Cold weather masonry construction is a major concern for contractors as they either have to implement heating practices for laying and curing masonry systems or postpone the construction to warmer periods. This can lead to loss of productivity rate and delays in construction schedules with associated extra costs. This thesis explores a novel approach for mitigating the adverse effects of cold weather on masonry construction in early fall periods through the application of nano-alumina (NA) and nano-silica (NS) in mortar joints. The assessment criteria were based on the fresh properties, hardened properties and microstructural features of mortar mixtures and mechanical behaviour of concrete masonry prisms at early and later ages. Various test results show that NS can be successfully used to minimize the adverse effects of cold temperature on mortar joints by speeding up the hydration of cement, shortening the setting time, and increasing the strength up to 72 h.

This study investigates the effects of the arctic and subarctic climatic conditions on the built environment, urban housing in particular. The method of research and development of this thesis has been through a literature search coupled with my own working/ design experience in the North (Fairbanks, Alaska) for three years. The thesis is in three parts (chapters 2, 3» and k)» The first part makes a comparison of the climatic conditions in the different northern climatic zones within the state of Alaska, as well as comparing these to more southern climatic zones. The second part (main body of the thesis) investigates the building design responses (solutions) to the varied climatic conditions: solar radiation, temperature, precipitation, wind, and special climatic conditions (humidity/moisture potential, blowing snow, permafrost, and frost heave). This analysis is organized into "planning levels". Four planning levels are established which deal with ^) site layout/circulation patterns, (2) building size, shape, and orientation, activity/space arrangement, and (J) detailing of the building fabric. Using the parameters established in part 2, planning level 1, part 3 illustrates a townsite layout for a specific site, the Willow Site in subarctic Alaska where the new Alaska State Capital i6 to be located. The majority of people who live in the northern urban areas look to the south for their housing styles and designs as well as assess housing quality by "southern standards". Presently there are few ways for people living ln the North to evaluate the quality of housing for that particular climate except through trial and quite often error. This thesis produces an ordered listing of building/housing responses to the northern climates which can be disseminated to the public who can then better assess housing performance and quality for their particular physical environment. The information contained within this thesis would also be of use to professionals in arriving at design decisions for housing/building in northern areas. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

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Call number: LD2668 .T4 1966 F837 / Master of Science

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Wet snow accumulating and shedding from overhead transmission lines can lead to a number of serviceability, safety and mechanical reliability issues. An innovative and inexpensive method to reproduce wet snow accretions on a cable in a controlled environment is explained. Wet snow sleeves were experimentally reproduced by using this technique to study their shedding mechanism. A numerical modeling technique using nonlinear finite element analysis is proposed to evaluate the dynamic response of an overhead cable subjected to any snow-shedding scenario. A time function is associated to the mass and weight of each snow element, which enables its virtual removal from the model at the time prescribed by the user. The response of a single span of overhead ground wire subjected to total and partial snow shedding scenarios is evaluated.

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Cold acclimation entails changes in membrane composition, osmotic adjustment, alterations in the cell wall-plasma membrane interface, sugar deposition, and changes in cell wall proteins. There is evidence that a rigid cell wall may be necessary for cold acclimation. Difficulties arise in studying plant material acclimated by exposure to low temperatures, because extraneous changes in the plant material occur that are unrelated to the development of cold tolerance. In order to determine whether cell wall changes are necessary for acclimation, peas were acclimated at warm temperature (26°C) by the application of exogenous ABA, desiccation, light exposure, and an experimental cryoprotectant (GLK 8908). Electrolyte leakage, elastic and plastic bend angles, and stem elongation were used to evaluate freezing injury, cell wall rigidity, and growth, respectively. The role of extensin, a structural hydroxyproline-rich glycoprotein suspected of being involved in cell changes during acclimation, was examined using the hydroxylation inhibitor ⍺,⍺’-dipyridyl. Exogenous ABA application and drought stress decreased freezing injury by approximately a 10% -6°C compared to controls. In one experiment light was found to be more effective than ABA at acclimating peas at warm temperatures. Foliar application of GLK 8908 decreased freezing injury (30% at -6°C). Stem bendability was not correlated with freezing resistance. ABA treated peas grown in the dark had reduced growth rates and increased stem rigidity, but exhibited greater injury at -6°C than untreated dark grown peas. Extensin content was not related to cold hardiness. Although acclimation of ’Alaska’ peas did occur at warm temperatures with various treatments the reductions in freezing injury were minor when compared to plants acclimated by exposure to low temperatures. GLK 8908 was also evaluated for its effects on ’Alaska’ pea survivability and yield. Peas treated with GLK 8908 (1 and 10% aqueous) and subjected to a -6.7°C freeze were found to have increased survival without significant changes in days to first flower, leaf surface area/plant, and yield/plant. / Master of Science

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