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An Analytical Study of Earth and Lime Based Building Materials in the Blumenau Region, Southern Brazil. In the last fifteen years, there has been a growing state and national interest in the preservation of historic rural settlements of the nineteenth and twenty centuries in southern Brazil. This interest has generated a need to develop appropriate conservation methods which will safeguard the integrity and technology of vernacular buildings in Brazil. This study focuses on the Blumenau region, an area in the state of Santa Catarina which was settled by German and Italian immigrants in the late 19th century. As was typical in such settlements, the immigrants brought with them European methods of construction which were then adapted to the local environment and available local materials. Though somewhat deteriorated, Blumenau still retains a large number of vernacular building types and good documentary sources of information. Thus, it provided an ideal context in which to develop a methodological approach to the study and conservation of regional building materials in Santa Catarina. Twenty domestic buildings dating from approximately 1870 to 1930 and representing the four principal types of construction in the area were chosen for the pilot project. In addition to thorough historical and archival research on the architecture and technology of the region, the study includes an in-depth scientific analysis of earth and lime- based buildings materials utilised in the rural settlement. The analytical results are interpreted in light of the historical research and recommendations are made regarding appropriate conservation and repair techniques. The study concludes with general recommendations for improved conservation practice in the region including issues of material production, training, and management. The work includes an extensive bibliography relating to the characterisation and conservation of earth and lime- based building materials. Full details of analytical techniques utilised are given in the appendix.

Radioactive radon gas, after being released from rocks, soils and building structures, can pose a significant health threat to the building occupants. This is of particular concern in tight HVAC (Heating, Ventilating and Air-Conditioning) serviced buildings where there is re-circulating air with limited fresh air intake. A thorough survey was initiated at the Hong Kong University of Science and Technology (HKUST) in 1996 and results indicate a radon average concentration of 107 Bq/m3, which is approximately 50% of the World Health Organisation's (WHO) recommended standard (200 Bq/m3). About 10% of the measurements were in excess of this WHO limit, while 46% of the samples also showed average peak radon concentrations (264 Bq/m3) in excess of this WHO limit. To overcome these elevated indoor radon concentrations, their characteristics at HKUST was studied. Radon level was found to increase linearly as a function of the length of the HVAC shut off period, and decrease exponentially upon system resumption. Radon level predictive models were developed after a series of room chamber experiments with modification factors defined to account for the indoor sinks in an effort to enhance the accuracy and applicability of the models. Following a campus-wide energy audit, two energy efficient radon management approaches were derived from the predictive models and were subsequently integrated into the existing HKUST operations. The first was defined as an Active Radon Control Approach (ARCA), where HVAC operation schedules were modified to yield an energy saving potential of around HK$2.7 Million a year. ARCA is optimised to reduce the radon dose to the HKUST occupants following the radiation protection principle of "As Low as Reasonably Achievable (ALARA)", and with considerations of economical and operational constraints. The other was a Passive Radon Control Approach (PRCA) using Polyurethane-based (P-u) paint to cover building material surfaces to reduce the radon emission.

The worldwide housing shortage has stimulated a search for appropriate, easy, fast and cost-effective new ways of wall construction. Among many technologies found to have promise is mortarless technology using dry-stack interlocking bricks/blocks. This thesis is about such mortarless walling technology and in particular: how to improve wall-construction flexibility, the effects of brick irregularities on wall alignment accuracy and wall behaviour (stiffness, strength) when subject to lateral forces. The flexibility of mortarless technology (MT) has been enhanced by the development of new bricks (centre-half bat and tee brick): the introduction of closer bricks led to the formation of two new bonds (patterns) namely Shokse and Lijuja bonds. It is now possible to construct more than half-brick-thick walls, to attach more than half-brickwide piers (buttresses) onto walls, and, using special bricks, to construct polygonal and curved walls using interlocking bricks. Three methods (theoretical modeling, physical experiments and computer simulation) were used to analyze the effects of brick imperfections on wall alignment accuracy. Theoretical analysis confirmed that brick moulders should concentrate on achieving parallel top and bottom faces rather than achieving true square-ness. Physical column assembly compared three brick-laying strategies namely: “random”, “reversing” and “replace”. The columns assembled using the “reversing” and “replace” strategies realized alignment improvement factors of 1.6 and 2.9 respectively over “random” strategy. The research also revealed that grooving, to prevent bricks making contact near their centre lines, improved column alignment by factor 2.13 and stiffness by factor 2.0, thus allowing construction of longer and higher walls without strengthening measures. In order to attain alignment accuracy in accordance with BS 5628-3:2005 in a dry-stack mortarless wall, this research recommends using full bricks with top and bottom surface irregularities not exceeding ±0.5mm for un-grooved bricks, and up-to ±0.9mm for grooved bricks. Further analysis was undertaken with respect to resource-use implications (cement, water, soil) of employing MT. Using MT will save 50% of wall construction cost and 50% cement consumption, which ultimately will reduce 40% of carbon emissions.

The research has shown that cooling in UK Office buildings can be undertaken far more efficiently than generally occurs at present, by combining the selection highly efficient air conditioning systems, such as chilled ceilings, and by ensuring building design and operation is undertaken in an energy efficient manner. The potential energy consumption, carbon emissions and running cost savings appear to be comfortably over 50% compared to current practice.

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The study investigated the relationship between design and flexibility. Proposals by designers on how to incorporate the ability of buildings to accommodate changes in the requirements of the activities to be housed in buildings over time has led to a diversity of ideas regarding the relationship between suggested design variables and the achieved flexibility. Though a number of studies have been made on specific organisations and buildings, there has been no overall investigation of the general relationship between design and flexibility. To investigate this relationship it was necessary to: 1. Propose a system of measurement by which the extent of incorporation of the design variables in design proposals could be assessed (Chapters II and III). 2. Propose a system of measurement by which the extent of flexibility of buildings in use could be assessed (Chapter IV). 3. Assess the extent of flexibility achieved by the incorporation of design variables in design proposals by a study of actual buildings in use (Chapters V, VI, VII, and VIII). The study has largely achieved these objectives. It provided methods to enable objective comparison to be made between alternative design proposals in terms of the incorporation of design variables. It provided methods to enable objective comparison to be made between buildings in terms of their flexibility in use. It became apparent that the flexibility of buildings in use was related to only certain aspects of design variables or even to only certain parts of buildings. The study demonstrated that the flexibility of buildings in use is largely predictable from knowledge about their design. It showed that current ideas on flexible designs contain many factors that are redundant to flexibility. It recommends that future proposals of designing for flexibility need to be more refined than those at the present and that will enhance the effectiveness of manipulating the potential flexibility of buildings at the design stage. The main area of further research to emerge was concerned with the operationalisation of other design variables and their testing in various building types utilising the methods defined in this study.

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