Resilient bars provide cheap, effective sound insulation. They are increasingly popular in timber floor/ceiling assemblies in the UK following the upgrading of Building Regulations requirements. However, the behaviour mechanisms providing resilient bars with their insulating properties are not well understood. The effects of specific detailed features on their performance are assumed or estimated empirically. Myths relating to property-performance correlation prevail among various product manufacturers. Previous experimental studies revealed either overall effect or only covered the stiffness in the vertical direction. Spring and rod models used elsewhere also failed to predict three-dimensional, asymmetrical facets of resilient bar behaviour. This research investigated the influence of various three-dimensional resilient bar features through examining hypotheses: resilient bars act as springs (either vertical, bending, cantilever or spring hinge), or stiffeners. As these hypotheses are associated with certain material and geometrical features, the results revealed each's influence and relative importance. Three types of test were designed: vibration transmission, apparent stiffness and modal tests. Two representative but distinctly different resilient bar products were chosen as test subjects, which covered the features of interest and involved controversies. Vibration transmission tests were conducted on a series of configurations based on small-scale structures, which could not only demonstrate overall performance but allow detailed parametric investigations. Apparent stiffness tests on small samples enable isolation of spring effects so that their individual contribution could be evaluated. Modal tests revealed how resilient bars modified the vibration modes of the attached plate. By synthesizing the data from the above three angles together with data in the literature, the influence of key features was inferred and evaluated. Mass-spring-mass modelling and statistical energy analysis were carried oout which enhanced understanding of the system's behaviour. The findings led to an optimised resilient bar design and a patentable acoustic hanger system. The latter was prototyped and tested on a floor/ceiling assembly. The results showed that it was more advantageous than current resilient bar systems.

The innovation of natural daylighting light pipe took place more than twenty years ago. Since then its daylighting performance has been reported in a number of studies. To date, however, no mathematical method that includes the effect of straight-run and bends within light pipes has been made available. Therefore, a generalm athematicalm odel for light pipes is desirablet o assessa nd predict its daylighting performance.F urthermore,s uch a generalm odel can enablet he assessmenot f light pipe system's efficiency and potential in energy saving. A modified form of daylight factor, Daylight Penetration Factor (DPF), has been introduced to build a sophisticated model that takes account of the effect of both internal and external environmental factors, and light pipe configuration. Measurementsa nd mathematicalm odelling activities aimed at predicting the daylighting performance of light pipes with various configurations under all weather conditions in the UK were undertaken. A general daylighting performance model, namely DPF model, for light pipes was developed and validated. The model enables estimation of daylight provision of the light pipes with a high degree of accuracy, i. e. R2 values of 0.95 and 0.97 for regression between predicted and measured illuminance were respectively obtained for the above model. The DPF model uses the most routinely measured radiation data, i. e. the global illuminance as input. Considering that in real applications, light pipes installed in a particular building may not receive the full amount of global illuminance as measured by local meteorological office. This may be due to partial shading of the light pipe top collector dome. Therefore, to enable the application of the DPF model in practical exercisesf undamentalw ork on sky diffuse illuminance measurementsh ave been undertaken. An exhaustive validation has been carried out to examine the DPF model in terms of the structure of the model and its performance. The DPF model was compared against studies by other independent researchersin the field. Independentd ata setsg atheredf rom a separates ite were used to validate the performance of the DPF model. Comprehensive statistical methods have been applied during the course of validation. Relevant, brief economic and environmental impact of the technology under discussion has also been undertaken. One of the main achievementso f this work is the mathematicalm ethod developedt o evaluatet he daylighting performance of light pipes. T'he other main achievement of this work is the development and validation of the DPF models for predicting light pipes' daylighting performance.

The term "lime" comes from the word limestone. Limestone rocks were converted to lime powder by burning (calcining). The process of converting limestone to lime was an old process and it has been well documented, archaeologically. It has been established that the production of lime is the oldest industrial process can"ied out by humankind, dating back thousands of years. In fact, 3650 years ago Moses instructed the people of Israel, after they crossed the Jordan River, to set up large stones and whitewash them with lime and write the laws of God in lime. Lime was the most commonly used cementatious binder until about a century ago, when its use started to decline. It was replaced by Portland cement, a material essentially developed for structural purposes in the era of the industrial revolution. Portland cement has certain advantages over lime. The material develops strength and hardens faster for work to be carried out at a greater pace with better quality control and agreed standards. It has now become the dominant cementitious binder, part of it due to aggressive marketing of the material by the manufacturers. The use of Portland cement in the restoration and conservation of old buildings and structures in the UK over the past few years has resulted in a series of problems and cost millions of Pounds to eradicate. The decline in the use of lime in many countries has not only caused a diminution of its production, but has also contributed to a gradual disappearance of the traditional skills required both to produce a high quality product and to use it in construction. Therefore it is necessary to reintroduce and revive the old tradition of using lime by providing more information about its production and use. At present there are no comprehensive standards or code of practices, British or European to aid engineers and contractors in the use of hydraulic and non hydraulic limes in construction. BS EN 459 (2001) gives guidance on the chemical and physical properties of limes but it does not provide vital information about lime-based mortars e.g. mix proportions, mixing process, bond with masonry units, curing methods and all other necessary aspects to assess in the use of the material in construction. At present it is very easy for engineers, contractors and consultants to misuse lime mortars in new construction or in restoration and conservation of old buildings. Part of the decline in production of lime and reluctance of use in construction is due to the lack of understanding of the material properties and its performance in structures. Therefore it is necessary to examine and revive the old tradition in using lime mortars in construction and look at the new technologies used presently in the production process in order to provide the necessary background and information to aid the use of the material The present study provides a literature review, test results, discussions, conclusions and background information to set up standards in the production and use of hydraulic and non-hydraulic limes and their mortars in the construction of new buildings and the restoration and conservation of old buildings. Hydraulic and non-hydraulic limes have an excellent track record in buildings through history but their use in the UK was missed for some thirty years or more. Part of the reason for undertaking this research programme was to examine the properties of pre-packaged hydraulic limes available in the market at present. The properties of limes vary considerably dependent on the raw materials, composition and manufacturing process. The results of this study showed that there was a great variation in the properties and performance of limes and their mortars. The results also showed that the properties of lime mortar improved by adding different percentages of POliland cement. The research examined the effect of sand grading on the lime mortars compreSSIve, splitting and brick/mortar bond strength. The thesis also investigated the effects of using different casting moulds and curing methods on mortar strength. The results showed that the porosity of lime mortar was one of the reasons it was a success in the past and why it was so important nowadays to use it in the restoration and conservation of historic buildings.

Estimating and bidding a job is one of those essential processes at the heart of a contractor's business. Risk and uncertainty are major considerations in bidding decisions for construction projects. Numerous factors need to be taken into account when making bidding decisions which make them multi-criteria decisions. The present study focuses on developing multi-criteria decision making models to assist in bidding decisions. The Analytical Hierarchy Process (AHP), which is a multi-criteria decision making tool, is used to quantify risk encountered in bidding decisions. The AHP has been employed to model both the bid/no bid and mark-up decisions. The data required for this study was collected from thirty firms operating in Gaza Strip by way of a written structured questionnaire. The data was analysed using the Criterium Decision Plus Software based on the AHP. Ten factors were selected to affect bid/no bid decisions while eleven factors were chosen to influence mark-up decision. Results from the questionnaire survey supported previous studies that profit is not the most important factor in making bid/no bid and mark-up decisions. The results also indicate that the most important factors when making the bid/no bid decision are: the 'need for work' followed by the 'company strength in industry' and 'payment methods'. For the mark-up decision, the 'need for work', 'owner/client and consultant identity' and 'project size' are the most important factors. A real life case study was used to demonstrate the application of the two models. Twelve meetings were conducted with a contractor working in Gaza Strip construction industry in order to gather the required data for the validation. The case study consisted of three different projects, road works, electromechanical and building projects, and the contractor had to make a decision on which projects to bid for and then which of them will result in a higher mark-up. The validity of the two models was confirmed by applying a two-stage Linear Programming (LP) approach to the data obtained from the case study. The results from the LP approach agreed with the outcome from the AHP. The developed AHP models can be easily used by the contractors to assist in making bid/no bid and mark-up decisions. This study investigates the Fuzzy Sets Theory, which is a mathematical approach used to characterise and quantify uncertainty, as a bidding strategy. This study summarises the work that has been done to-date reviewing the fundamental concepts and applications of the Fuzzy Sets Theory in construction. Fuzzy Sets Theory was found to be used widely in construction research but most studies were found theoretical. The research also examines the challenges of using the reverse auction as an open bidding process. In construction industry, reverse auction is one such technique that uses secured Internet technology for tendering process. Advantages of on-line bidding include: the ability to submit more than one bid, time benefits, increasing competitiveness among contractors and attracting unknown bidders. The main drawback of reverse auctions is that the award of the product/service will be based on the price rather than on the quality of the product or service. Furthermore, security and legal issues need further considerations when forming e-contracts for the procurement of construction services. Selecting a suitable contractor to execute a particular project is an important decision for the client to take. Awarding construction contracts based on the price only is not always a successful strategy for contractor selection as it could result in construction delays and cost overruns. In addition to price, factors such as quality and safety need to be taken into account when making the contractor selection decision. In this study, two methods for contractor selection were compared: the points method and the Analytical Hierarchy Process. The two methods were applied to a real life case study for contractor selection. Financial and Quality factors were considered to affect the contractor selection decision. Both methods resulted in selecting the same contractor for executing the project under consderation. The Analytical Hierarchy process provides a flexible and computer based method for contractor selection decision.

No description available.

This thesis investigates the feasibility of the use of Low or Zero Carbon Energy Sources (LZCES) in the built environment and the development of an innovative Integrated Renewable Energy Planner (IREP) tool. It can be divided into four main research areas; an investigation into the on-site renewable energy resource, an analysis in the building energy usage profile, a development of a decision-making tool for the rapid identification of the most appropriate LZCES option and a post occupancy monitoring and modelling of a building. This research work details the following considerations of LZCES: passive solar space heating modelling (PSSH); performance of building integrated including solar water collector (SWH); solar photovoltaic (SPV); wind technology (WT); ground source heat pump (GSHP); tri-generation (TriG); biomass (BioH) and rainwater harvesting (RWH). Recorded Chartered Institute of Building Services Engineer (CIBSE) data from fourteen cities around the UK were used to assess the wind, solar electric, solar passive thermal, solar water thermal, ground source and rain resource. As part of this project, an unoccupied solar house was monitored for one summer and one winter month in East Whitburn, Scotland. A detailed investigation into the effect of external temperature, irradiance and thermal mass was conducted on building perFormance and indoor temperature. It was found that the estimated internal temperature simulation was between 2% to 10% different from the monitored temperature. It could be improved if the thermal mass and ventilation rate were estimated more accurately. A collection of manufacturers' data from 10 WTs, 10 SWHs, 3 SPVs, 2 GSHPs, 2 BioHs, 3 Tries and 2 RWHs was carried out in order to test the performance of the IREP tool. Energy, economy and CO2 saving simulations were done on a number of LZCES systems. A final assessment of the number of different options and their impact on the cost, energy and CO2 saving was performed in order to assess the best combination possible. Future development of the IREP tool may aim to assess more accurately the output of each technologies, develop a more user-friendly facade and integrate more technologies such as light pipes, earth duct, solar wall, concentrated solar power, energy storage, UTES, waste-to-energy plant, fuel cells and to extend potentially to recycled materials. Other weather data from rest of the world could make IREP usable for other project scales and countries.

Historic buildings and monuments are a precious finite asset and powerful reminders for future generations of the work and way of life of earlier cultures and civilisations. The stone cleaning and restoration of historic buildings is a crucial element in keeping the good look, integrity and quality of the fine art, method of construction and architecture of previous civilisations. Stone cleaning is one of the most noticeable changes a building can be subjected to, which changes its appearance, persona and environmental context. In this study, a series of physical and chemical tests were conducted to further investigate, evaluate and improve the efficiency of building cleaning. Seven different abrasives were adopted for air abrasive cleaning, including copper slag (fine, medium and coarse), recycled glass (fine, medium and coarse) and hazelnut/almond shell (natural abrasive), on a total of eight masonry stones and clay bricks, including yellow sandstone, red sandstone, limestone, marble, granite, white clay brick, yellow clay brick and red clay brick. Physical investigations included sieve tests and impact tests on the abrasives, greyscale image analysis, thickness reduction measurements, Vickers surface hardness tests, Charpy impact tests and water absorption tests. Chemical investigations included Scanning Electron Microscope (SEM) and Energy-Dispersive X-Ray Spectroscopy (EDX) analyses. Sieve tests and impact tests confirmed that the abrasives utilised were fairly reliable, and the abrasives with high bulk densities were stronger and tougher than those with low bulk density. Greyscale digital image analysis indicated a lower greyscale value corresponded to a dirtier masonry surface. In general, the greyscale continuously increased with the increasing cleaning time and tended to be stable when the surface became fully cleaned. The cleanness was also introduced for assessing the effectiveness of the building cleaning. Similar trends could be observed. Both parameters proved to be significantly useful. For most of the samples, monotonic increase trends were observed between the greyscale and thickness reduction. The image analysis on greyscale and the thickness measurement were two useful methods for assessing the cleaning degree of a masonry stone or clay brick. Based on the analysis on all the testing data, it is possible to recommend a more suitable abrasive for each masonry stone or brick. For granite and red clay brick, medium glass produced the best performance, while for limestone, marble and red sandstone, fine glass was promising. For yellow clay brick, fine slag could be the best option, while for yellow sandstone the natural abrasive was found to be the most suitable. vi The Vickers hardness test results indicated that a larger hardness corresponded to a harder masonry surface. Also the surface hardness continuously increased with the increasing cleaning time but at a decrease rate. Most of the increasing trends of the surface hardness could be approximately expressed using parabolic relationships. Granite was found to be the hardest, and followed by marble and limestone. However, there were no big differences in the surface hardness between yellow clay brick, yellow sandstone, red sandstone and white clay brick. The impact resistances of seven masonry stones and bricks were obtained by conducting the Charpy impact resistance tests. Granite showed the highest impact resistance among all the stones and bricks and was followed by marble, limestone, clay bricks and sandstones. The stones and bricks with higher impact resistances also had higher hardness values but lower water absorptions. The water absorbing capacity of the seven masonry stones and bricks was quantitatively determined. Two types of clay bricks showed the highest water absorptions, and the water absorptions for limestone, yellow sandstone and red sandstone were also quite high. However, the water absorption of marble and granite was found to be very low. Larger water absorption corresponded to a softer stone or brick, while smaller water absorption corresponded to a harder stone or brick. The chemical investigations by using the SEM and EDX techniques showed that the chemical substances on the masonry surface varied largely for different types of stones and bricks. This study showed the way to detect such soiling using chemical analysis by monitor the changes in chemical elements and compounds during the building cleaning. Finally, comprehensive conclusions were presented, together with useful suggestions for future work.

The recycling of demolished masonry rubble as the coarse aggregate in new concrete represents an interesting possibility at a time when the cost of dumping such material is on the increase. With growing concerns over the environmental impact of aggregate extraction and the continued rise in aggregate demand in the UK, it is clear that the market is now there for recycled and secondary aggregates. The present investigation consists of experimental and theoretical studies into the effects of using recycled aggregates to produce concrete instead of virgin aggregates. The aggregates used have been recycled from construction and demolition waste. The recycled aggregates were predominately made up of crushed bricks but the aggregates did contain impurities such as timber and mortar. New bricks were crushed to form an aggregate in order to investigate the properties of brick as a material without impurities. The physical properties of the various aggregates were firstly examined and compared with granite aggregate, an aggregate proven in the production of good quality concrete. Concrete was then produced with the aggregates and all the physical and mechanical properties of the concretes were examined in some detail. The results showed that recycled masonry aggregates can be used successfully to produce· concrete of an acceptable standard. New test methods were presented in this investigation to determine brick porosity and water absorption. This involved the testing of broken brick fragments under vacuum, rather than the testing of whole brick units by 5hrs boiling or 24hrs submersion in cold water. The new test methods proved to be easy to perform and provided accurate results. A new test method for estimating the strength of bricks was presented. This involved point-loading of masonry specimens to obtain strength index values. From the pointload results, equations were presented relating the strength index values of brick fragments to the compressive strength of whole brick units. This involved the development of shape factors for different masonry specimens. The point-load test is easy to perform, presents a cheaper alternative to heavy compression machines and can be used on site to determine the suitability of recycled bricks as the aggregate in new concrete.

The need for improved timber grading is key to improving Scottish forestry: the majority (80%) of the sustainable softwood population in Scotland is Sitka spruce of variable quality. Current visual assessment of strength and stiffness is inaccurate, and machine stress grading in sawmills is little better due to incorrect assumptions regarding consistency within softwood species and between trees of the same stand. The author develops and evaluates non-destructive test (NOT) methods for Scottish Sitka spruce based upon impact-e9ho testing across a range of scales from plank, to log, to standing tree. Correlations between harmonic wave propagation velocity and elastic modulus of 0.62 ::; R2 ::; 0.71 were possible in Sitka spruce under a range of conditions including: genotype progeny, variable height and radial position in stem, and variable knot content. In achieving this correlation, the research also investigated acoustic parameters such as: time of flight velocity, damping ratio, and resonant peak behaviour with regard to their influence on dynamically derived moduli of elasticity. Examination of variation in wood properties (including static elastic modulus, knot content, simulated decay, density, and grain alignment) on these acoustic parameters was conducted on semi-controlled specimens of differing homogeneities. The consequences of these results should influence the development of timber NOT tools. In addition to the development of an NOT method, the author has provided the first large-scale derivation of reference values for dynamic stiffness and other acoustic properties for 35 year old logs and beams of Sitka spruce in Scotland.

Water ingress, usually by wind-driven rain, is the main cause of premature deterioration in masonry structures. Water acts as a transport mechanism for aggressive chemicals and can also undergo freeze/thaw cycles leading to bursting of the masonry microstructure. Factors such as the absorption rates of brick, water/cement ratio of the mortar, workmanship of the mason and poor design detail have all been identified as influencing the amount of water likely to penetrate a structure. It is also recognized that the majority of water ingress occurs at the brick unit/mortar joint interface, where interstices are present that allow access to the masonry interior. The size, extent and influence that the brick/mortar interface has in governing water ingress is likely to be controlled by both the applied stress level and bed orientation of the main mortar beds relative to the direction of loading. Very little research has investigated these parameters in detail. By using a new ingress measurement technique, the effect of the applied stress level and bed orientation was quantified. The main mortar beds of concentrically loaded masonry panels were found to deteriorate in their resistance to water ingress as they were orientated from perpendicular to parallel relative to the direction of loading. Poisson's ratio effects, which generated differential expansion between brick and mortar were believed to control water ingress at mortarjoints orthogonal to the main beds. Water ingress at these mortarjoints was also found greatly influenced by both applied stress level and bed orientation. Factors such as the applied pressure head of water impinging onto the panel, the variability of the brick type used, eccentricity of applied loads and the pre-wetting of panels were also found to have some controlling influence on the water ingress characteristics of masonry. Empirical modelling of water ingress dependent upon time, stress level, bed orientation and pressure head of water, was also undertaken. This enabled the volume of water ingress to be mathematically generated, with these models exhibiting good agreement with experimental data. Suggestions for future work include assessing the effect of higher applied stress levels on water ingress, verification of the laboratory work with on-site tests and the introduction of freeze/thaw testing on loaded panels to simulate an abrasive external environment. Numerical analysis using finite element modelling was also identified.