In this study, the energy conservation potential of selected retrofitting interventions on an office building were investigated, on the basis of which some rational strategies for the improvement of building envelopes in terms of energy, environment and comfort design were proposed. Examined were various measures on envelope constructions that can be retrofitted to existing buildings. By using simulation techniques, the effectiveness of such measures in reducing energy consumption and environmental threat were also assessed. Effects of glazing types, effect of insulation and thermal mass were analyzed as energy efficient retrofit measures to the Engineering Building (MM building) situated on Middle East Technical University Campus, Ankara. The Energy-10 computer program was used for the modeling and simulation of the energy flows through the envelope to examine measures for reducing thermal load. Within this framework, the energy conservation potential of single and combined retrofitting actions was investigated. Based on results from the evaluation model, it was found that a saving of 161.20 MWh in the annual heating load could result, depending on the glazing type. The evaluation showed that thermal insulation is the most effective factor in thermal performance when placed as an exterior layer on walls. The study showed thermal mass has significant impact on increasing the duration, where highest temperatures were achieved, under passive mode. The study also revealed that applying a combination of retrofitting measures which responded to the challenges and opportunities presented by different fa&ccedil / ade orientations, a saving of 52.41% can be achieved in annual heating energy use in case study building.

About half of the building stock in Turkey is masonry type and one fourth of the building stock is one-storey brick type masonry buildings. Especially the rural masonry houses are commonly constructed by their own residents without any engineering knowledge. Traditional masonry houses usually have heavy roofs which generate large lateral forces on walls during earthquakes. Readily available retrofitting techniques are mostly complicated and costly making it not feasible for uneducated poor residents to strengthen their own houses. The aim of this thesis is to develop a new alternative strengthening technique using scrap tires that is economic and easy to apply on the walls of one-story masonry houses. In order to investigate the usage of scrap tires for masonry wall post-tensioning, forty three scrap tire rings (STRs) from nine different brands and nine rim-rings direct tension experiments were conducted. The average tensile load capacities of STRs and rim-rings were found as 132.6 kN and 53 kN, respectively. Six strip walls (i.e., four brick- and two briquette-walls) strengthened by applying post-tensioning loads with STCs and hybrid system were tested in out-of-plane bending direction. The out-of-plane capacity of the brick and briquette walls increased up to about 9 times and 5 times with respect to their nominal capacities, respectively. Finally, two-full scale traditional masonries were tested by the tilting table. The capacity of strengthened house increased 75% with respect to the unstrengthened one. The results obtained form the conducted tests are highly promising and suggest that the method can be used as a low-cost and simple strengthening technique for seismically deficient single storey, masonry type houses.

Στόχος της παρούσας διατριβής είναι η εξαγωγή συμπερασμάτων σχετικά με την απόκριση πολυώροφων κατασκευών ενισχυμένων με εμφάτνωση από οπλισμένο σκυρόδεμα και η αναλυτική προσέγγιση αυτών υπολογίζοντας τις χαρακτηριστικές ιδιότητες δυσκαμψίας, αντοχής και ικανότητας παραμόρφωσης του νέου τοιχώματος. Βεβαίως, ελέγχεται και η επίτευξη μονολιθικής σύνδεσης μεταξύ φατνώματος και μελών του περιμετρικού πλαισίου. Για το λόγο αυτό, κατασκευάζεται και δοκιμάζεται πειραματικά μέσω της υβριδικής μεθόδου με υποκατασκευές, ένα τετραώροφο πλαίσιο εμφατνούμενο από οπλισμένο σκυρόδεμα εξασφαλίζοντας την επαρκή σύνδεση του κορμού του τοιχώματος με το υφιστάμενο πλαίσιο. Ακολουθεί η διεξαγωγή μη - γραμμικής δυναμικής ανάλυσης προκειμένου να υπάρξει προσέγγιση των πειραματικών αποτελεσμάτων από τα αναλυτικά, καθώς και ο υπολογισμός των χαρακτηριστικών παραμορφώσεων και δυσκαμψίας του δοκιμίου σύμφωνα με τον Κανονισμό Επεμβάσεων (ΚΑΝ.ΕΠΕ.)και την υιοθέτηση ορισμένων παραδοχών, η αξιοπιστία των οποίων εξετάζεται μέσω της αναλυτικής προσέγγισης εναλλακτικού πειραματικού φορέα. / The aim of this thesis is to reach in conclusions about the response of existing multistorey reinforced concrete structures, retrofitted by reinforced condrete infill wall and also analytically approach that response computing the characteristic properties of stiffness, strength and deformation capacity of the new composite wall. Moreover, the effectiveness of the connection between the web and the surrounding frame members is under investigetion. For the aforementioned purposes, a 4-storey RC frame converted into slnder wall is constructed and tested by pseudo-dynamic method with substructures. In order to compare the experimental with the analytical results, a non-linear dynamic analysis is conducted and the deformation and stiffness of the specimen are determined by the use of some computtional assumptions, which derive from the computational procedure of the characteristic response parameters of the composite wall. Finally, the overall reliability and correctness of those assumptions is examined through the analytical procedure of a different exprimental project.

In recent decades, a significant research has been carried out towards understanding the behaviour of plated beam. Initially designed to achieve a desired capacity, the plated beams prematurely fail in undesirable modes of failure, such as debonding and peeling. The uncertainty related with such modes of failure poses a real challenge towards quantifying them. This field is far from being clearly understood. Therefore, an attempt is made in this thesis to accurately predict the behaviour of adhesively plated beams.

abstract: Civil infrastructures are susceptible to damage under the events of natural or manmade disasters. Over the last two decades, the use of emerging engineering materials, such as the fiber-reinforced plastics (FRPs), in structural retrofitting have gained significant popularity. However, due to their inherent brittleness and lack of energy dissipation, undesirable failure modes of the FRP-retrofitted systems, such as sudden laminate fracture and debonding, have been frequently observed. In this light, a Carbon-fiber reinforced Hybrid-polymeric Matrix Composite (or CHMC) was developed to provide a superior, yet affordable, solution for infrastructure damage mitigation and protection. The microstructural and micromechanical characteristics of the CHMC was investigated using scanning electron microscopy (SEM) and nanoindentation technique. The mechanical performance, such as damping, was identified using free and forced vibration tests. A simplified analytical model based on micromechanics was developed to predict the laminate stiffness using the modulus profile tested by the nanoindentation. The prediction results were verified by the flexural modulus calculated from the vibration tests. The feasibility of using CHMC to retrofit damaged structural systems was investigated via a series of structural component level tests. The effectiveness of using CHMC versus conventional carbon-fiber reinforced epoxy (CF/ epoxy) to retrofit notch damaged steel beams were tested. The comparison of the test results indicated the superior deformation capacity of the CHMC retrofitted beams. The full field strain distributions near the critical notch tip region were experimentally determined by the digital imaging correlation (DIC), and the results matched well with the finite element analysis (FEA) results. In the second series of tests, the application of CHMC was expanded to retrofit the full-scale fatigue-damaged concrete-encased steel (or SRC) girders. Similar to the notched steel beam tests, the CHMC retrofitted SRC girders exhibited substantially better post-peak load ductility than that of CF/ epoxy retrofitted girder. Lastly, a quasi-static push over test on the CHMC retrofitted reinforced concrete shear wall further highlighted the CHMC's capability of enhancing the deformation and energy dissipating potential of the damaged civil infrastructure systems. Analytical and numerical models were developed to assist the retrofitting design using the newly developed CHMC material. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2013

Le parc de bâti ancien représente un potentiel d’économies d’énergie avéré. Cependant, sa diversité et certaines caractéristiques des matériaux d’enveloppe gênent la mise en place de stratégies de réhabilitation efficaces. Parmi ce patrimoine, les maisons individuelles en pierre calcaire présentent des problématiques spécifiques vis-à-vis de la réhabilitation. Le tuffeau, plus spécifiquement, est une pierre calcaire à forte porosité dont la particularité est la facilité avec laquelle il se gorge d’eau. Ses propriétés hygrothermiques sont alors impactées et le matériau se dégrade. Par ailleurs, ce bâti bénéficie de températures intérieures confortables en été et de qualités architecturales certaines. Il s’agit là de contraintes à considérer lors de la réhabilitation énergétique de ces bâtiments. Les solutions proposées doivent donc répondre à des objectifs parfois divergents. Pour le patrimoine en tuffeau, quatre critères sont apparus indispensables : les besoins de chauffage, le confort hygrothermique intérieur, le risque de dégradation du matériau et l’investissement financier. Dans ce contexte, l’objectif est de développer une démarche d’aide à la décision multicritère de stratégie de réhabilitation pérenne des bâtiments en tuffeau. Cette démarche a vocation à s’adapter à tous types de bâtiments en tuffeau et à considérer l’ensemble de ses spécificités. Un panel d’actions de réhabilitation portant sur les éléments d’enveloppe est identifié et testé sur le bâtiment considéré. La mise en place du processus a nécessité l’utilisation d’un outil de modélisation traduisant la réalité du comportement énergétique de ces bâtiments. L’outil EnergyPlus avec l’algorithme de transfert de masse et de chaleur HaMT a été mis en place et vérifié avec des mesures expérimentales. L’ensemble des résultats des stratégies de réhabilitation sont alors agrégées dans une méthode d’analyse multicritère. L'incertitude de l'évaluation des stratégies de réhabilitation est intégrée à la méthode (ELECTRE III) pour que les recommandations soient réalisées avec un degré de confiance satisfaisant. L’application de cette démarche à deux cas de bâtiments en tuffeau a mis en évidence l’adaptabilité de la démarche à des bâtiments de typologie et de complexité variables. Elle permet par ailleurs de fournir des recommandations robustes sur les travaux les plus pertinents à mener / The old buildings stock represents a true potential for energy savings. However, its diversity and some characteristics of its envelop materials interfere with the setting of effective retrofitting strategies. Among this heritage, individual limestone dwellings present specific issues concerning retrofitting. Tuffeau, particularly, is a high porosity limestone which specificity is propensity to fill up with water. Its hygrothermal properties are then affected and it quickly deteriorates.Furthermore, this kind of building offers comfortable indoor summer temperatures and undeniable architectural qualities. Those factors have to be considered during the energetic retrofitting of those dwellings. Consequently, the solutions proposed have sometimes to meet divergent goals. Concerning limestone heritage, four criteria appeared as indispensable: the heating needs, the indoor hygrothermal comfort, the material deterioration risk, and the financial investment. In thiscontext, the goal is to develop a multicriteria decision aiding method of old limestone buildings retrofitting strategies. This method has a potential to adapt to every type of limestone buildings and to consider those specificities as a whole. A panel of retrofitting actions concerning the envelop elements is identified and then tested on the concerned building. The process implementation required the use of a modeling tool to translate the reality of those buildings behaviour. The tool EnergyPlus with its mass and heat transfer algorithm HaMT was implemented and validated with experimental measures. The uncertainty of the retrofitting strategies results are thenintegrated to the method (ELECTRE III) so that the recommendation can be performed with an acceptable level of confidence.The application of this process to two cases of limestone buildings emphasized the adaptability of this method to very different buildings in term of typology and complexity. It also allows providing with robust recommendations on which retrofitting work has to be performed.

The manufacturing industry must align business values with sustainability to preserve a healthy socio-ecological environment, that ensures access for future generations to necessary resources. To better understand the interactions between business strategies and facility operations, this research aims to adopt a more holistic perspective of sustainable facility planning processes, applying the Framework for Strategic Sustainable Development. By using relevant environmental and social principles, methods, knowledge, and industrial practices, a strategic decision support was developed as a foundation for the manufacturing industry to improve their sustainable performance. This research (1) collected and analysed existing concepts and processes for sustainability in the industry; (2) developed a practical decision support tool; (3) reviewed the design by experts in the field; and (4) redesigned the tool by implementing expert recommendations. Based on the findings, it is crucial for decision makers to embed a strategic and holistic approach when considering facility design options. Therefore, the strategic decision support tool (CRAFTS) enables opportunities for a broader scope of possible improvements within the confines of the manufacturing facility by guiding experts in the field to decide between retrofitting and new construction. CRAFTS supports the industry to refine and align their business strategies and facility operations with sustainability.

Reinforced concrete frame buildings designed and built prior to the enactment of modern seismic codes of the pre-1970’s era are considered seismically vulnerable, particularly when they are subjected to strong ground motions. It is the objective of this research to develop a new and innovative seismic retrofit technology for seismic upgrading of nonductile or limited ductility reinforced concrete frame buildings involving the implementation of buckling restrained braces. To achieve this objective, combined experimental and analytical research was conducted. The experimental research involved tests of large-scales reinforced concrete frames under slowly applied lateral deformation reversals, and the analytical research involved design and nonlinear analysis of laboratory specimens, as well as design and dynamic inelastic response history analysis of selected prototype buildings in eastern and western Canada. The research project started with a comprehensive review of the building code development in Canada to assess the progression of seismic design requirements over the years, and to select a representative period within which a significant number of engineered buildings were designed and constructed with seismic deficiencies. A similar review of seismic design and detailing provisions of the Canadian Standard Association (CSA) Standard A23.3 on Design of Concrete Structures was also conducted for the same purpose. Six-storey and ten-storey prototype buildings were designed for Ottawa and Vancouver, using the seismic provisions of the 1965 National Building Code of Canada, representative of buildings in eastern and western Canadian. Preliminary static and dynamic linear elastic analyses were performed to assess the effectiveness of upgrading the ten-storey reinforced concrete building designed for Ottawa. The retrofit methods studied consisted of lateral bracing by adding reinforced concrete shear walls, diagonal steel braces, or diagonal steel cable strands. The results indicated that the retrofit techniques are effective in limiting deformations in non-ductile frame elements to the elastic range. The numerical analyses were used to demonstrate the effectiveness of Buckling Restrained Braces (BRBs) as a retrofit method for seismically deficient reinforced concrete frame buildings. The experimental phase of research consisted of two, 2/3rd scale, single bay and single storey reinforced concrete frames, designed and constructed based on a prototype sixstorey moment resisting frame building located in Ottawa and Vancouver, following the requirements of the 1965 edition of the NBCC. One test specimen served as a bare control frame (BCF) that was first tested, repaired and retrofitted (RRF) to evaluate the effectiveness of the proposed retrofit methodology for buildings subjected to earthquakes in the City of Ottawa. The control frame was assessed to be seismically deficient. The second frame served as a companion non-damaged frame (RF) that was retrofitted with a similar retrofit concept but for buildings subjected to earthquakes in the City of Vancouver. A new buckling restrained brace (BRB) was conceived and developed to retrofit existing sub-standard reinforced concrete frames against seismic actions. The new BRB consists of a ductile inner steel core and an outer circular sleeve that encompasses two circular steel sections of different diameters to provide lateral restraint against buckling in compression of inner steel core. Mortar is placed between the two circular sections to provide additional buckling resistance. The inner core is connected to novel end units that allow extension and contraction during tension-compression cycles under seismic loading while providing lateral restraint against buckling within the end zones. The end units constitute an original contribution to the design of Buckling Restrained Braces (BRBs), providing continuous lateral restraint along the core bar. The new technique has been verified experimentally by testing four BRBs on the two test structures under simulated seismic loading. The test results of the BRB retrofitted frames indicate promising seismic performance, with substantial increases in the lateral load and displacement ductility capacities by factors of up to 3.9 and 2.6, respectively. In addition, the test results demonstrate that the BRB technology can provide excellent drift control, increased stiffness, and significant energy dissipation, while the reinforced concrete frames continue fulfilling their function as gravity load carrying frames. The above development was further verified by an exhaustive analytical study using SAP2000. At the onset, analyses were conducted to calibrate and verify the analytical models. Two-dimensional, one-bay, one-storey models, simulating the BCF and RRF test frames, were created. The models were subjected to incrementally increasing lateral displacement reversals in nonlinear static pushover analyses, and the results were compared with those obtained in the test program. Material nonlinearity was modeled using “Links” to incorporate all lumped linear and nonlinear properties that were defined with moment-rotation properties for flexural frame members and with force-displacement properties for the diagonal buckling restrained braces. Comparison with test data demonstrated good agreement of the frame behaviour in the elastic and post-elastic ranges, and the loading and unloading stiffness. The research program was further augmented with nonlinear dynamic time history analyses to verify the feasibility of the new retrofit technique in multi-storey reinforced concrete frame buildings located in Canada and their performances relative to the performance-based design objectives stated in current codes. Prior to conducting the analyses, 450 artificial earthquake records were studied to select the best matches to the Uniform Hazard Spectra (UHS) according to the 2010 edition of the NBCC for Ottawa and Vancouver. Furthermore, additional analyses were conducted on buildings for the City of Ottawa based on amplified Uniform Hazard Spectrum compatible earthquake records. The nonlinear time-history response analyses were conducted using a model that permits inelasticity in both the frame elements and the BRBs.The results indicated that reinforced concrete buildings built before the 1970’s in the City of Ottawa do not require seismic retrofitting; they remain within the elastic range under current code-compatible earthquake records. The structural building performance is within the Immediate Occupancy level, and all structural elements have capacities greater than the force demands. In the City of Vancouver, buildings in their virgin state experienced maximum interstorey drifts of 2.3%, which is within the Collapse Prevention structural performance level. Improved building performance was realized by retrofitting the exterior frames with multiple uses of the BRB developed in this research project. The seismic shear demands were reduced in the columns, while limiting the deformations in the non-ductile frame elements to the elastic range. The lateral interstorey drift was limited to 0.92%, which lies within the Life Safety structural performance level.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22704号 / 工博第4751号 / 新制||工||1743(附属図書館) / 京都大学大学院工学研究科建築学専攻 / (主査)教授 池田 芳樹, 教授 西山 峰広, 准教授 聲高 裕治 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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