Structural forensic engineering is a topic that has traditionally been approached in a deterministic manner. This thesis explores the use of probabilistic procedures as a tool to obtain more objective and realistic results in forensic investigations. The first goal of the thesis is the identification of the most probable cause of a structural failure using probabilistic procedures. The second goal is to develop a procedure to qualify forensic engineers and experts according to their qualifications. / In the first part, the basic qualifications required for a forensic engineer or expert are compiled in a checklist and attributed individual scores, the sum of which qualifies a candidate to act as a forensic engineer or expert. The proposed qualification and scoring checklist is then validated through a survey conducted among professionals with forensic engineering exposures. / The second part quantifies failure modes in terms of their likelihood. The proposed methodology uses a-priori failure probabilities from historic data, elicits forensic engineering experts for subjective failure probabilities, calculates the updated posterior failure probabilities, and identifies the failure cause corresponding to the highest posterior probability as the most plausible cause of failure. / The proposed methodology is supported by a thorough literature review of forensic engineering procedures, a classification of structural failure causes, and expert opinion elicitation and aggregation methods.

This work addresses issues for improving the estimation of the recurrence rate and the distribution in severity of extreme ice events in the Montreal area, which is required in order to determine design criteria for structures such as electric transmission lines. Some of the limitations of current methods for studying extreme freezing rain events are due to the relatively short data records. This results in variability of 'at site' data sets that have only a few large accumulations. The methods developed in this work address these issues. First, de-aggregated analysis is used to obtain better statistical fits by grouping storms according to physical variables that are correlated with the occurrence of ice storms (spatial patterns of sea level pressure (SLP) or 1000 to 500 hPa geopotential height anomalies). And second a procedure to decrease the uncertainty on estimates of the hazard function at high return periods based on solving the CRREL Simple icing model using reliability method is developed. In this procedure, uncertainty is propagated through the model by treating it as a function of random variables. / Anomaly maps of several meteorological variables were investigated for the objective categorization of ice storms. The NCEP reanalysis data was used to compile spatial patterns for the analysis of the storms identified and categorized by Rauber et al (2001). Several multivariate statistical analysis procedures were used to investigate the effectiveness of sea level pressure, the 1000 to 500 hPa, and the 1000 to 925 hPa geopotential heights for clustering these storms. Results indicated that the k-means algorithm applied to principle component scores of the storm anomaly maps provided the best clustering results. The results indicated that storms with higher precipitations belong to a group associated with the phenomena of cold air damming as a result of the Appalachian Mountains. / Environment Canada hourly data was used to identify freezing rain events and obtain measurements of wind speed and precipitation during the events that occurred over Ottawa, Montreal, and Quebec City. General Pareto or Generalized Extreme Value distributions are fitted to the data of total precipitation or total radial ice accumulation for each cluster using a peaks-over-threshold approach. Statistical tests indicate the resulting distributions for precipitation are significantly different from each cluster. This de-aggregated approach improves estimates of the icing hazard by improving statistical fits and by reducing the sensitivity of the results to the choice of threshold. / The second approach used to improve the estimates of the icing hazard function, using reliability methods, considers total precipitation, freezing ratio, and wind speed as the random variables in solving the icing model. The most likely combination of variables associated with high ice accumulations was found to high total precipitation, high freezing ratios, but only slightly higher than average wind speed. The latter is useful for defining load combinations (wind speed and ice accumulation) for structural design purposes. / Finally, the superstation approach of Jones and White (2002a) was investigated by combining Environment Canada data for Ottawa, Montreal and Quebec City. Monte Carlo simulations were performed on the regional set of data using 'at site' indexes. The reliability analysis of empirical icing equation produced results similar to Jones and White at quantiles associated with the 50 year return period. However there were greater differences at higher quantiles. The estimated return periods for radial ice accumulations of 45mm are 160, 210, and 85 years for Montreal, Ottawa, and Quebec City respectively. / L'objectif de ce travail est d'améliorer l'estimation du taux de récurrence et la distribution de la sévérité des tempêtes de verglas dans la région de Montréal ; deux quantités requises pour déterminer les critères de conception de certaines structures, telles que les lignes de transmission, pour ce type d'événement. Certaines des faiblesses des méthodes actuelles pour étudier les événements de pluies verglaçantes sont liées à la disponibilité limitée de données. Cela se traduit par des observations variables et un faible nombre d'événements importants. Les méthodes développées dans ce travail adressent ces problèmes. En premier lieu, une analyse désagrégée est employée afin d'obtenir de meilleures tendances statistiques en regroupant les tempêtes en fonction de différentes caractéristiques physiques qui sont reliées aux événements de verglas. Une deuxième procédure pour diminuer l'incertitude reliée à l'estimation de la période de récurrence des événements extrêmes est basée sur la solution du modèle d'accumulation CRREL à l'aide de méthodes d'analyse fiabilistes. / Les données de réanalyse du NCEP ont été utilisées pour compiler les relations spatiales entre les paramètres météorologiques pour les tempêtes identifiées et classifiées par Rauber et al. (2001). Plusieurs analyses statistiques à variables multiples ont été utilisées afin d'évaluer l'efficacité de le pression au niveau de la mer, de l'épaisseur de la couche atmosphérique entre 1000 et 500 hPa et de l'épaisseur de la couche atmosphérique entre 1000 et 925 hPa à regrouper les tempêtes. Les résultats indiquent que l'algorithme k-means couplé avec une représentation par composantes principales des tempêtes produit les meilleurs résultats. Les tempêtes avec des précipitations plus élevées sont associées à un groupe où les systèmes de haute pression sont ralentis ou stoppés momentanément par les Appalaches. / Les observations d'environnement Canada ont été utilisées pour identifier les tempêtes de verglas qui ont affecté Ottawa, Montréal et Québec et obtenir un échantillon de la vitesse des vents et des précipitations. Les précipitations totales et l'accumulation de verglas pour chaque groupe sont représentées par les distributions General Pareto et Generalized Extreme Value, en combinaison avec une approche Peaks over Treshold. Les distributions obtenues diffèrent de façon importante pour les différents regroupements. L'approche par désagrégation améliore la performance des modèles et est moins sensible au choix des précipitations minimales (le treshold). / La seconde approche pour l'estimation de la période de retour des événements de verglas extrêmes considère la précipitation totale, la proportion du gel et la vitesse du vent comme des variables aléatoires dans le modèle d'accumulation de verglas. La combinaison la plus probable des variables associée à des accumulations de verglas importantes correspond à une précipitation totale et une proportion de gel élevées, mais une vitesse du vent seulement légèrement plus haute que la moyenne. Cette information est utile à l'identification des cas de combinaison des charges (vitesse de vent et accumulation de verglas) pour les critères de conception. / Finalement, la méthode des super-stations (Jones and white 2002a) a été analysée pour un échantillon regroupant les villes d'Ottawa, Québec et Montréal. Des simulations Monte Carlo ont été effectuées sur les données régionales et cette approche fiabiliste, appliquée au modèle empirique d'accumulation, donne des résultats similaires à ceux de Jones et White (2002a) pour une période de retour de 50 ans, mais les divergences sont plus importantes pour des périodes de retour plus élevées. Les périodes de retour correspondant à une accumulation de verglas de 45mm pour Montréal, Ottawa et Québec sont de 160, 210 et 85 ans, respectivement.

Low-rise buildings, constructed using wood, are vulnerable to extreme wind storms and earthquakes. While several experimental measurements of the environmental loads (mostly wind) on the building envelope have been made at full scale, none of these studies directly linked these external loads with the internal forces and displacements of the structure, as achieved in this research. / The thesis presents the experimental and analytical work on two light-frame wooden structures, where one already existed (Forintek shed in Quebec City) and the other (UNB house) was built specifically for the research project on the University of New Brunswick campus in Fredericton. The research goal was to devise and demonstrate methods of identifying load paths in light-frame wood buildings subject to environmental loads. The objectives were also to improve the knowledge on the magnitude of the forces generated by environmental loads on typical low-rise buildings; to measure forces and deformations in test buildings and correlate them with the applied loads; and finally to develop accurate numerical whole-building structural models. / These goals were achieved by carrying out experiments at the element level (studs, sheathings), subsystem level (shear walls) and on the whole-building level (finished and "realistic" light-frame timber buildings). The responses of these buildings to controlled static tests as well as natural environmental loads were observed and compared with a wind tunnel study and with detailed finite element models with good agreement. / Shear walls were tested in isolation and as a part of the whole structure. The tests indicated that neither the strength nor the stiffness decreased by the same magnitude as the wall effective length is reduced. Therefore, the simple concept of effective length, being used presently, is invalid. / For the Forintek shed, the structural monitoring was based on measurements of deformations within a representative segment of the wall and roof surfaces and a matching grid of wall and roof wind pressure taps supplemented with a wind tunnel study at Concordia University. In general, it was shown that the building surroundings had a great effect on the pressure distribution of the surface on the structure and that these effects are cannot always be determined intuitively. Both mean and peak pressure coefficient were measured and they compared well with corresponding values obtained in the wind tunnel tests. In general, the peak pressure coefficients from the full-scale tests were higher than those obtained from the wind-tunnel tests. / The results from controlled static loads on the UNB house indicated that the load was distributed to all walls, and significant load sharing was observed. Mostly, this reflected not only the rigidity of the roof, but also the rigidity of transverse walls. The stiffness of the roof was sufficient to distribute load to walls farthest away from the load application point. Also, the expected vertical paths for load were not observed. It was also found that the internal forces are concentrated near the corners of the building. Under vertical loading on the roof, the load at the roof-to-wall interface was concentrated in a small region of the building plan around the application point. This was not the case at the superstructure-to-foundation interface. The test results also showed that the load was transferred to the transverse walls, even though there were only nominal connection between the wall and the roof trusses. / The results from the analytical modeling showed good agreement with the full-scale test results for shear walls as well as for the whole building. The 3-D model was able to simulate the sharing of racking forces between shear walls, based on experiments reported in the literature. It was also able to reproduce static test results and predict the force measurements obtained from load cells underneath the house structure. In general, the errors in the numerical prediction were small. The model was able to predict the interaction between the roof system and the walls and the interactions amongst walls. / The research relied on the collaboration of several researchers in industry and academia, and was funded by a CRD grant of the Natural Sciences and Engineering Research Council of Canada.

The Lindsay Formation located in southern Ontario has been selected as a site for the construction of a deep geological repository for low to intermediate level nuclear waste. In order to prevent the migration of any radionuclides escaping the engineered barriers within the repository, the underlying material, Lindsay Limestone, must also be treated as an additional barrier. This thesis examines the use of hydraulic pulse testing in order to estimate the permeability of Lindsay Limestone. Tests are performed on 100 mm diameter samples cored both perpendicular to and along the bedding planes. The samples are subjected to isotropic confining stresses that are cycled from 5 MPa to 20 MPa resulting in a seven times increase in permeability perpendicular to the bedding plane, and a slight decrease parallel to the bedding plane. Including the recorded alterations, permeability estimates all remain ≤10^-22 m^2 showing that the material is a good candidate for a geological repository. / La Formation Lindsay, qui se trouve au sud-est de l'Ontario, a recemment été selectionée pour la construction d'un repositoire souterrain de dechets nucleaires. Puisque les elements radionucleaires sont entreposé sous la terre, leur migration est normalement empechée en utilisant des barrieres artificielles. Cela dit, pour créer un projet qui sera efficace pour la demi-vie des isotopes radioactives, de 50 000 a 100 000 ans, il faut aussi considérer la formation de roches sous le site comme étant une barriere additionelle. Cette thèse examine l'utilisation des tests de pulsion hydraulique pour estimer la perméabilitée de la Roche Calcaire Lindsay. Les tests ont été faits sur des cylindres ayant un diametre de 100 mm. Ces cylindres ont été prélevés de la roche dans la direction parallèle au plan de stratification ainsi que perpendiculairement cette direction. Durant les tests, les specimens ont été sujet a des pressions uniformes qui ont été variées de 5 MPa a 20 MPa. Ceci a causé une augmentation de la permeabilitée dans les spécimens perpendiculaires au plan de sratification d'environ 7 fois la permeabilitée originale, et une petite diminution de la permeabilitée dans la direction des plaines de déposition. Malgré les changements aux valeurs de la perméabilitée dans les spécimens, ces valeurs sont restées ≤10^-22 m^2, ce qui indique que le site est idéal pour la construction d'un repositoire souterrain.

Pervious concrete is an innovative material with several environmental advantages. Studies on the properties and performance of ordinary Portland cement (OPC) pervious concrete have been done worldwide. Portland limestone cement (PLC) has recently been introduced into the Canadian market as a greener option than OPC. This thesis explores the possibility of using PLC in pervious concrete to achieve technical and environmental benefits.Since the major application of pervious concrete is pavements, it is important to find a way to accelerate the concrete curing process, as one of the most important factors in determining the cost and impact of road work is the construction time. Pervious concrete is the ideal material to cure by carbonation in a feasible way. It is usually designed without reinforcement, so the reduction of the concrete pH value resulting from the process has no impact. Additionally, the open massive pore structure provides a larger surface to optimize CO₂ penetration during the curing process. This study focuses on the effect of carbonation on early age strength and freezing and thawing durability of PLC pervious concrete. It was found that, under the same conditions, PLC pervious concrete shows lower compressive strengths and higher absorption than the OPC counterpart. The optimization of the mixture proportion by including admixtures would permit the use of PLC to generate a pervious concrete with strengths equivalent to OPC pervious concrete. Carbonation curing of PLC pervious concrete increased early age compressive strength, and maintained a comparable final strength. In addition, carbonation curing increased resistance to absorption, but decreased the resistance to freezing and thawing cycles in saline solution. Therefore, carbonation curing of pervious concrete is not recommended for cold climates. / Le béton drainant est un matériau innovant avec plusieurs avantages environnementaux. Des études portant sur les propriétés et la performance du béton drainant au ciment Portland ordinaire (CPO) ont été réalisées internationalement. Le ciment Portland au calcaire (CPC) a fait son arrivée sur le marché canadien récemment et s'avère une option plus écologique que le CPO. Cette thèse explore la possibilité d'utiliser CPC en béton drainant pour obtenir avantages techniques et environnementaux. Une des applications majeures du béton drainant est le pavage. Pour cette raison, c'est important de trouver une façon d'accélérer le processus de durcissement du béton, puisque le temps de construction est l'un des facteurs les plus importants déterminant le coût et l'impact des travaux routiers. Le béton drainant est le matériau idéal à mûrir au carbone de manière faisable. Il est fabriqué sans armature et donc, la réduction du pH du béton résultant du processus de carbonatation n'a aucun impact. De plus, la structure ouverte massive des pores offre une surface plus grande permettant d'optimiser la pénétration de CO₂ au cours du processus de mûrissement. Cette étude a pour but de déterminer l'effet de la carbonatation sur la résistance à jeune âge et la durabilité au gel/dégel du béton drainant fabriqué avec le CPC. Les résultats indiquent que, pour les mêmes conditions, il y a une réduction de la résistance à la compression et une meilleure absorption avec le béton drainant au CPC comparé avec ceux au CPO. L'optimisation du dosage par l'inclusion d'ajouts cimentaires et chimiques, permettrait l'utilisation du CPC pour générer un béton drainant avec des résistances équivalentes au béton drainant au CPO. Le mûrissement au carbone du béton drainant au CPC a augmenté la résistance à la compression à jeune âge, et a maintenu une résistance finale comparable. De plus, le mûrissement au carbone a augmenté la résistance à l'absorption, mais a réduit la résistance aux cycles de gel/dégel en solution saline. Par conséquent, le mûrissement au carbone du béton drainant n'est pas recommandé pour les climats froids.

There is now a broad scientific consensus that the global climate is changing in ways that could have a profound impact on human society and the natural environment over the coming decades. In particular, changes in the frequency and magnitude of extreme temperatures are likely to have more substantial impacts on the environment and human activities than changes in the mean temperature. The present study is therefore addressing three main objectives: (a) to propose a systematic data analysis method for characterizing the variability of daily extreme temperatures at different sites; (b) to develop new statistical downscaling models that could accurately describe the linkage between large-scale climate variables and the characteristics of temperature extremes at a local site; and (c) to develop a stochastic method for simulating accurately the extreme temperature processes. / Firstly, a systematic data analysis procedure was proposed for analyzing the variability of daily maximum (Tmax) and minimum (Tmin) temperature characteristics. The suggested procedure consists of performing a detailed statistical analysis of twelve relevant temperature indices that are important for various practical application purposes: mean of diurnal temperature range, frost season length, growing season length, freeze and thaw cycle, 90th percentile of Tmax, 10th percentile of Tmin, means and standard deviations of Tmax, Tmin, and the daily mean temperature. The suggested method was applied to the analysis of daily Tmax and Tmin data for 20 stations in Quebec. The available records used are different from station to station, varying from 44 years to 107 years. In general, it was found that, depending on the temperature index considered as well as on the particular season of the year, there are some significant increasing or decreasing trends at some locations in Quebec. Results of this analysis would provide valuable information on the temporal and spatial variations of daily extreme temperature processes in the region. Furthermore, it can be observed that no systematic spatial variability of the increasing or decreasing trends of any of the twelve temperature indices considered could be identified for a given area in Quebec. / Secondly, two new statistical downscaling models were proposed using the stepwise and robust regression methods in order to describe the linkage between largescale climate variables and the characteristics of Tmax and Tmin at a local site. The performance of these two models was tested using daily extreme temperature data available at Dorval Airport station in Quebec and the NCEP data for 25 different climate variables for the 1961-1990 period. It was found that the proposed stepwise and robust regression downscaling models can provide accurate estimates of fundamental statistical and physical properties of Tmax and Tmin. In addition, it has been observed that three climate variables, the mean sea level pressure, the 850hPa-geopotential height, and the near surface specific humidity, had the most significant effect on Tmax and Tmin at Dorval Airport. Furthermore, as compared with the popular SDSM model, the stepwise and robust regression models can provide more accurate estimates of the local Tmax and Tmin characteristics. In particular, the robust regression model was found to be the most accurate. / Finally, a new stochastic simulation procedure was developed in this study for simulating the Tmax and Tmin temperature time series at a local site using the combination of the first-order autoregressive AR(1) model and the SVD technique. Results of the evaluation of the proposed AR(1)-SVD simulation method using daily extreme temperature data at Dorval Airport for the 1961-1990 period have indicated the feasibility of this method in describing accurately the observed basic statistical properties (mean, standard deviation, and first order autocorrelation) of the daily Tmax and Tmin time series at a local site.

Steel slag is a major by-product of the steel industry, with a production of nearly 300 kg for every tonne of steel produced. It has been conventionally used as an aggregate in road base construction, but this use has been limited due to the high free lime content, which causes volume expansion problems. This thesis explores the feasibility of using CO2 activation to eliminate free lime and develop strength for a steel slag-based building product. The CO2 activated steel slag has the potential to be used as cementing material to replace Ordinary Portland Cement (OPC) and to sequester carbon dioxide through activation. The technology can show numerous technical and environmental benefits, while minimizing the embodied energy in the final products.Compressive strength and carbon uptake of compacts made of KOBM1, KOBM2, ladle and GGBF slag were evaluated in comparison with counterpart OPC compacts. KOBM slag showed the greatest potential, with compressive strength and carbon uptake values comparable to OPC. The microstructural change of carbon dioxide activated KOBM slag was assessed in detail by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Its durability was also measured by the means of an accelerated water softening test. The wallboard made of KOBM slag bonded with sawdust was fabricated, and its mechanical performance was found to be competitive to commercial cement-based wall-boards. The research demonstrates that certain types of steel slags can be successfully activated by carbon dioxide in the production of commercial products to replace OPC. / Le laitier d'acier est un important coproduit de l'industrie de l'acier ayant une production près de 300 kilogrammes pour chaque tonne d'acier produite. Il est traditionnellement utilisé pour la construction d'infrastructure routière, étant ajouté comme additif dans le ciment et les agrégats. Cependant la forte présence de chaux libre dans les résidus de métallurgie cause une expansion de volume lors de son utilisation comme matériau de construction, ce qui limite son application dans l'industrie.Cette thèse explore la possibilité d'éliminer la chaux libre par l'activation de la réaction chimique du CO2 ainsi développer la résistance pour un produit de construction à base de laitier d'acier. L'activation du dyoxide de carbone présent dans le laitier d'acier a le potentiel d'être utilisé comme matériau cimentière au lieu du ciment Portland ordinaire en plus de séquestrer le CO2 grâce à son activation. Cette technologie peut démontrer de nombreux avantages techniques et environnementaux, tout en minimisant l'énergie intrinsèque des produits finaux.Des essais pour quatre différents types de scories compactes, formées à partir de KOBM1, KOBM2, et de scories de GGBF ont été realisés afin de tester leur capacité d'absorption de carbone et leur résistance à la compression. Les résultats ont été comparés avec des spécimens homologues produits avec du ciment Portland ordinaire. Le changement microstructurel du laitier KOBM avec CO2 activé a été évalué en détail par diffraction des rayons X, TGA et SEM. Sa durabilité, par un essai de résistance à l'eau a également été mesurée. Des plaques de plâtre à base de laitier d'acier KOBM liés avec de la sciure de bois ont été fabriquées, leur performance mécanique s'est avérée tout à fait comparable à celle des plaque de plâtres en ciment offertes sur le marché. Finalement, la recherche conclut que l'activation du dioxyde de carbone de certains produits commerciaux, faits à base de laitier d'acier, peuvent être utilisés et permette l'emploi du laitier d'acier pour remplacer le ciment Portland ordinaire dans certains produits commerciaux.

Unreinforced masonry (URM) infill walls are widely used in structures in North America. In several "pre-code" hospital buildings constructed before the 1970s, terra cotta masonry blocks have been used extensively. Although unreinforced terra cotta infill walls play a structural role, interior partitions are generally considered as non-structural components (NSCs) and their stiffness effects on the structure are often ignored in seismic analysis and design, while their weight/mass is included as uniformly distributed load/inertia. Terra cotta infill walls interact with their bounding frame during earthquakes and increase the lateral stiffness and strength of the structure, which in turn influences the dynamic response of the building. In situ vibration measurements and observations of past earthquake-induced damage clearly demonstrate the necessity of considering the effect of infill walls on structural response, particularly for post-critical buildings such as hospitals which have to remain functional after severe design-level seismic shaking. To illustrate the structural contribution of infill terra cotta walls, two eleven-storey buildings have been selected which are two wings (Blocks #7 and #8) of CHU Sainte-Justine, a paediatric research hospital located in Montréal, Canada. This hospital campus was initially built in the late 1950s and Block #7 was seismically retrofitted in 2008 by adding a full-height reinforced concrete shear wall at its free end and connecting the other end of the building to the adjacent Block #9, using structural anchor bars at each floor slab and along the height of interfacing columns. Block #8 was not retrofitted and has remained unattached to adjacent Block 9. A detailed linear elastic finite element analysis model of each building was created where the infill unreinforced terra cotta walls have been modeled. Only linear models were created at this stage as the hospital buildings have to remain practically linear elastic to fulfill their functionality performance objectives. Two different techniques were adopted for modeling these infill walls, namely using panel elements and compression strut models. For the compression strut models, three different formulas suggested in the literature were used to calculate the effective width and properties of the strut. In parallel, in situ Ambient Vibration Measurements (AVMs) were done in both buildings and their dominant dynamic properties have been extracted using two different operational modal analysis techniques. The AVM results were used for validation and also calibration of the numerical models. The calibrated models were subjected to a set of 12 synthetic ground accelerograms compatible with the NBC Uniform Hazard Spectra (UHS) for Montréal in both principal horizontal directions independently. Selecting two floors in each block (top floor #7 and middle floor # 3), Floor Response Spectra (FRS) and Interstorey-Drift curves were developed for each record. The effects of seismic rehabilitation and presence of infill walls on the dynamic properties of the building and also on the performance of their NSCs were addressed by comparing the results of different models. Finally, a detailed study of the NSC's seismic behaviour was done using FRS and Interstorey-Drift curves provided for the two selected floors. Finally, the lateral stiffness of the rehabilitated block # 7 is significantly improved compared to block # 8 which means it is subjected to larger accelerations; for example the maximum acceleration at the 7 floor is on average three times the acceleration of the same floor in block # 8 for the twelve earthquake scenarios. The non-structural components that are sensitive to accelerations are subjected to higher forces in block 7. Since the inter-storey drifts are much reduced in block 7 to very low values justifying the linear analysis, the performance of architectural components and functional components connected at several levels is improved. / Les murs en maçonnerie non armée (MNA) sont très présents dans les bâtiments nord-américains. Dans plusieurs hôpitaux « pré-code » construits avant l'adoption des normes parasismiques dans les années 1970, la maçonnerie de blocs en terra cotta a été abondamment utilisée. Bien que les murs de remplissage jouent effectivement un rôle structural dans la réponse sismique des bâtiments, les murs qui servent simplement de cloisons internes sont considérés comme des composants non-structuraux et leur influence structurale est négligée dans les analyses sismiques. Les murs de remplissage en terra cotta interagissent avec leur cadre périphérique durant les séismes et augmentent la rigidité latérale et la résistance des ossatures, ce qui influence directement leur réponse dynamique. Observations de dommages lors de séismes antérieurs ont prouvé la nécessité de tenir compte de l'influence structurale des murs de remplissage, particulièrement pour les bâtiments de protection civile comme les hôpitaux qui se doivent de rester fonctionnels suite au séisme de conception.Cette thèse illustre la contribution structurale de murs de remplissage en terra cotta à l'aide d'une étude de cas détaillée de deux bâtiments de onze étages du Centre hospitalier universitaire (CHU) Sainte-Justine – les blocs #7 et #8, un hôpital pédiatrique situé sur l'île de Montréal. Cet hôpital a été construit à la fin des années 1950 et le bloc #7 a fait l'objet d'une réhabilitation parasismique en 2008. Le bloc #8, par contre, n'a subi aucune réhabilitation parasismique et demeure non-relié à son bâtiment adjacent. Un modèle détaillé pour l'analyse par éléments finis de chacun des deux blocs a été mis au point, avec modélisation des murs de remplissage en terra cotta. Seuls des modèles linéaires élastiques ont été créés pour cette étude considérant que les bâtiments doivent rester pratiquement en mode de réponse linéaire pour satisfaire leur objectif de performance sismique. Deux techniques ont été appliquées pour la modélisation des murs de remplissage : la définition de panneaux continus et la méthode des bielles comprimées équivalentes.En parallèle avec ces études numériques, une campagne de mesures de vibrations ambiantes a été réalisée pour les deux blocs et les propriétés dynamiques dominantes des bâtiments ont été identifiées, L'analyse des mesures s'est faite à l'aide de deux techniques d'analyse modale opérationnelle en sélectionnant les pics des fonctions obtenues par décomposition des mesures dans le domaine des fréquences, soit la méthode de base(FDD) et une version dite améliorée (EFDD). Les résultats des mesures de bruit ambiant ont été utilisés pour valider et calibrer les modèles numériques. Une fois calibrés, les modèles ont été analysés sous l'effet de 12 séismes représentés par des accélérographes synthétiques. Deux étages spécifiques ont été sélectionnés: le plancher du 7e étage et le plancher du 3e étage. Les spectres de réponse de ces planchers ainsi que les historiques des déplacements inter-étages (7-8) et (3-4) ont été générés.L'étude comparative des résultats obtenus avec les différents modèles d'analyse par éléments finis (i.e. excluant et incluant les murs de remplissage) a permis d'étudier les effets de la réhabilitation parasismique du bloc #7 et l'influence de la présence des murs de remplissage dans les blocs #7 et #8 sur leurs propriétés dynamiques. Finalement, les analyses sismiques ont permis de quantifier l'influence de ces effets sur le comportement des composants non-structuraux en comparant les spectres de planchers et les déplacements inter-étages. Au final, le bloc réhabilité a considérablement amélioré sa rigidité et par le fait même subit des accélérations de beaucoup supérieures à celles du bloc 8 non réhabilité. Par contre, les déplacements inter-étages sont réduits à des valeurs très faibles, ce qui améliore la performance des composants architecturaux et des composants fonctionnels connectés à plusieurs niveaux.

This study focuses on analyzing the interaction between Portland type I cement and motor oil, and its influence on the hydration of the cement. The Portland type I cement was tested by using a Viscosity meter, a Zeta potential meter and by Fourier Transform infrared spectroscopy (FTIR). The tested samples containing increasing concentration of motor oil were subjected to Viscosity, Zeta potential and Infrared spectroscopy (IR) tests. Ultimate compressive strength (UCS) and Chemical oxygen demand (COD) tests, which signify the leachability of the oil from the cement, are also included. The results show that oil (1) retards hydration, (2) reduces bonding in the cement, and (3) leaches from the hydrated cement. / The presence of calcium silicate polymerization, indicated by the appearance of Si-H, CO3-2, and SiO4 -4 after 90 minutes of hydration, shows that cement hydration was inhibited both by oil and by one freeze-thaw cycle. (Abstract shortened by UMI.)

The behaviour of interior slab-column connections in flat plates is investigated. The first part of this thesis discusses six two-way slab-column specimens which were designed such that they would fail in punching shear. The parameters investigated were the use of high-strength concrete and the concentration of the slab flexural reinforcement in the immediate column region. The effects of these parameters on the punching shear capacity, negative moment cracking, and stiffness of the two-way slab specimens are investigated. / The second part of this thesis is a comparison of the test results obtained from this experimental program with the punching shear predictions of the Canadian CSA A23 3-94 Standard and the American ACI 318-95 Code. Some comparisons of the punching shear strength provisions of the British BS 8110-85 Standard and the European CEB-FIP 1990 Model Code are also carried out. Furthermore, the CSA Standard and the ACI Code predictions are compared to the experimental results obtained from some slab-column connections tested in this experimental program and tested by various investigators. / The beneficial effects of the use of high-strength concrete and of the concentration of flexural reinforcement in the immediate column vicinity are demonstrated. It is also concluded that the punching shear strength of slab-column connections is a function of the flexural reinforcement ratio and that the shear design of slabs according to the current Canadian and American codes can be unconservative under certain conditions. It is recommended that the punching shear expressions of the CSA Standard and the ACI Code be modified to include the effect that the flexural reinforcement ratio has on the shear capacity of slab structures.