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.

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.

Despite the widely recognised importance of the impact that built environment has on health and well-being, the concept of sustainable housing is still regarded largely in terms of environmental sustainability. However, given the urgent need to increase the quantity and sustainability of new homes in the UK, it is essential that the design and delivery of sustainable housing does not neglect health and well-being aspects that are essential for enhancing the quality of life and the development of sustainable communities. This study focuses on the ‘soft’ features of sustainable housing, that is, the non-technological components of housing and neighbourhood design that can affect occupants’ health and well-being as well as their satisfaction with their homes. The research aims to conceptualise and identify these ‘soft’ features of housing design and establish whether the opinions of housing users regarding their importance are aligned with those of the housing providers. Using a case study approach, the study also assesses the extent to which such features are being provided by new housing developments. The research begins with a review of literature of the sustainable housing and healthy housing concepts, which lead to the development of a framework for sustainable housing design with an emphasis on health and well-being. Building on this foundation, three phases of the methodology were developed to address the aims of the research: Firstly, a content analysis of sustainable housing standards is carried out, followed by a survey to ascertain the relative importance that housing stakeholders attach to these ‘soft’ features, and lastly, six housing developments are evaluated with regards to their provision of these features. The findings reveal that housing user preferences are not always aligned with those of housing providers, and indeed, a number of notable differences in opinion are also found between the private sector and social housing providers. Lastly, assessment of the six case studies indicates a low level of provision of such features new housing developments. These findings indicate that a more comprehensive approach is necessary for addressing and providing for the softer features of housing and neighbourhood design.

From the literature survey it is clear that reinforced brickwork pocket type retaining walls are a well established form of construction in the USA, however, only a small number have been built in the UK. This is surprising since coat studies have consistently indicated that pocket type construction la more economical than fair-faced concrete walls. The available and forthcoming design guidance on reinforced brickwork is reviewed. The main aim of this research was to Investigate the structural performance of pocket type walls in relation to the requirement of the Draft Code for Reinforced Masonry. Reported within are the method and results of an experimental research programme. In all six walls and fifteen beams were tested. The parameters examined were brick type, percentage of reinforcement, slenderness and shear span ratio. Flexural failure occurred in all the walls and in the medlum-1ightly reinforced beams whilst only the heavily reinforced beams failed in shear. The experimental results were predicted accurately when analysed using the flexural design equations in the Draft Code. However the Code requirements for shear appear to be unduly conservative. Concurrent with the experimental work a finite element program was developed to analyse pocket type walls. In spite of the many assumptions made in the modelling of material properties there was good agreement between analytical and experimental results. Subsequently a parametric survey was undertaken. The variables selected for examination were slenderness, pocket spacing, panel thickness percentage of reinforcement and arching action in the panels. Both rectangular and flanged sections were investigated. The results indicated that the Draft Code gave good predictions when flexural failure of the stem occurred. But when panel failure developed neither yield line analysis nor arching theory was able to predict collapse. Guidance is given on the sizing of panels. It is concluded that pocket type walls, when designed to the requirements of the Draft Code, perform adequately at serviceability and ultimate design loads for pocket spacings up to 1.0m. Further experimental work is necessary to establish whether the guidance given in the Code is applicable to walls with pocket spacings greater than 1.0m.

This research focuses on developing a Construction Supply Chain Risk Management (CSCRM) framework that can be adapted by developing countries to help construction projects make better use of materials procurement in their organisations, and to improve construction project management by effectively controlling the project to avoid project cost overruns. The research is conducted in Myanmar and all the companies studied, including the case-studies, are operating in Myanmar. The proposed CSCRM framework includes the plan, resources, process and control model part. The model suggests the development of close relationships with various stakeholders of the project for better use of the Risk Management Model. Without a proper CSCRM framework, a construction company in Myanmar can encounter a cost overrun of about three times the estimated total cost. However, the use of the proposed CSCRM framework can minimize the cost overrun by amounts of two times the total project cost. The results of case studies in three construction companies in Myanmar confirm that the proposed model is effective in managing the supply chain of construction projects in Myanmar, with effective mitigation of cost overrun risks and maximization of competitive advantages of the company.

This thesis provides an investigation into the structural behaviour of cold-formed steel zed- and channel-section purlins when subjected to uplift loading in purlin-sheeting systems. In pre-buckling, an analytical model is presented to describe the bending and twisting behaviour of partially restrained zed- and channel-section purlins when subjected to uplift loading. Formulae used to calculate the bending stresses of the roof purlins are derived by using the classical bending theory of thin-walled beams. Detailed comparisons are made between the present model and the simplified model proposed in Eurocode EN1993-1-3. In buckling, a numerical investigation is presented on the buckling behaviour of partially restrained cold formed steel zed- and channel-section purlins when subject to transverse distributed uplift loading. The buckling behaviour of zed- and channel-section purlins of different dimensions subjected to uplift loading under the influence of rotational spring stiffness applied on the middle line of the upper flange is examined. In the post-buckling, nonlinear finite element analysis models are created for the partially restrained cold-formed steel zed- and channel-section purlins subjected to transverse uniformly distributed uplift loading. The analyses are performed by considering both geometric and material nonlinearities, and corresponding design curves of zed- and channel-section purlins are established.

The aim of this research is to develop a coupled thermo-mechanical damage model for implementation in finite element software in support of fire-induced collapse assessment of steel structures. The need for properly modelling steel deterioration behaviour remains a challenging task in structural fire engineering because of the complexity inherent in the damage states of steel at large strains and high temperatures. A fully three-dimensional damage-coupled constitutive model is developed based on the hypothesis of effective space elastoplasticity and isotropic damage theory. The coupled damage is simulated by a coupling formulation between a mechanical damage component and a thermal damage component in attempt to capture the coupled damage growth under combined actions of mechanical loading and fire loading. The proposed damage model comprises a limited number of parameters that could be identified at unloading slopes of stress-strain relationships through tensile coupon tests. Alternatively, an inverse analysis type of calibration procedure could be adopted when coupon test data is unavailable. The proposed damage model is successfully implemented in the finite element software ABAQUS and calibrated with a comprehensive range of experimental results and established numerical results. The damage-affected structural response is accurately reproduced under various loading conditions and a wide temperature range, demonstrating that the proposed damage model is a useful tool in giving a realistic representation of steel deterioration behaviour under combined actions of fire and mechanical loads. Three-dimensional FE models of a five-storey and a ten-storey steel-framed office building are developed in ABAQUS and the proposed damage model is adopted in assessing their susceptibility to progressive collapse. Three types of accidental scenarios are investigated : (i) fire only scenario, (ii) post-blast fire scenario, and (iii) fire-triggered explosion scenario. The location of the compartment where triggering loads occur is varied and the most vulnerable location is at the mid-height of both building systems. Estimation of ultimate failure time by incorporating damage model with the suggested damage parameter set has the potential to be utilized as a useful tool in helping designers to determine how much time is realistically available for evacuation before progressive collapse occurs in this type of buildings. Results show that the proposed damage model significantly affects the limit state of steel buildings under fire, and especially under combined actions of blast and fire. Compared to conventional numerical approaches, the consideration of coupled thermo-mechanical damage accumulation results in an 8.25% ∼ 23.47% decrease of collapse resisting time. A key finding from this study is that the alternative load path, which is a crucial factor in deciding the survival of buildings upon local column failure, may be severely compromised due to the coupled thermo-mechanical damage propagation in surrounding columns. Based on the identified collapse mechanisms, effective strategies are suggested to improve the survivability of buildings under blast and fire.

Supplemental passive dampers are generally considered as an effective tool to control the seismic response of multi-storey buildings. Since the optimum placement of passive dampers in buildings can potentially improve the structural performance or reduce construction cost, there is an increasing number of researchers engaged to optimize the damper placement in buildings. Given that a large number of studies have been conducted to investigate damper placement methods, a systematic method or a clear conclusion for strategically distributing dampers in buildings is not presented in any building guidelines. The main limitations of current damper placement studies may include the lack of focus on collapse resistance of retrofitted buildings, on beam and column nonlinear behaviors, and the lack of considering the variations of earthquake characteristics and intensity levels. The fundamental damper placement issue can be separated as the distribution of dampers throughout the height of the buildings and the distribution of dampers in different bays in building frames. In this research, both distributions are explored and their effect on the collapse performances of buildings under strong earthquakes is thoroughly studied. The effectiveness of advanced damper placement approaches is evaluated by comparisons with classical damper placement methods. Considering the uncertainty in earthquake ground motion characteristics, multiple ground motions scaled to various intensity levels are involved to evaluate the seismic performance of buildings. Finally, major conclusions towards the philosophy of the strategic damper placement in practical building constructions are presented in terms of the overall structural performance under strong ground motions.

Reinforcement corrosion is one of the major causes of deterioration of reinforced concrete structures exposed to aggressive environments. Deterioration caused by reinforcement corrosion reduces the serviceability and load bearing capacity of the concrete structures to an extent of serious structural failure. Consequently, this increases the resources required for the maintenance and rehabilitation over time. Due to uncertainties associated with the performance deterioration, it is difficult to accurately assess the residual strength and remaining useful life of corrosion damaged concrete structure. Therefore, the reliability-based performance assessment techniques based on stochastic deterioration modelling has significant potential for assessing the present and future performance of these structures. This can be ultimately helpful in sustainable and cost-effective infrastructure management. This research presents new analytical methods for evaluating concrete crack evolution, estimating rebar bond strength degradation and predicting residual flexural strength of concrete structures affected by reinforcement corrosion. At first, cracking in cover concrete due to reinforcement corrosion is investigated by using rebar-concrete model and realistic concrete properties. The bond strength evolution of the corroded rebar is then evaluated at different stages of cover cracking by considering adhesion, confinement and corrosion pressure acting at the bond interface. Furthermore, the residual flexural strength of concrete beams is predicted with consideration of bond failure between the rebar and concrete. The gamma process is adopted for stochastic modelling of concrete crack growth and strength deterioration with uncertainties. Then, a time-dependent reliability analysis is undertaken to evaluate the probability of failure in serviceability and load carrying capacity of corrosion damaged concrete beams. Optimal repair planning during the service life is also determined by balancing the cost for maintenance and the risk of structural failure. Finally, the results evaluated from the proposed methods are examined by available experimental and field data and the applicability is demonstrated by numerical examples. The results obtained show that the proposed methods are capable of evaluating the performance and can also provide risk-cost balanced repair strategy during the lifetime of corrosion damaged concrete structures. The knowledge gained from this research contributes to the better understanding of the mechanics of performance deterioration associated with reinforcement corrosion. Furthermore, the methods presented in this study could be helpful in assessing the actual state of performance deterioration and making decision regarding the optimal repair.