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This thesis describes a portion of the ongoing development of a novel self-healing cementitious material system named LatConX originally proposed by a group of researchers at Cardiff University. The research reported was undertaken with the aim of furthering understanding of the system’s long-term behaviour, ultimately with a view to providing predictions for the performance of the system over a structure’s working life. This aim is accomplished through a combination of experimental and numerical research. An experimental series is presented which investigates the stress relaxation behaviour of polyethylene terephthalate in order to establish how the stress induced by heat-activated restrained shrinkage varies with time. Results of these experiments displayed very little stress reduction from the peak stress, with less than a 5 % loss observed over a 124 day period. The development of a new one dimensional transient thermomechanical model for viscoelastic behaviour of pre-drawn polyethylene terephthalate is then described. This model is shown to be able to reproduce the observed experimental behaviour with good accuracy. The polymer model is coupled with a number of other constitutive models for the behaviour of steel and concrete, thus forming a model for the material system as a whole. This coupling is undertaken within the framework of an idealised simply supported beam with a strong discontinuity for the simulation of a central crack hinge. The model is validated against experimental data and design code predictions. Design considerations for the LatConX system are discussed and modified design equations derived. Parametric studies are presented investigating the structural performance and material costs of beams incorporating the LatConX system compared with that of standard reinforced concrete beams. Encouraging results are reported suggesting that the LatConX system has the potential to simultaneously improve long-term durability and structural performance of reinforced concrete structures and reduce the initial material costs by replacing a percentage of the reinforcing steel with shape memory polymer.

Understanding uncertainty is an important part of any scientific measurement process and the ability to evaluate and understand uncertainty is a requirement of the International Standards for quality control. The basic uncertainties relating to the measurement of airborne sound insulation in the field can be assessed using the methods in BS5725. However, identifying the components that contribute to the total variability is beyond the scope of the standard and more detailed information requires a more advanced approach. Recent developments in the “Guide to the expression of uncertainty in measurement” (GUM) suggest an approach can be used where identification of the input variables and their likely contribution will result in a solution that can be modelled providing enough information is available. However, recent research on uncertainty in sound insulation using GUM has identified problems involving the correlation between frequency bands, which leads to an overestimate of uncertainty. An empirical approach is used in this thesis, which incorporates advanced analysis of variance (ANOVA) and a specific model called Gauge Repeatability and Reproducibility (GRR). It enables the components of variance in the measurement system to be partitioned and provides an estimate of their contribution. In addition, ANOVA highlights any interaction between factors. In the GRR, carried out on a lightweight timber floor and a heavyweight concrete floor, significant interaction was detected between the operator and part. Good agreement is obtained in the repeatability and reproducibility calculated for each construction and the samples are combined with measurements of test elements that provide a wider range of sound insulation performance. The uncertainty associated with the instrumentation, operator, interaction and part are calculated in each case. It is shown that the interaction component is important and should be contained in any approach evaluating uncertainty. Further evidence reveals that the total uncertainty in the measurement process is dependent on the construction being measured.

Håldäck är en vanligt förekommande betongprodukt som ger lägre materialkostnadader och används bland annat där man önskar längre spännvidder för en öppnare planlösning. Strängbetong konstruerar, tillverkar och monterar prefabricerade betongelement där håldäck är en av de produkterna. För att få en stabil och robust konstruktion behöver betongelementen kopplas samman. Detta för att undvika fortskridande ras av en byggnad ifall en olycka skulle inträffa som t.ex. påkörning eller explosion. Examensarbetet syftar till att undersöka två så kallade raskopplingar mellan ett håldäck och en betongvägg. Ena kopplingen är enligt Strängbetongs standard och utformas med en bygel igjuten i håldäckets kanal, denna standardlösning ger dock extra arbete vid tillverkningen. Därför undersöks ifall det är praktiskt möjligt att montera bygeln i fogen mellan två håldäck istället. Försöken är till för att undersöka ifall armeringsbygeln blir tillräckligt omsluten av betong och att fogen därmed inte spricker sönder vid belastning av järnet. Resultaten från den praktiska delen samt från den teoretiska beräkningen sammanställs sedan för att kunna se om praktiken skiljer sig från teorin. Domkraftens dragkapacitet var 20 ton som gjorde att försöken begränsades till att enbart kunna konstatera att utdragningskapaciteten i en håldäcksfog och kanal är minst 195 kN. Resultatet från dragförsöken av armeringsbyglarna igjutna i håldäckets fog och kanal blev materialbrott i armeringen. Resultaten visar att det är möjligt att ersätta dagens standard koppling i kanalen med att istället montera bygeln i fogen mellan två håldäck. Examensarbetet kan ses som ett försök till att testa ifall kopplingen var möjlig och kan vara till grund för vidare studering. / Hollow core slabs are a common concrete product that reduces material costs and is used, among other things, where you want longer ranges for a more open plan solution. Strängbetong designs, manufactures and assembles prefabricated concrete elements where hollow core slabs are one of the products. To get a stable and robust construction, the concrete elements need to be connected. This in order to avoid progressive collapse of a building in case of an accident, such as an collision or explosion. This dissertation aiming to investigate two so-called collapse-couplings between a hollow core slab and a concrete wall. One of the connections is according to Strängbetong's standard and is designed with a S-reinforcing bar in the hollow core slab void, but this standard solution provides extra work in the manufacture. That's why it's an advantage, if it is practically possible, to assemble the bar in the joint between two slabs instead. The tests are in order to investigate whether the bended reinforcement bar becomes enought enclosed by concrete and that the concrete in the joint does not crack apart. The results from the practical part and from the theoretical calculation are then compiled to see if the reality differs from the theory. The capacity of the jack was 20 ton, which made the tests limited to only note that the pull-out capacity of a hollow core slab joint and void is at least 195 kN. The result of the tests gave material ultimate in the reinforcement. The results show that it is possible to replace today's standard connection in the void by instead assembly the bar in the joint between two slabs. The dissertation can be seen as an attempt to test if the connection is a possible solotion and the work may be the basis for further study.

As per the UKCIP 09 climate change projections the United Kingdom is very likely to experience increased sea level rise, increased winter rainfall, heat waves and an increase in frequency and severity of extreme weather events. Such inevitable impacts of climate change will require adaptation measures to be implemented for the management of existing commercial built assets if they are to continue to fulfil their primary function and support every organisation’s business operations. However, it is not clear as to how far adaptation solutions are effectively integrated into facilities or built-asset management planning? While seeking the answers to above questions, this thesis develops an approach for facilities and built-asset management, which will improve the resilience of existing commercial built assets to future physical climate-change impacts. The study undertakes a participatory study with a large commercial organisation and a questionnaire survey of UK facilities managers. The participatory study involved selective team of facilities management and operational (FM&O) professionals from a commercial organisation that managed around 3,400 built assets valued at £370 billion in 2003–05 in the United Kingdom. By working closely with the organisation, an approach to built-asset management was developed which integrated the existing UKCIP decision-making framework and UKCIP02 climate-change projections. In developing this approach, the strategic risk perception and managerial attitude to climate change were identified and included as important factors affecting the decision-making process. To test the wider applicability of the decision-making framework that was developed in the participatory study, a questionnaire survey of the wider facilities management community was undertaken. It was deduced from the survey results that the intent and process of decision making remains constant amongst FM professionals in commercial settings – for example: (a) The experience of a financial loss due to an existing climate-related extreme event is the initiation point for strategic stakeholders for considering future action regarding climate change; and (b) The operational adaptation measures are restricted to securing insurance deals and making renewed disaster-recovery and business-continuity plans. Additional outcomes from participatory and survey study covered logistic models describing the adaptation and mitigation approaches within a commercial setting. Taken as a whole, the findings from this study show that mitigation efforts which are supported by legislation and have well defined targets achieve a strategic importance within an organisation, while an absence of such targets and external drivers means that adaptation is viewed as an operational activity and, , as a short-term activity that has to compete for funds within annual budgets. To raise the profile of adaptation within commercial organisations requires a shift in the perception of climate change as risks amongst FM&O professionals and ability to better recognize climate change impacts on the business and built asset functions. This requires action to be initiated at both governmental and organisational level. However, such action needs to consider other constraints, such as the time span of the climate change projections. In particular, as FM&O professionals consider adaptation as an operational issue for which the planning period is normally short term (3–5 years), while the long-term projections associated with climate change are for 20–30 years as a minimum. In order to support decision making, this ‘temporal scale’ discrepancy needs to be addressed. The study has demonstrated that although decision-making frameworks and projections are useful tools to the adaptation of existing commercial built assets, they need to be synchronised with the short-term business planning and operational time line. The mitigation approach due to legislative and market-performance forces is quantified and gains a strategic importance, securing substantial financial support. In contrast to this, the adaptation agenda is taken into account only in the presence of an extreme event-related financial and functional loss. In this case, adaptation to climate change remains a reactive rather than a planned process and lacks legislative drivers. In the absence of legislative impetus and a standardised quantitative assessment method, it is difficult to derive short term or long-term targets according to which maintenance management interventions can be planned and strategic support can be achieved. In addition, the perception of built-asset managers about climate change risk is also found to be affecting the adaptation and mitigation agenda for built-asset maintenance and management.

Earth has been used as a reliable building material for many thousands of years. Recently there has been a world wide renaissance in the use of earth as a building material due to its architectural versatility and environmental sustainability. However, in the United Kingdom it is regarded by the majority of building professionals as either obsolete or a novel historical material. The utilisation of earth as a modern building material and the repair of historic earth building structures is retarded by the uncertainty of the knowledge of the properties of the material. This thesis considers earth building materials as composite materials containing a cohesive, low compression modulus binder fraction, a high compression modulus aggregate fraction, and a fibre fraction. The compression properties of a building material without fibre content (cob matrix material) are described in terms of the interaction between the binder and aggregate fractions, and moisture and the binder fraction. The effect of the moisture content of the material upon the compression failure mechanisms is described. Values of compression modulus predicted by a rule of mixtures equation are compared to experimental results for this material. The following mechanisms are proposed to account for the apparent discrepancy between the predicted and experimental results: • the effect of pore size distribution and the proportions of binder and aggregate fractions upon strain magnification within the material • the effect of an efficiency factor, primarily dependent upon the proportion of binder and aggregate fractions, which determines the degree to which the potential modulus of the material is realised. Time Domain Reflectometry is employed for repeated, real time, non-destructive measurement of the moisture content of an external cob wall. The results of these measurements are analysed and discussed. This thesis proposes that consideration of cob as a composite material has developed a paradigm which will enhance the level of understanding of all earth building materials, enabling the manipulation and accurate prediction of their structural properties. This will be an important contribution to the realisation of the significant sustainable qualities of earth building materials by the current construction industry. -

No description available.

No description available.

A lot of people experience sound pollution in their home even though the demands for sound levels are met. The majority of new constructions does not only fulfill the basic requirements but also reach the higher classifications that are presented by the Swedish Standards Institute. Even though this is the case, people still make complaints about being disturbed by noise. Bjerking AB states that they require an inquiry if it is possible to mask the noise from a disturbing sound with a background sound. The study also investigates if it is possible to mask the noise even more with a filtered background sound. The thought behind the masking of the sound is to add a background sound that is able to cover the disturbing sound and therefore make it harder to perceive. A test environment has been created based on the question about the possibility of masking a flushing sound from a toilet with a background sound. Twelve test persons have participated in the test using a signal when they identified the disturbing sound during different test scenarios. The result showed that it was in most scenarios possible to mask the disturbing sound with background sound and even better with a filtered background sound. Continuous research is needed to create a more secure method that studies the possibility of masking flushing noise from a toilet. Other types of noise should also be studied to gain a broader picture if masking can be applied to mask noise in residencies.

All around the country there are historic buildings considered to have a cultural heritage value and are therefore historically important and should be preserved.  They are an important part of a city’s identity and it is important to preserve them so that they can keep being part of our societies. The thesis of this study is therefore to explore the possibilities for how these buildings can become more energy efficient, so that they can meet today’s standards and keep being functional. Cultural heritage buildings can be subject to legal preservation and for every building there are individual preservation requirements that are to be considered. Three fictional buildings with different preservation requirements have thus been created to take into consideration all the challenges and possibilities that can present themselves.   The result shows the multitude of opportunities, but that these can vary greatly between buildings and cases. It is always the individual building’s preservation requirements and its premise that are the determining factors for if the solutions are applicable or if the value is affected negatively. Thus, a thorough prestudy is always significant before every project. Window retrofit solutions are mostly made of adding additional glass and sealing, which in many cases can be applied to existing windows without further complications. Ventilation and heating systems, however, require more space and are in most cases a more difficult retrofit action. Though, in some cases existing canals and pipelines can be utilized for installation of the new system, without affecting the heritage value negatively. Energy efficient retrofits in cultural heritage buildings could bring value and should therefore be considered. By retrofitting the building’s existing systems with newer and modernized techniques the indoor climate can be greatly improved, and thus the building’s use can be broadened, and it can continue to be a functional part of the city.