och utsläppen av växthusgaser kan vara minska, så mycket som 11 % när det gäller både produktion och drift under 50 år. Avslutningsvis är det möjligt att dra slutsatsen att VIP:ar är ett mycket konkurrenskraftigt alternativ för att isolera byggnader som är typiska för Miljonprogrammet. Dock krävs ytterligare undersökningar för att minimera de mätbara miljöeffekter som förvärvats i denna LCA-studie för VIP-isolerade byggnader.

QC 20151109


Simulations of heat and moisture conditions in a retrofit wall construction with Vacuum Insulation Panels
Textural and thermal conductivity properties of a low density mesoporous silica material
A study of the thermal conductivity of granular silica materials for VIPs at different levels of gaseous pressure and external loads
Evaluation of the thermal conductivity of a new nanoporous silica material for VIPs – trends of thermal conductivity versus density
A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels
ETICS with VIPs for improving buildings from the Swedish million unit program “Miljonprogrammet”
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41

Kulasin, Aid. "Isolerande balkonginfästningar : Thermally-insulated balconies." Thesis, Växjö universitet, Institutionen för teknik och design, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-2493.

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In this work a study has been performed to show the different kinds of insulated balcony connections exists on the market. In the work there is also a short description of thermal bridges concerning balconies. A description of older solutions for balcony connections is given as well as a calculation of the difference in energy costs for a insulated balcony connection compared to the standard connection. The work includes a short description of the different products. After that there is a short information about their insulation properties, durability, acoustic performance, assembly, computer programme and a short analyses for each product.
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42

Zvonek, Lukáš. "Vliv provedení zateplení bytového domu ve Slavičíně na výdaje spojené s jeho provozem." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-402648.

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The aim of the thesis is the economic evaluation of return of the different variants of thermal insulation for residential building in Slavičín. In the first part are described the topics, which is related to the issue. Further, it is written the entire range of insulations, which currently are appear on the domestic market. In the practical part is described the residential house and are performed by the proposals of the variants of thermal insulation. Further, they are processed energy performance certificates for buildings, the cost to implement the options chosen. In conclusion, the evaluated individual variants and determined their economic return.
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43

Furenstam, Kasper. "Monitoring and Modelling of the Abiskojåkka Bridge." Thesis, Luleå tekniska universitet, Byggkonstruktion och brand, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79118.

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The infrastructure of today is getting older and problems caused by deterioration over time is affecting the service life of these structures. In Sweden most of the existing bridges were constructed 60 to 70 years ago, rising the need to determine the state of health of the bridges as the maintenance costs will increase heavily. Part of the above-mentioned cut of the bridges owned by Trafikverket (The Swedish Transport Administration) that was constructed 60 – 70 years ago are pre-stressed concrete bridges. Pre-stressing of concrete structures is today a commonly used technology that utilizes the beneficial characteristic of concrete, the compressive strength, to a further extent than reinforced concrete.     This report will focus on the problems with pre-stressed concrete bridges and particularly on the thermal effects on the Abiskojokk railway bridge located in the northern part of Sweden. The pre-stressed box girder bridge spans in total 86 m in three lengths of 30 m, 35 m respectively 21 m starting from the east abutment and is part of the Iron-Ore Line starting in Kiruna and ending in Narvik, Norway. In an ocular(särskild) inspection of the bridge carried out the 18th of August in 2016 several crack patterns were mapped on the inside of the box girder along with some cracks about the top of the first column support starting from the east abutment. This thesis is focusing on the cracks that was mapped along the tendon positions on the inside of the box girder in the first span starting from the east abutment. The hypothesis is that the cracks are caused by temperature loads and normal forces obtained from the tendons at the thickening of the cross-sections. The research questions are; what the monitoring program shows and if it is possible to prove the hypothesis by using of a FE-model considering the gravity loads, temperature loads and the pre-stressing.     In order to determine the cause of the cracks on the inside of the box girder and investigate the behaviour of the bridge a monitoring program was installed, measuring the crack development over time along with the acceleration and temperatures of the bridge. Example data from the program were later used to analyse the behaviour of the bridge.     The results from the temperature data shows that the bridge has a slowness to temperature changes outside. This gives rise to temperature gradient acting over the bridge parts that may contribute to crack propagation. It also showed that the temperature correlates well with the strain of the cracks. The LVDT’s showed that the largest crack openings during train loading occurred in the second span of the bridge. The data also showed relatively large and unexpected negative peaks during the train loads. The strain gauges also show that the largest strain is occurring in the second span of the bridge. The crack envelopment during a train loads are more expected here and may prove that the negative peaks from the LVDT’s and accelerometers are caused by vibrations. The accelerometers showed that the largest transversal accelerations take place in the first and third span. This may be due to more restricted supports conditions at the column supports than the abutments. The accelerometer also showed correlating negative peaks with the LVDT’s that may be caused by vibrations in the bridge.     The conclusion from the monitoring program so far is that is not possible to prove the cause of the cracks so far, but it may be in the future.     The results from the non-linear FE-model showed that the thermal action of the Eurocode gradient was not enough to crack the concrete along with the pre-stressing load. However, the effects of the hypothesis were proven right.
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44

Emili, Antonella. "Assessing the Thermal Performance of Glazed Curtain Wall Systems : S+G Project Case Study." Thesis, KTH, Installations- och energisystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-164956.

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The improvement of curtain wall thermal performances and the optimisation of the issues connected with this technology can lead to a sensible reduction of the energy consumption of the building as well as to an increase level of occupant comfort and longer durability of the façade. The aim of this work is to improve the curtain wall technology especially as far as the connection between the glass and the frame is concerned, since it is the part that mainly affects the performances of the whole façade. This project focuses on the different aspects of the thermal performance of curtain wall systems in order to achieve a higher thermal performance, meeting the objectives of lowering energy demand, improving durability and enhancing indoor comfort. In order to develop new high performance curtain wall connections and to test their level of performance compared with the state of the art ones, two methods were deployed: a numerical and an experimental one. FEM analysis was performed with the software THERM (LBNL) analysing the profile of surface temperatures and the U-values of the details. In the FEM analysis, different materials and geometries were studied. The experimental characterisation of the thermal energy performance of the studied design options was performed by means of thermometric measurements in a climatic cell. The purpose of the experimental analysis was the verification of the effective improvement of the performance in the new details and the comparison with the simulation, aiming at the validation of the simulation model.
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45

Fauley, Stacey Marie. "Selected Synthetic Studies of NLO pi-Bridges and Thermally Stable Monomers." Wright State University / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=wright1033146948.

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46

Itoh, Yoshito, Haosheng Gu, Kazuya Satoh, and Yoshihisa Yamamoto. "Long-term Deterioration of High Damping Rubber Bridge Bearing." 土木学会, 2006. http://hdl.handle.net/2237/7459.

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47

Forman, Daniel. "Základní škola." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226178.

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Thesis Theme is a primary school, namely the outbuilding primary school Havlíčkův Brod, Konečná 1884. I suggest first grade pavilion and pavilion with school canteen with kitchens. Pavilions are based on the footings. Pavilions are designed as a two-way system from the wall HELUZ. Construction of ceiling are from ferroconcrete slabs are cross reinforced, single-layer roof is flat with a classic sequence of layers. In addition to construction and process layout I solved also the statics of building in specialize of concrete structures. The following are also evaluated heat and acoustic requirements and requirements for fire safety of buildings. New pavilions are solved as wheelchair accessible. Pavilion of the first grade has two floors with 5 classes of stem, 1 vocational and 2 classes are earmarked for after-school clubs. This pavilion is connected to the connecting neck between the former pavilon A and pavilion B. Dining pavilion has one floor, which is divided in the school canteen and kitchen is connected to the connecting neck leading to the gym. The land is mildly sloping to the south side. All consstructions comply with the applicable standards and recommendations ČSN.
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48

Dahiya, Ankuj. "Long-Term Monitoring and Evaluation of the Varina-Enon Bridge." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/102891.

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To make sound decisions about the remaining life of a structure, the precise calculation of the prestress losses is very important. In post-tensioned structures, the prestress losses due to creep and shrinkage can cause serviceability issues and can reduce flexural capacity. The Varina-Enon Bridge is a cable-stayed, precast, segmental, post-tensioned box girder bridge located in Richmond, Virginia. Observation of flexural cracks in the bridge by inspectors promoted a study regarding long-term prestress losses in the structure. For understanding and sustaining the structure throughout its remaining service life, accurately quantifying prestress losses is important. Two approaches are used to predict long-term prestress losses on the Varina-Enon Bridge. The first approach involves a finite element computer model of the bridge which run a timedependent staged-construction analysis to obtain predicted prestress losses using the CEB-FIP '90 code expressions for creep and shrinkage. The second approach involves the compilation of data from instrumentation mounted in the bridge to back calculate the effective prestress force. The analysis using the computer model predicted the prestress losses as 44.6 ksi in Span 5, 47.9 ksi in Span 6, 45.3 ksi in Span 9, and 45.9 ksi in Span 11. The prestress losses estimated from field data were 50.0 ksi in Span 5, 48.0 ksi in Span 6, 46.7 ksi in Span 9, and 49.1 ksi in Span 11. It can be seen that relative to the results of field data estimations, the finite element analyses underestimated prestress loss, but given the degree of uncertainty in each form of estimation, the results are considered to fit well.
Master of Science
In order to apply a precompression force to concrete structures, post-tensioned concrete employs stressed steel strands. To construct lighter, stiffer structures, this popular building technology can be used. The steel strands undergo a reduction in force known as prestress losses over time. To make good decisions about the remaining life of a structure, the precise calculation of the prestress losses is very important. The Varina-Enon Bridge is a post-tensioned concrete box-girder bridge in Richmond Virginia. In July of 2012, observation of flexural cracks in the bridge by the inspectors promoted a study regarding long-term prestress losses in the structure. Two techniques are used to predict long-term prestress losses for this bridge. A computer model of the bridge is used in the first method to calculate losses using the design code. In order to measure prestress losses, the second technique used data from sensors mounted on the bridge. It was found that the estimation of losses closely matched those predicted at the time of the bridge construction and the computer model results. Based on this the final conclusion is made that the prestress loss in the Varina-Enon Bridge is not significantly more than expected.
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49

Thorsell, Thomas. "Advances in Thermal Insulation : Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings." Doctoral thesis, KTH, Byggnadsteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-90745.

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We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment.  Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60% if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hygrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The procedure incorporates specific steps exposing the wall to different climate conditions, ranging from cold and dry to hot and humid, with and without a pressure gradient. This study showed that air infiltration alone might decrease the thermal resistance of a residential wall by 15%, more for industrial walls. Results from the research underpin a discussion concerning the importance of a holistic approach to building design if we are to meet the challenge of energy savings and sustainability. Thermal insulation efficiency is a main concept used throughout, and since it measures utilization it is a partial measure of sustainability. It is therefore proposed as a necessary design parameter in addition to a performance indicator when designing building envelopes. The thermal insulation efficiency ranges from below 50% for a wood stud wall poorly designed with incorporated VIP, while an optimized design with VIP placed in an uninterrupted external layer shows an efficiency of 99%, almost perfect. Thermal insulation efficiency reflects the measured wall performance full scale test, thus indicating efficiency under varied environmental loads: heat, moisture and pressure. The building design must be as a system, integrating all the subsystems together to function in concert. New design methodologies must be created along with new, more reliable and comprehensive measuring, testing and integrating procedures. New super insulators are capable of reducing energy usage below zero energy in buildings. It would be a shame to waste them by not taking care of the rest of the system. This thesis details the steps that went into this study and shows how this can be done.
QC 20120228
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50

Emre, Sunal Egill. "Attefallshus insulated with Vacuum Insulated Panels." Thesis, KTH, Byggnadsteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-196019.

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Stockholm lies at the top in Europe in terms of population growth. It is growing from 30,000 to 40,000 residents each year and therefor puts high demands on the regions development. One of the governments reactions to this housing problem was to approve a bill that would simplify the regulatory framework in the planning and building act. It will among other permit owners of a one-or two family houses to build a 25  compliment housing without a building permit, so called attefallshus. In this final project, a small 25  house is designed. The house was designed to have thin exterior walls to maximize the indoor living space and also to fulfill all the Boverkets regulations for permanent housing. Vacuum Insulated panels were used as an insulation material in the envelope to achieve the extra thin exterior walls to maximize the living space. Various different simulations were done to simulate: Heat- and moisture transfer through the exterior walls, thermal bridges, energy calculations and the daylight factor inside the house. Additional calculations were done in Excel to compare the mean U-value calculated in simulations. The moisture transfer simulation did show that there should not be any moisture problems in the exterior walls. The mean U-value calculations in Excel and in the simulations showed values less than the limitations of Boverkets building regulations.
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