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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

L'appareil de l'architecture moderne : new materials and architectural modernity in France, 1889-1934

Legault, Réjean January 1997 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Architecture and Planning, 1997. / Includes bibliographical references (v. 3, leaves 470-517). / This dissertation is an historical inquiry into the role played by new building materials in the formation of architectural modernism in France. It proceeds on the theoretical assumption that a "material" is not a technical given -- a securely defined entity in the physical and linguistic senses -- but an architectural construct whose "inherent properties" are a matter of interpretation. It suggests that within a specific architectural culture, the conceptions and uses of a material are defined by concerns that are not only constructional but involve architectural doctrines, building practices, aesthetic projects, and cultural strategies. Since the publication of Sigfried Giedion's Bauen in Frankreich. Bauen in Eisen. Bauen in Eisenbeton (1928), reinforced concrete has been commonly accepted as the common denominator of French modernism. The dissertation questions this interpretive assumption, focusing on the changing conceptions of the material as an index of transformations in French architecture and architectural culture. It covers a period that spans from the Universal Exhibition of 1889 to the early 1930s, a period which saw the development of reinforced concrete in French architecture, from its emergence within architectural discourses to its inscription within early modernist historiography. Through a close examination of contemporary books and periodicals, unpublished sources, and graphic documents, the dissertation explores the theories and works that framed the critical relationship of new material to French modernism. Inaugurated with the late nineteenth-century demise of metal as the leading material in architectural theory, the preeminence of reinforced concrete in French architecture was marked by the dispersion of rationalist tenets into competing architectural programs. The First World War was a pivotal event in this process. Of principal importance were the positions of Auguste Perret and Le Corbusier. While Perret insisted on continuity with prewar practices, emphasizing the role of craft production, Le Corbusier embraced the rupture brought about by the societe machinique, shifting towards the idea of industrialized construction. These positions were key to the technical and aesthetic definition of the modem house, from the function of the concrete frame to the nature of external revetments. They also led the way to the cultural and ideological debates that ensued on the nationality of the material and the sources of modem architecture. In the late 1920s the return of metal merely underscored the "rhetoric of materials" in the definition of French modernism. / by Réjean Legault. / Ph.D.
142

Diffusion and protection mechanisms of migratory corrosion inhibitors in reinforced concrete

Phanasgaonkar, Alka, 1956- January 2000 (has links)
Abstract not available
143

Strength and ductility of fibre reinforced high strength concrete columns

Zaina, Mazen Said, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2005 (has links)
The main structural objectives in column design are strength and ductility. For higher strength concretes these design objectives are offset by generally poor concrete ductility and early spalling of the concrete cover. When fibres are added to the concrete the post peak characteristics are enhanced, both in tension and in compression. Most of the available experimental data, on fibre reinforced concrete and fibre reinforced high strength concrete columns, suggest that an improvement in both ductility and load carrying capacity due to the inclusion of the fibres. In this thesis the ductility and strength of fibre reinforced high strength concrete are investigated to evaluate the effect of the different parameters on the performance of columns. The investigation includes both experimental and the numerical approaches with 56 high strength fibre reinforced concrete columns being tested. The concrete strength ranged between 80 and 100 MPa and the columns were reinforced with 1, 2 or 2.6 percent, by weight, of end hooked steel fibres. The effect of corrugated Polypropylene fibres on the column performance was also examined. No early spalling of the cover was observed in any of the steel fibre reinforced column tested in this study. A numerical model was developed for analysis of fibre and non-fibre reinforced eccentrically loaded columns. The column is modelled as finite layers of reinforced concrete. Two types of layers are used, one to represent the hinged zone and the second the unloading portion of the column. As the concrete in the hinged layers goes beyond the peak for the stress verus strain in the concrete the section will continue to deform leading to a localised region within a column. The numerical model is compared with the test data and generally shows good correlation. Using the developed model, the parameters that affect ductility in fibre-reinforced high strength concrete columns are investigated and evaluated. A design model relating column ductility with confining pressure is proposed that includes the effects of the longitudinal reinforcement ratio, the loading eccentricity and the fibre properties and content and design recommendations are given.
144

Seismic performance of flexible concrete structures /

Feghali, Habib Labib, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 256-262). Available also in a digital version from Dissertation Abstracts.
145

Strengthening reinforced concrete bridges using carbon fiber reinforced polymer composites /

Breña, Sergio F. January 2000 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 429-435). Available also in a digital version from Dissertation Abstracts.
146

Theoretical study of hybrid masonry : RC structure behaviour under lateral earthquake loading

Ouyang, Yi, 欧阳禕 January 2012 (has links)
A confined masonry (CM) wall consists of a masonry wall panel surrounded by reinforced concrete (RC) members on its perimeters. Low-rise CM structures are widely used in earthquake-risked (EQ-risked) rural or suburban areas all over the world. Most of these structures fail in shear pattern under lateral EQ loads, and some of them collapse under a severe or even a moderate EQ due to inappropriate design. On the other hand, buildings constructed of RC frames have much better performance in resisting EQs, since their RC members have larger dimensions and heavier reinforcing ratios than those in CM structures. Nonetheless, RC-frame buildings are normally too expensive for most inhabitants in less developed regions. In this study, as an improvement to the conventional CM buildings for EQ resistance and for the sake of post-EQ restoration, a hybrid masonry – RC (HMR) structure, whose working mechanism is different from that of a conventional CM structure, is proposed. The RC members (i.e. “tie beams” and “tie columns”), which function only as confinement in a CM building, will resist most of gravity load and part of lateral EQ load in an HMR structure, while the wall panels will take most of lateral EQ load and part of gravity load. This is achievable by slightly increasing the sizes and reinforcing ratios of RC members in HMR structures. Such buildings will not collapse in the absence of masonry wall panels because the gravity load bearing system is still intact. On the other hand, as the wall panels in the proposed HMR structure will absorb most of the energy induced by lateral EQ load, severe damages will be controlled within the wall panel region, so that only the wall panels need to be replaced instead of rebuilding the whole structure after the EQ event. To investigate the mechanical behaviours of masonry assemblages to be used in HMR structures, a series of experimental tests were conducted. Having established the relevant material properties for HMR structures, finite element (FE) simulation was performed to verify its work mechanism. Prior to applying the FE simulation to HMR structures, the FE technique was first applied to simulate the behaviours of two concrete-brick masonry panels under diagonal compression loading and a CM wall under cyclic lateral loading. The results show a good correlation between the experimental results and the simulated ones. This has validated the feasibility of using the FE software to study the proposed HMR structure. The theoretical simulation results show that in a properly designed HMR wall, depending on the masonry reinforcing details and the boundary conditions of simulated load cases, about 70% of the gravity load imposed on the RC beam will be transferred to the RC columns and more than 80% of the seismic energy (in terms of strain energy) will be absorbed by the masonry panel. Therefore, it is obvious that the proposed HMR structure is very feasible to replace the conventional CM structure in resisting EQ attacks with no risk of collapse. / published_or_final_version / Civil Engineering / Master / Master of Philosophy
147

Composite structural members for short span highway bridges

Ulloa Barbaran, Fernando Valentin 28 August 2008 (has links)
Not available / text
148

Development of a CFRP system to provide continuity in existing reinforced concrete buildings vulnerable to progressive collapse

Orton, Sarah Lynn, 1978- 28 August 2008 (has links)
Reinforced concrete buildings may be vulnerable to progressive collapse due to a lack of continuous reinforcement. Progressive collapse is an extreme form of collapse that is disproportionate to the originating cause. Such collapses cause not only significant damage to buildings, but also greater loss of life and injuries. Carbon fiber reinforced polymer (CFRP) may be used to retrofit existing reinforced concrete beams and provide the missing continuity needed to resist progressive collapse. This research focuses on retrofitting the beams in a reinforced concrete building to provide sufficient continuity to reach catenary action. The catenary action may allow the beam to carry vertical loads at large displacements if a supporting column were removed. The CFRP can provide continuity through the negative moment reinforcement or through the positive moment reinforcement. The research was broken into three major components. Anchorage tests form the design basis of the CFRP retrofit and ensure that the capacity of the retrofit can be accurately predicted. Continuity tests determine if the CFRP retrofit is capable of providing continuity and if the retrofit will allow the beam to reach catenary action and sustain a load representing resistance to progressive collapse. The analysis model forms a set of equations for catenary action so the results can be applied to reinforced concrete beams in general. Forty anchorage tests, eight continuity tests, and one analysis model were constructed and evaluated. The anchorage tests found that carbon fiber anchors enabled improved utilization of the tensile capacity of a CFRP sheet and improved the efficiency of material usage in CFRP retrofits. The continuity tests found that beams without continuous reinforcement can reach catenary action (depending on design details) and a CFRP retrofit, if designed correctly (placed in locations that do not cause rebar fracture before catenary), may be able to reduce vulnerability to progressive collapse. The analysis model was able to accurately predict the load-deflection behavior of a reinforced concrete beam in catenary action. The overall conclusion is that a CFRP retrofit can reduce vulnerability to progressive collapse in reinforced concrete buildings. / text
149

Progressive collapse behavior of reinforced concrete structures with deficient details

Kim, Hyunjin, 1974 Jan. 21- 10 August 2011 (has links)
Not available / text
150

Kareivinių pastatas šiaulių rajone Mumaičių kaime / Barrack building šiauliai area mumaičiai village

Šėgžda, Aidas 01 August 2013 (has links)
Šiame bakalauro baigiamajame darbe suprojektuotas trijų aukštų kareivinių pastatas su sporto sale ir rūsiu. Pastatą numatyta statyti Šiaulių rajone Mumaičių kaime esančioje karinio dalinio teritorijoje. Pirmajame, antrajame ir trečiajame aukšte išdėstomos patalpos skirtos vienai kuopai. Rūsyje įrengiamos patalpos ginklų saugykloms, ginklų valymui ir kuopų daiktų saugyklos. Prieš pastatą įrengiama rikiuotės aikštė, šaligatviai pėstiesiems, numatyta galimybė privažiuoti prie pastato transportui, likusi sklypo dalis apželdinama.Projektą sudaro architektūrinė, konstrukcinė, technologinė-ekonominė dalys, bei brėžiniai.Pirmojoje – architektūrinėje – dalyje aprašomas sklypas, pastato charakteristika, jo inžineriniai tinklai, bei konstrukciniai ir apdailos sprendimai. Brėžiniuose pateikiami sklypo ir pastato planai, fasadai, pjūvis bei mazgai. Konstrukcinėje dalyje projektuojama plieninė sija S1 ir gelžbetoninė stendinio formavimo perdangos plokštė PK-53-14-S600. Pridedami šių konstrukcijų darbo brėžiniai. Technologinėje-ekonominėje dalyje pateikiami kai kurių darbų technologijos, technologinė kortelė, darbų kiekių žiniaraštis bei pagal tuos kiekius parengta lokalinė sąmata, kiti žiniaraščiai. Grafinėje dalyje pateikiamas statybvietės planas, kuriame numatytas eismas statybų teritorijoje, medžiagų aikštelės, darbuotojų buitinės patalpos, parinktas kranas. / This Bachelor’s work of designing three-story barracks building with a gym and a basement. The building is planned to construct Siauliai district Mumaičiai village in the territory of the military unit. The first, second and third floor space arranged for one company. Installed in the basement room weapon storage, gun cleaning and companies storage. Before building equipped formation Square, sidewalks for pedestrians, the possibility of approaching the building of transport, the remaining part of the plot plante. The project consists of architectural, structural, technological-economic parts and drawings. The first - the architecture - describes the plot, building characteristics, the engineering systems, and the construction and finishing solutions. The drawings presented in the site and building plans, elevations, sections and assemblies.The constructive part of the design of steel beam S1 and reinforced concrete floor slab forming poster PK-53-14-S600. These structures are attached drawings.Technological-economic section describes some of the work, technological card, work records and quantities of quantities prepared by local estimate, the other sheets. The graphic layout of the building, which includes traffic building sites, material sites, employee household premises, selected The project is carried out in accordance with the Ministry of construction law, building regulations (STR), the rules and background material provided in the reference list.

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