Dissertations / Theses on the topic 'Concrete walls Design and construction'
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Riley, Benjamin. "Concrete living walls." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE2027/document.
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Bâtir de villes face à la surpopulation tout en prenant en compte les changements climatiques, demandera de faire appel à des solutions concrètes pour répondre aux besoins sanitaires, sécuritaires et biophiliques de leurs habitants. Le but de cette thèse est d'évaluer la possibilité d'avoir un système de mur vivant qui soit durable, écologiquement juste, non limité par la localisation et la typologie du bâtiment et plus abordable que les systèmes actuellement disponibles. L'hypothèse de cette thèse est le béton, en raison de sa durabilité, son coût et son ubiquité, a le potential pour être utilisé comme un moyen de croissance pour la vie végétale et qu'il s'agit actuellement du matériau le plus réaliste pour étendre la portée de la nature dans le milieu urbain.La thèse est pluridisciplinaire et il faudra combiner les connaissances des sciences de la botanique et des matériaux, connaissances qui seront appréhendées au travers d'un prisme architectural. Ce point de vue influencera la trajectoire de la conception future du système, par exemple pour déterminer si le système pourrait être structurel et utilisé pour l'intérieur et l'extérieur des bâtiments bas, moyens et hauts, ou encore quelles ambiance architecturales et urbaines il est susceptible de créer. Cette thèse de doctorat déterminera la faisabilité des systèmes de murs vivants en béton et, si elle est validée, fournira la base pour des solutions durables de murs vivants en bétonCities facing overpopulation amid shifting climates will require practicable solutions to meet the biophilic, health, and safety needs of city dwellers. The goal of this thesis is to determine the possibility of having a living wall system which is durable, environmentally sustainable, unlimited by location and building typology, and more affordable than currently available systems. The hypothesis of this thesis is that concrete,due to its durability, cost, and ubiquity, is capable of being used as a growing medium for plant life and is currently the most realistic material choice to significantly extend nature’s reach into the urban milieu. The thesis is multi-disciplinary and combines botany and material science, but architecture is the lens throughwhich the inter-disciplinary work is validated. This architectural lens will influence the trajectory of future system design, e.g., in determining if the system would have the potential of being structural and used for the interiors and exteriors of low, mid, and high-rise buildings. This doctoral thesis would determine the feasibility of concrete living wall systems and if validated provide the foundation for sustainable concrete living wall solutions
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Lim, Chim Chai. "Analysis, design, and construction of tilt-up wall panel." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45801.
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The idea of tilt-up construction started in America in the early I900’s. In the beginning, this technique was mainly used on structures such as industrial warehouses and factories. However, recent developments and improvements in tilt-up construction technique and accessories have enabled this building method to be applied to many architecturally appealing offices and residential structures.
There are many details the design-build team must consider to ensure the success of a tilt-up project. The floor slab must be designed for panel casting and to withstand the loading of the mobile crane which will be used to lift the panel. The crane capacity affects the panel size and weight. Proper curing and bondbreaker application are very important to reduce bonding and to ensure clear cleavage between concrete surfaces. Changing rigging configuration consumes expensive crane time and must be reduced to minimum possible. The availability of ground-release quick connect/disconnect tilt—up hardware improves workers safety and speeds up the erection process substantially.
Although the stress analysis of simple wall panels during erection can be done by hand, panels with more complicated geometry or with openings, are more efficiently analysed with a computer. Many manufacturers have technical services to help in the design of insert layout so that the concrete will not be over stressed when the panel is tilted into position. After the panel is plumbed, it is braced temporarily before the final connection is made. For in-place loading there are now design aids available which ease the design process. When properly designed and built, tilt—up has proved to be a fast, efficient, and economical building construction technique.Master of Science
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Khalil, Ahmed Amir Ghobarah Ahmed. "Rehabilitation of reinforced concrete structural walls using fibre composites /." *McMaster only, 2005.
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Garth, John Stuart. "Experimental Investigation of Lateral Cyclic Behavior of Wood-Based Screen-Grid Insulated Concrete Form Walls." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1857.
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Insulated concrete forms (ICFs) are green building components that are primarily used for residential wall construction. Unlike most polystyrene based ICF variants, the Faswall ICFs used in these experiments were significantly denser because they were made from recycled wood particles and cement. The current design approach for structures constructed with this type of wall form only allows the designer to consider the contribution of the reinforced concrete cores. Previous research has shown that this approach may be conservative. This project experimentally evaluated the lateral structural response of these types of grid ICF walls under increasing amplitude of in-plane cyclic loading. Two different height-to-length (aspect) ratios (approximately 2:1 and 1:1) were investigated, as was the effect of simultaneous gravity load. Furthermore, the reinforced concrete grid was exposed for each aspect ratio in order to examine the contribution of the ICF blocks to the lateral response. Analyses of hysteretic behaviors and failure modes indicated conservatism in the current design approach for estimating lateral strength and ignoring the beneficial contribution of the ICF blocks to overall performance. The presence of the wall forms increased the lateral shear capacity of the walls by an average of 42% (compared to the walls with forms removed), while also increasing the deformation capacity by an average of 102%. Furthermore, by considering an additional gravity load of 10 kips-per-lineal-foot (klf), the shear resistance of the walls increased by 32% (versus walls only subjected to self-weight), on average, and the deformation capacity of the walls increased by an average of 19%. Comparisons of the experimental results to several design equations led to the recommendation of a design equation that was previously accepted for another type of ICF system.
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Spathelf, Christian Alexander. "Assessment of the behaviour factor for the seismic design of reinforced concrete structural walls according to SANS 10160 : part 4." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/2039.
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McLeod, Christina Helen. "Investigation into cracking in reinforced concrete water-retaining structures." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80207.
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Thesis (MScEng)--Stellenbosch University, 2013.Durability and impermeability in a water-retaining structure are of prime importance if the structure is to fulfill its function over its design life. In addition, serviceability cracking tends to govern the design of water retaining structures. This research concentrates on load-induced cracking specifically that due to pure bending and to direct tension in South African reinforced concrete water retaining structures (WRS). As a South African design code for WRS does not exist at present, South African designers tend to use the British codes in the design of reinforced concrete water-retaining structures. However, with the release of the Eurocodes, the British codes have been withdrawn, creating the need for a South African code of practice for water-retaining structures. In updating the South African structural design codes, there is a move towards adopting the Eurocodes so that the South African design codes are compatible with their Eurocode counterparts. The Eurocode crack model to EN1992 (2004) was examined and compared to the corresponding British standard, BS8007 (1989). A reliability study was undertaken as the performance of the EN1992 crack model applied to South African conditions is not known. The issues of the influence of the crack width limit and model uncertainty were identified as being of importance in the reliability crack model.
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Le, Roux Rudolf Cornelis. "Assessment of seismic drift of structural walls designed according to SANS 10160 - Part 4." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5282.
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Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Reinforced concrete structures, designed according to proper capacity design guidelines, can deform inelastically without loss of strength. Therefore, such structures need not be designed for full elastic seismic demand, but could be designed for a reduced demand. In codified design procedures this reduced demand is obtained by dividing the full elastic seismic demand by a code-defined behaviour factor. There is however not any consensus in the international community regarding the appropriate value to be assigned to the behaviour factor. This is evident in the wide range of behaviour factor values specified by international design codes. The purpose of this study is to assess the seismic drift of reinforced concrete structural walls in order to evaluate the current value of the behaviour factor prescribed by SANS 10160-4 (2009). This is done by comparing displacement demand to displacement capacity for a series of structural walls. Displacement demand is calculated according to equivalency principles (equal displacement principle and equal energy principle) and verified by means of a series of inelastic time history analyses (ITHA). In the application of the equivalency rules the fundamental periods of the structural walls were based on cracked sectional stiffness from moment-curvature analyses. Displacement capacity is defined by seismic design codes in terms of inter storey drift limits, with the purpose of preventing non-structural damage in building structures. In this study both the displacement demand and displacement capacity were converted to ductility to enable comparison. The first step in seismic force-based design is the estimation of the fundamental period of the structure. The influence of this first crucial step is investigated in this study by considering two period estimation methods. Firstly, the fundamental period may be calculated from an equation provided by the design code which depends on the height of the building. This equation is known to overestimate acceleration demand, and underestimate displacement demand. The second period estimation method involves an iterative procedure where the stiffness of the structure is based on the cracked sectional stiffness obtained from moment-curvature analysis. This method provides a more realistic estimate of the fundamental period of structures, but due to its iterative nature it is not often applied in design practice. It was found that, regardless of the design method, the current behaviour factor value prescribed in SANS 10160-4 (2010) is adequate to ensure that inter storey drift of structural walls would not exceed code-defined drift limits. Negligible difference between the equivalency principles and ITHA was observed.
AFRIKAANSE OPSOMMING: Gewapende beton strukture wat ontwerp is volgens goeie kapasiteitsontwerp-riglyne kan plasties vervorm sonder verlies aan sterkte. Gevolglik hoef hierdie strukture nie vir die volle elastiese seismiese aanvraag ontwerp te word nie, maar kan vir 'n verminderde aanvraag ontwerp word. In gekodifiseerde ontwerpriglyne word so 'n verminderde aanvraag verkry deur die volle elastiese aanvraag te deel deur 'n kode-gedefinieerde gedragsfaktor. Wat egter duidelik blyk uit die wye reeks van gedragsfaktor waardes in internasionale ontwerp kodes, is dat daar geen konsensus bestaan in die internasionale gemeenskap met betrekking tot die geskikte waarde van die gedragsfaktor nie. Die doel van hierdie studie is om seismiese verplasing van gewapende beton skuifmure te evalueer ten einde die waarde van die gedragsfaktor wat tans deur SANS 10160-4 (2009) voorgeskryf word te assesseer. Dit word gedoen deur verplasingsaanvraag te vergelyk met verplasingskapasiteit. In hierdie studie word verplasingsaanvraag bereken deur middel van gelykheidsbeginsels (gelyke verplasingsbeginsel en gelyke energiebeginsel) en bevestig deur middel van nie-elastiese tydsgeskiedenis analises (NTGA). Die effek van versagting as gevolg van nie-elastiese gedrag word in aanmerking geneem in die toepassing van die gelykheidsbeginsels. Verplasingskapasiteit word deur seismiese ontwerpkodes gedefinieer deur perke te stel op die relatiewe laterale beweging tussen verdiepings, met die doel om nie-strukturele skade te verhoed. Om verplasingsaanvraag en -kapasiteit te vergelyk in hierdie studie, word beide omgeskakel na verplasingsduktiliteit. Die eerste stap in kraggebaseerde seismiese ontwerp is om die fundamentele periode te beraam. Die invloed van hierdie eerste kritiese stap word in hierdie studie aangespreek deur twee periodeberamingsmetodes te ondersoek. Eerstens kan die fundamentele periode bereken word deur 'n vergelyking wat 'n funksie is van die hoogte van die gebou. Dit is egter algemeen bekend dat hierdie vergelyking versnellingsaanvraag oorskat en verplasingsaanvraag onderskat. Die tweede metode behels 'n iteratiewe prosedure waar die styfheid van die struktuur gebaseer word op die gekraakte snit eienskappe, verkry vanaf 'n moment-krommingsanalise. 'n Beter beraming van die fundamentele periode word verkry deur hierdie metode, maar as gevolg van die iteratiewe aard van die metode word dit selde toegepas in ontwerppraktyk. Die resultate van hierdie studie toon dat die huidige waarde van die gedragfaktor soos voorgeskryf in SANS 10160-4 (2010) geskik is om te verseker dat die relatiewe laterale beweging tussen verdiepings binne kode-gedefinieerde perke sal bly. Onbeduidende verskil is waargeneem tussen die resultate van gelykheidsbeginsels en NTGA.
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Van, der Merwe Johann Eduard. "Rocking shear wall foundations in regions of moderate seismicity." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1957.
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Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: In regions of moderate seismicity it has been shown that a suitable structural system is created when designing the shear wall with a plastic hinge zone at the lower part of the wall, with the shear walls resisting lateral loads and all other structural elements designed to resist gravity loads. A suitably stiff foundation is required for the assumption of plastic hinge zones to hold true. This foundation should have limited rotation and should remain elastic when lateral loads are applied to the structure. Ensuring a foundation with a greater capacity than the shear wall results in excessively large shear wall foundations being required in areas of moderate seismicity for buildings with no basement level. This study aims to investigate the feasibility of reducing the size of shear wall foundations in areas of moderate seismicity for buildings with no basement level. The investigation is aimed at allowing shear wall foundation rocking and taking into account the contribution of structural frames to the lateral stiffness of the structure. An example building was chosen to investigate this possibility. Firstly, lateral force-displacement capacities were determined for a shear wall and an internal reinforced concrete frame of this investigated building. Nonlinear momentrotation behaviour was determined for the wall foundation size that would traditionally be required as well as for six other smaller foundations. The above capacity curves against lateral loads were then used to compile a simplified model of the structural systems assumed to contribute to the lateral stiffness of the building. This simplified model therefore combined the effect of the shear wall, internal frame and wall foundation. Nonlinear time-history analyses were performed on this simplified model to investigate the dynamic response of the structure with different wall foundation sizes. By assessing response results on a global and local scale, it was observed that significantly smaller shear wall foundations are possible when allowing foundation rocking and taking into account the contribution of other structural elements to the lateral stiffness of the building.
AFRIKAANSE OPSOMMING: Daar is reeds getoon dat ʼn voldoende strukturele sisteem verkry word in gebiede van gematigde seismiese risiko indien ʼn skuifmuur ontwerp word met ʼn plastiese skarnier sone naby die ondersteuning van die muur. Skuifmure word dan ontwerp om weerstand te bied teen laterale kragte met alle ander strukturele elemente ontwerp om gravitasie kragte te weerstaan. Vir die aanname van plastiese skarnier sones om geldig te wees word ʼn fondasie met voldoende styfheid benodig. Só ʼn fondasie moet beperkte rotasie toelaat en moet elasties bly wanneer laterale kragte aan die struktuur aangewend word. ʼn Fondasie met ʼn groter kapasiteit as dié van die skuifmuur lei daartoe dat uitermate groot fondasies benodig word in gebiede van gematigde seismiese risiko vir geboue met geen kelder vlak. Hierdie studie is daarop gemik om die moontlikheid van kleiner skuifmuur fondasies te ondersoek vir geboue met geen kelder vlak in gebiede van gematigde seismiese risiko. Die ondersoek het ten doel om skuifmuur fondasie wieg aksie toe te laat en die bydrae van strukturele rame tot die laterale styfheid van die struktuur in ag te neem. Eerstens is die laterale krag-verplasing kapasiteit van ʼn skuifmuur en ʼn interne gewapende beton raam van die gekose gebou bepaal. Nie-lineêre moment-rotasie gedrag is bepaal vir die skuifmuur fondasie grootte wat tradisioneel benodig sou word asook vir ses ander kleiner fondasie grotes. Die bogenoemde kapasiteit kurwes is gebruik om ʼn vereenvoudigde model van die strukturele sisteme wat aanvaar word om laterale styfheid tot die gebou te verleen, op te stel. Hierdie vereenvoudigde model kombineer gevolglik die effek van die skuifmuur, interne raam en skuifmuur fondasie. Nie-lineêre tydgeskiedenis analises is uitgevoer op die vereenvoudigde model ten einde die dinamiese reaksie van die struktuur te ondersoek vir verskillende fondasie grotes. Resultate is beoordeel op ʼn globale en lokale vlak. Daar is waargeneem dat aansienlik kleiner skuifmuur fondasies moontlik is deur wieg aksie van die fondasie toe te laat en die bydrae van ander strukturele elemente tot die laterale styfheid van die gebou in ag te neem.
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Yuksel, Bahadir S. "Experimental Investigation Of The Seismic Behavior Of Panel Buildings." Phd thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/2/1070309/index.pdf.
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Shear-wall dominant multi-story reinforced concrete structures, constructed by using a special tunnel form technique are commonly built in countries facing a substantial seismic risk, such as Chile, Japan, Italy and Turkey. In 1999, two severe urban earthquakes struck Kocaeli and Düzce provinces in Turkey with magnitudes (Mw) 7.4 and 7.1, respectively. These catastrophes caused substantial structural damage, casualties and loss of lives. In the aftermath of these destructive earthquakes, neither demolished nor damaged shear-wall dominant buildings constructed by tunnel form techniques were reported. In spite of their high resistance to earthquake excitations, current seismic code provisions including the Uniform Building Code and the Turkish Seismic Code present limited information for their design criteria. This study presents experimental investigation of the panel unit having H-geometry. To investigate the seismic behavior of panel buildings, two prototype test specimens which have H wall design were tested at the Structural Mechanics Laboratory at METU. The experimental work involves the testing of two four-story, 1/5-scale reinforced concrete panel form building test specimens under lateral reversed loading, simulating the seismic forces and free vibration tests. Free vibration tests before and after cracking were done to assess the differences between the dynamic properties of uncracked and cracked test specimens. A moment-curvature program named Waller2002 for shear walls is developed to include the effects of steel strain hardening, confinement of concrete and tension strength of concrete. The moment-curvature relationships of panel form test specimens showed that walls with very low longitudinal steel ratios exhibit a brittle flexural failure with very little energy absorption. Shear walls of panel form test specimens have a reinforcement ratio of 0.0015 in the longitudinal and vertical directions. Under gradually increasing reversed lateral loading, the test specimens reached ultimate strength, as soon as the concrete cracked, followed by yielding and then rupturing of the longitudinal steel. The displacement ductility of the panel form test specimens was found to be very low. Thus, the occurrence of rupture of the longitudinal steel, as also observed in analytical studies, has been experimentally verified. Strength, stiffness, energy dissipation and story drifts of the test specimens were examined by evaluating the test results.
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Pilakoutas, Kypros. "Earthquake resistant design of reinforced concrete walls." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/7215.
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Jabbour, Samer. "Comparative design of reinforced concrete shear walls." Thesis, University of Ottawa (Canada), 2000. http://hdl.handle.net/10393/10755.
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Code provisions for the determination of earthquake loads are intended to give reasonable estimate of the lateral forces that occur on a building as a result of an earthquake. Two major steps can be described in the procedure: the calculation of the base shear based on both the characteristics of the earthquake and the building, and the distribution of the base shear over the stories and the resisting earthquake elements of the building. Reinforced concrete ductile shear walls are the earthquake resisting elements considered in this study. Code provisions for the design of reinforced concrete ductile shear walls are intended to provide adequate reinforcement details and concrete strength to permit inelastic response under major earthquakes without critical damage or collapse. The objective of this study is to provide, using an assumed building in Victoria, British Columbia, detailed description of the design procedures used by different design codes, and to compare the results obtained on the earthquake loads determination and on the reinforcement details provided to the shear walls. The NBCC-1995 and the IBC-2000 design code procedures were used to determine the earthquake design loads in Chapter 2, and the ACI318-99, the CSA-1995 and the NZS-1995 were used to design a reinforced concrete shear wall in Chapter 3. Comparative conclusions are presented Chapter 4. Generally, design of reinforced concrete shear walls using Canadian, American, and New Zealand provisions should be done based on the earthquake loads obtained from code provisions of Canada, the United States, and New Zealand, namely the comprehensive provisions of NBCC-1995/CSA23.3-94, IBC-200/ACI318-99, and NZS:3101:1995 respectively. However, it was necessary in this study to use the same loads in the different reinforced concrete shear wall design procedures in order to make comparative conclusions more effective. Therefore, the earthquake loads obtained from NBCC-1995 provisions were exclusively used to do the three different design procedures of reinforced concrete design using the code provisions of ACI318-99, CSA23.3-94, and NZS:3101:part 1:1995 respectively. The choice was based on the fact that the location of the building is in Canada. The fundamental assumptions that were made in this study include that: the building, described in Section 2.2, is be braced by reinforced concrete ductile shear wall systems, which means that the shear walls resisting system will resist 100% of the lateral forces resulting from an earthquake. The shear wall considered in the design has adequate foundation able to transmit 100% of all structural actions to the ground.
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Cheung, Kwong-chung. "Reinforced earth wall design & construction in northern access road for Cyberport Development /." View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B3676288X.
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Bostanci, Sevket Can. "Low carbon sustainable concrete design and construction." Thesis, Kingston University, 2015. http://eprints.kingston.ac.uk/34545/.
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Fitzmaurice, Silas James. "Blast retrofit design of CMU walls using polymer sheets." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4569.
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Thesis (M.S.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 17, 2009) Includes bibliographical references.
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DEASON, JEREMY THOMAS. "SEISMIC DESIGN OF CONNECTIONS BETWEEN STEEL OUTRIGGER BEAMS AND REINFORCED CONCRETE WALLS." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1021661255.
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Amjadi, Cindy, and Justyna Melek. "The impact of stage casting on shrinkage restraint in concrete walls." Thesis, KTH, Byggteknik och design, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279467.
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The most used widely material in the construction and industrial industry is concrete. Concrete is a material that has been used for a long time and will remain to do so. Therefore, it is especially important to obtain knowledge of the material’s properties and how it is affected by various conditions. A major problem with concrete is cracking that occurs when its shrinkage is prevented. When a concrete wall is cast against ground, shrinkage occurs. The cracks that develop due to this can cause leaks and reinforcement corrosion that not only reduces the lifespan of the concrete, but are also making it aesthetically ugly. One solution to reduce the restraint is to divide the casting into stages. This study contains investigation whether a thoughtful stage casting is a method that can theoretically and practically affect the shrinkage restraint and thereby the cracking in concrete walls. This report observes the tensile stresses in a 15 meter long concrete wall with strength class C30/37. The wall is exposed for two different relative humidity circumstances, indoor environment which gives 50% and outdoor environment which gives 80%. The analysis comprises four different casting methods for a wall; casting in one piece and three casting methods according to thoughtful stage casting. The contemplated time range between the casting stages is normal production time, 30 days, and extended production time, 60 days. At first the calculations for shrinkage and creep of the concrete had to be done according to Eurocode 2. The results from the calculations are thereafter used in the finite element program FEM-Design from the company Strusoft. The results in the report demonstrates the tensile stresses that arise in a 15 meter long wall without the stages and when the casting is done with thoughtful stages. A variation of the foundation depth consisting of non-cohesive soil is also presented for one of the casting methods. The conclusion of the results is that stage casting is a solution to reduce restraint and thereby stresses in concrete walls. The results reveal that the tensile stresses are reduced with the highest value of approximately 80%. The efficiency of casting into stages is possible and practicable within a normal production time.Det mest använda materialet i anläggnings- och industribranschen är betong. Betong är ett material som har använts länge och kommer fortsätta att användas. Därför är det främst viktigt att ha kunskap om materialets egenskaper och hur det påverkas av olika förhållanden. Ett stort problem med betong är sprickbildning när dess krympning förhindras. När en betongvägg gjuts mot ett underlag förekommer krymptvång. Sprickorna som uppstår på grund av detta kan orsaka läckage och armeringskorrosion som minskar betongens livslängd och är dessutom estetiskt fula. Ett sätt att minska tvånget är att dela in gjutningen i etapper. I detta arbete undersöks om en genomtänkt gjutetappsindelning är en metod som teoretiskt och praktiskt kan påverka krymptvånget och därmed sprickbildningen i betongväggar. Denna rapport betraktar dragspänningarna i en 15 meter lång betongvägg med hållfasthetsklassen C30/37. Väggen utsätts för två olika relativa luftfuktighetsförhållanden, inomhusmiljö samt utomhusmiljö vilket ger ett värde på 50% och 80%. Analyserna omfattar fyra olika gjutningsmetoder för väggen; gjutning utan etappindelning samt gjutning utförd enligt tre genomtänkta etappindelningar. Tiden som betraktas mellan gjutetappsindelningarna begränsas till normal produktionstid, 30 dagar, och en förlängd produktionstid, 60 dagar. Först utförs handberäkningar enligt Eurokod 2 på betongens krympning och krypning för att sedan sätta in resultaten i finita element programmet FEM-Design från Strusoft. Resultaten i rapporten redovisar de maximala dragspänningarna som uppstår i en 15 meter lång vägg utan etappindelning och då gjutning genomförs av genomtänkt etappindelning. Även en variation av friktionsjordens djup analyseras för en utav etappindelningarna. Slutsatsen av resultaten är att gjutetappindelning är en lösning till reduktion av tvång och därmed minskad spänning i betongväggar, då de maximala dragspänningarna reducerades med som högst ca 80%. Effektiviteten av gjutetappindelning är möjlig inom en normal utförandetid.
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Ho, Ching-ming Johnny, and 何正銘. "Inelastic design of reinforced concrete beams and limited ductilehigh-strength concrete columns." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B27500305.
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Leung, Chun-yu Cliff, and 梁鎮宇. "Performance of in-situ concrete stitches in precast concrete segmentalbridges." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49617758.
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Multi-span precast concrete segmental bridges are commonly constructed using the balanced cantilever method, which essentially involves sequentially extending precast segments outwards from each pier in a balanced manner. A gap of 100 to 200 mm wide is usually provided around the mid-span location between the last two approaching segments to facilitate erection. In-situ concrete is then cast to ‘stitch’ the segments together, thus making the bridge deck continuous. In the current practice, the in-situ concrete stitches are usually designed to be capable of sustaining considerable sagging moment but only minimal hogging moment. Failure of stitches may occur under exceptional circumstances that may potentially trigger a progressive collapse. However, relatively little research in this area has been carried out.
In view of this, the author is motivated to undertake an extensive study of the behaviour of in-situ concrete stitches and the effects of their performance on the robustness of typical segmental bridges. Experimental study is carried out to examine the behaviour of in-situ stitches under different combinations of internal forces. Series of stitch specimens of different configurations are tested. Subsequent parametric studies are conducted numerically to examine the effects of various parameters on the load-displacement characteristics of the stitches. Formulae for strength estimation are proposed based on the results.
A study of robustness involves analyzing the collapse behaviour of a structure in an extreme event and the analysis should be carried out up to and then well beyond the state of peak strength of structural members. A finite element programme for post-peak analysis is therefore developed for the present study. As the ability of a member section to sustain large inelastic deformation can ultimately affect the robustness of a structure, an investigation is conducted to examine the effects of steel content, yield strength and prestressing level on the ductility and deformability of prestressed concrete sections.
Using the programme developed, the formation of collapsing mechanisms of a multi-span segmental bridge deck in an extreme event is examined. A typical bridge deck is subject to prescribed accidental load on its span in order to analyze the sequence of failure. Substantial redistribution of internal forces along the deck is observed as failures initiate, thus causing subsequent failures of other deck sections even though they have been designed to resist the internal forces at the ultimate limit state. The results indicate that any span of a multispan bridge may become a temporary end-span in the event of collapse of an adjacent span and the strength of the sections must be designed accordingly to prevent progressive failure. As a span becomes a temporary end-span, the in-situ concrete stitches may experience substantial moment and shear, and their failure could potentially trigger progressive collapse of the entire bridge deck.
Towards the end of the thesis, important design considerations that can enhance the performance of in-situ concrete stitches and robustness of precast concrete segmental bridges are presented.published_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy
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Cheung, Kwong-chung, and 張光中. "Reinforced earth wall design & construction in northern access road for Cyberport Development." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B45014279.
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Toranzo-Dianderas, Luis Alberto. "The use of rocking walls in confined masonry structures : a performance-based approach." Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2002. http://hdl.handle.net/10092/2099.
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Excessive economic loss and large social impact, due to extensive damage and operational problems in aseismic structures, has been observed following recent earthquakes. This situation is leading to the formulation of a new design paradigm in seismic-engineering. Performance-based design, addressing life-safety, damage-control and functionality issues, is expected to supersede in the near future the current prescriptive serviceability/life-safety approach. In this context, the observed extent of damage in masonry structures, as a consequence of recent moderate and strong earthquakes, seems to disqualify this traditional material in a performance-based environment. Masonry-structures with low density of lateral-force-resisting masonry-walls are among the buildings most likely to be damaged by moderate and strong earthquakes. The use of rocking walls is proposed here as an alternative to improve the seismic performance of these kind of buildings without having to give up the masonry as an integral part of the structure. It was found that rocking confined-masonry walls with hysteretic-energy-dissipators at their base can be reliably designed to match target drifts, which are closely correlated to the extent of the damage in a building. It is shown in this thesis that hysteretic-energy-dissipators can provide a reliable energy-dissipation source that allows the seismic design of this sort of structures with any of the new methodologies proposed to meet seismic performance-objectives, A design procedure adapted from the Direct Displacement Method is developed in the core of this thesis. A prototype structure is designed with the proposed method and a reduced-scale model is built and tested dynamically in a shake table. The experimental results confirmed that rocking walls can be successfully adapted to confined masonry structures. A numerical analysis is also conducted here, with good matching of the experimental results, providing a new tool to deepen the understanding of this system.
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Chai, Hsi-Wen. "Design and testing of self-compacting concrete." Thesis, University College London (University of London), 1998. http://discovery.ucl.ac.uk/1317644/.
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Self-compacting concrete (SCC) can flow into place and compact under its own weight into a uniform void free mass even in areas of congested reinforcement. The research reported in this thesis examined the production of SCC with readily available UK materials, with the overall aims of evaluating test methods and establishing a suitable mix design procedure. There have been significant recent developments and applications of SCC in several countries, notably Japan. A literature survey gave an understanding of the advantages and properties of SCC, test methods and the range of constituent materials and their relative proportions for its successful production. A range of SCC mixes can be produced with the common features of a lower aggregate content than conventional concrete and the use of superplasticizers. Most mixes also contained one or more of pulverized fuel ash, ground granulated blast furnace slag and an inert powder filler. A four stage experimental programme was carried out: *tests on pastes to assess the effect of the types and proportions of the powders and superplasticizers on the rheology. *tests on mortars to determine suitable dosage of superplasticizers for high fluidity, low segregation and low loss of workability with time after mixing. Flow spread and funnel tests were used. *tests on fresh concrete to enable suitable types and quantities of coarse aggregate to be combined with these mortars to produce SCC. Fluidity and viscosity were measured using slump flow and V-funnel tests, and passing ability using L- and U-type tests. Two-point workability tests were also carried out, and a novel way of assessing segregation resistance was developed. *tests on hardened concrete to determine compressive strength, bond to reinforcement and drying shrinkage. A mix design procedure, based on a method suggested by Japanese workers, has been developed. This includes optimisation of the mix with a linear optimisation tool from a commercial spreadsheet package.
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Mohamed, Nayera Ahmed Abdel-Raheem. "Strength and drift capacity of GFRP-reinforced concrete shear walls." Thèse, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6136.
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With the rise in constructing using FRP reinforcement, owing to corrosion problems in steel-reinforced structures, there is a need for a system to resist lateral loads induced from wind and earthquake loads. The present study addressed the applicability of reinforced-concrete shear walls totally reinforced with glass-fiber-reinforced polymer (GFRP) bars to attain reasonable strength and drift requirements as specified in different codes. Four large-scale shear walls - one reinforced with steel bars (as reference specimen) and three totally reinforced with GFRP bars - were constructed and tested to failure under quasi-static reversed cyclic lateral loading. The GFRP-reinforced walls had different aspect ratios covering the range of medium-rise walls. The reported test results clearly showed that properly designed and detailed GFRPreinforced walls could reach their flexural capacities with no strength degradation, and that shear, sliding shear, and anchorage failures were not major problems and could be effectively controlled. The results also showed recoverable and self-centering behavior up to allowable drift limits before moderate damage occurred and achieved a maximum drift meeting the limitation of most building codes. Acceptable levels of energy dissipation accompanied by relatively small residual forces, compared to the steel-reinforced shear wall, were observed. Finite element simulation was conducted and the analyses captured the main features of behavior. Interaction of flexural and shear deformations of the tested shear walls was investigated. It was found that relying on the diagonal transducers tended to overestimate shear distortions by 30% to 50%. Correcting the results based on the use of vertical transducers was assessed and found to produce consistent results. Decoupling the flexural and shear deformations was discussed. Using GFRP bars as elastic material gave uniform distribution of shear strains along the shear region, resulting in shear deformation ranging from 15 to 20% of total deformation. The yielding of the steel bars intensified the shear strains at the yielding location, causing significant degradation in shear deformation ranging from 2 to 40% of total deformation. The results obtained demonstrated significantly high utilization levels of such shear wall type, therefore, primary guidelines for seismic design of GFRP-reinforced shear wall in moderate earthquakes regions was presented, as no design guidelines for lateral load resistance for GFRP-reinforced walls are available in codes. The ultimate limit state was addressed by providing strength capacity that limit ductility demand to their safe flexural displacement capacity. The strength demands were derived from ground motion spectra using modification factors that depend on both the strength and energy absorption of the structure. Deformation capacity was derived by proposing new definitions for elastic (virtual yield) displacement and maximum allowable displacement. Strength modification factor was proposed based on the test results. The occurrence of "virtual plastic hinge" for GFRP-reinforced shear walls was described providing new definitions convenient with the behavior of the GFRP-reinforced shear walls. "Virtual plastic hinge" length was estimated based on observations and calculations. Subsequently, the experimental results were used to justify the proposed design procedure. The promising results could provide impetus for constructing shear walls reinforced with GFRP bars and constitute a step toward using GFRP reinforcement in such lateral-resisting systems.
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Foundoukos, Nickolaos. "Behaviour and design of steel-concrete-steel sandwich construction." Thesis, Imperial College London, 2005. http://hdl.handle.net/10044/1/8819.
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Lefas, Ioannis. "Behaviour of reinforced concrete structural walls and its implication for ultimate limit state design." Thesis, Boston Spa, U.K. : British Library Document Supply Centre, 1988. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.283581.
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Al-Rubaye, Salam Adil. "Experimental and Simplified Analytical Investigation of Full Scale Sandwich Panel Walls." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6825.
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Concrete sandwich wall panels have been used for decades in the precast concrete construction industry because of their thermal efficiency. To achieve full or partial-composite action in concrete sandwich panel walls, the engineer must obtain a percent composite action from a connector manufacturer, making some engineers uncomfortable. Engineers are dependent upon the recommendations given by the connector manufacturers to establish their designs. This project tested six full scale sandwich panel walls to evaluate the percent composite action of various connectors and compare the results to those provided by the composite connector manufacturers.
This project aimed to validate current procedures using these methods, and to develop simpler, more efficient methods for predicting overall strength of this innovative building system. This study concluded that the reported degrees of composite action from each manufacturer are considered conservative in all instances for the connectors tested. Additionally, the intensity and type of connectors are important factors in determining the degree of partial composite action in a panel.
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Kazaz, Ilker. "Dynamic Characteristics And Performance Assessment Of Reinforced Concrete Structural Walls." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611712/index.pdf.
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The analytical tools used in displacement based design and assessment procedures require accurate strain limits to define the performance levels. Additionally, recently proposed changes to modeling and acceptance criteria in seismic regulations for both flexure and shear dominated reinforced concrete structural walls proves that a comprehensive study is required for improved limit state definitions and their corresponding values. This is due to limitations in the experimental setups, such that most previous tests used a single actuator at the top of the wall, which does not reflect the actual loading condition, and infeasibility of performing tests of walls of actual size in actual structural configuration. This study utilizes a well calibrated finite element modeling tool to investigate the relationship between the global drift, section rotation and curvature, and local concrete and steel strains at the extreme fiber of rectangular structural walls. Functions defining more exact limits of modeling parameters and acceptance criteria for rectangular reinforced concrete walls were developed. This way a strict evaluation of the requirements embedded in the Turkish Seismic Code and other design guidelines has become possible. Several other aspects of performance evaluation of structural walls were studied also. Accurate finite element modeling strategies and analytical models of wall and frame-wall systems were developed for seismic response calculations. The models are able to calculate both the static and dynamic characteristics of wall type buildings efficiently. Seismic responses of wall type buildings characterized with increasing wall area in the plan were analyzed under design spectrum compatible normal ground motions.
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Fall, Niklas, and Viktor Hammar. "Design of Perimeter Walls in Tubed Mega Frame Structures." Thesis, KTH, Betongbyggnad, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147242.
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The Tubed Mega Frame is a new concept for constructing high-rise buildings,based on the idea of moving the main bearing system to the perimeter of thebuilding by using a number of large hollow columns, mega tubes, connected byperimeter walls at certain levels. The concept is under development by Tyréns ABand has not yet been implemented in reality. This thesis is part of the ongoing workprocess and has the aim of shedding light on the issues and problems with the newconcept when it comes to the perimeter walls. The perimeter walls are an essential part of the Tubed Mega Frame structure sincethey provide the main lateral stability of the structure by connecting the mega tubesand transferring lateral loads between them. It is therefore of big importance thatthe walls are designed and constructed to withstand all the loads they wouldpossibly be exposed to.In this thesis a perimeter wall in a prototype building of the Tubed Mega Framehave been analysed, designed and tested using non-linear FE-analysis in the pursuitof create a better understanding in how the perimeter walls works and should bedesigned. To begin with, a global analysis was performed to obtain the forces acting on themost critical perimeter wall. The stresses in the wall were then analysed in order tocreate an appropriate strut-and-tie model used to determine the reinforcementdesign for the specified perimeter wall. The perimeter wall was designed for amaximum shear force of 14.5 MN and corresponding moment of 87 MNm usingstrut-and-tie model according to American standards, ACI 318-11. The final step was to verify the design using the non-linear FE-analysis programATENA. A model of the reinforced wall was analysed with two different loadcases; one were the resistance was determined by unidirectional deformation untilfailure and one were the effects of cyclic loading was considered by initialdeformation corresponding to service loads prior to failure loading. The resistanceobtained from the first load case was 46.8 MN and for the second 19.1 MN usingmean values for material properties. In order to obtain a design resistance of the wall in the non-linear analysis, a globalsafety factor was determined by using the ECOV method. The design resistance were 39.9 and 13.5 for the two load cases respectively.Tubed Mega Frame (TMF) är ett nytt koncept för att bygga höghus som bygger påidén om att flytta det bärande systemet till omkretsen av byggnaden med hjälp avett antal stora ihåliga pelare, megatuber, anslutna med omslutande tvärväggar påvissa våningsplan. Konceptet är under utveckling av Tyréns AB och har ännu integenomförts i verkligheten. Detta examensarbete är en del i den pågående processenoch målet är att belysa frågor och problem som finns med det nya konceptet närdet gäller de omslutande tvärväggarna. De omslutande tvärväggarna är en vital del av Tubed Mega Frame eftersom debidrar till huvudsakliga sidostabiliteten i byggnaden genom att sammankopplamegatuberna och överföra horisontalkrafter mellan dem. Det är därför av stor viktatt väggarna är konstruerade och tillverkade för att stå emot alla de belastningarsom de skulle kunna vara utsatta för. I detta examensarbete har en tvärvägg i en prototypbyggnad för Tubed MegaFrame analyserats, dimensionerats och testats med syftet att bidra till en bättreförståelse för hur tvärväggarna fungerar och bör utformas. Till att börja med har en global analys utförts för att erhålla de krafter som verkarpå den mest kritiska tvärväggen. Spänningarna i väggen analyserades sedan för attskapa en lämplig fackverksmodell som sedan användes för att bestämmaarmeringsutformning för den specificerade tvärväggen. Väggen dimensioneradesför en maximal tvärkraft på 14,5 MN och ett motsvarande moment på 87 MNmgenom att använda fackverksmetoden enligt amerikanska standarder, ACI 318-11. Det sista steget var att kontrollera konstruktionen med hjälp av det ickelinjära FE-analysprogrammet ATENA. En modell av den armerade väggen analyserades medtvå olika lastfall. I det första lastfallet genom att i en riktning deformera väggen tillbrott. I det andra lastfallet beaktades tidigare uppsprickning genom att först belastaväggen med en deformation motsvarande dess brukslast och sedan belasta väggen imotsatt riktning tills brott uppstod. Bärförmågan var 46,8 MN och 19,1 MN förrespektive lastfall, beräknat med medelvärden för materialegenskaper. För att erhålla en dimensionerande bärförmåga för väggen ur den ickelinjäraanalysen bestämdes en global säkerhetsfaktor med hjälp av ECOV-metoden.Dimensionerande bärförmåga var 39,9 MN och 13,5 MN för respektive lastfall.
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Navarro, Cota Juan Pedro Martin 1963. "DESIGN AND BEHAVIOR OF COMPOSITE SPACE TRUSSES." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276505.
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A fully automated computer program is developed for the optimum design of steel space trusses acting compositely with a concrete slab placed on top. The program sizes the truss members to meet the requirements of the load and resistance factor design specification of the American Institute of Steel Construction using the load combinations of ANSI. Earthquake loading is not considered. The optimum size is based on minimum cost, regarding the amount of welding required at the joints and of the member itself. The total cost is based on all steel work in the truss. Once the truss configuration has been defined, and it has been ensured that linear elastic behavior exists, the structure is analyzed for the construction process, to make sure that no overstressing will take place in any structural element at any time during construction and service. The analysis and design principles are presented and an actual design case is solved. (Abstract shortened with permission of author.)
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Joy, Westin T. "Concrete capacity design of the Cazaly hanger." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1799711381&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Aguero, Patrick I. R. "Concrete tilt-up in residential construction: innovative energy efficient design." Thesis, Aguero, Patrick I.R. (1995) Concrete tilt-up in residential construction: innovative energy efficient design. Masters by Research thesis, Murdoch University, 1995. https://researchrepository.murdoch.edu.au/id/eprint/38169/.
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Tilt-up construction features the use of factory or site cast (not precast) reinforced concrete panels that are tilted about one edge and/or lifted into position to form the walls of a building. This method of construction benefits the builder by offering time and cost savings. It is also attractive to architects because of the variety of surface finishes and panel shapes that can be achieved. Due to this versatility, Tilt-up construction has evolved from its beginnings in factory buildings to sophisticated commercial and multi-unit residential construction.
With the continuing growth in Tilt-up construction, there is a need to assess the potential benefits to the home owner of an energy efficient design using the thermal mass properties of concrete Tilt-up panels. Tilt-up will reach its full potential as an energy efficient form of construction when the short term cost savings to the builder are combined with the long term energy savings to the home owner.
The objective of this work is to undertake an innovative energy efficient design of a residential Tiltup building in the form of a fully detached single storey house. The project will assess the benefits and the problems of combining residential Tilt-up construction with energy efficient design principles by comparing the results to a conventional design approach.
Specific objectives include:
• Identification of design elements of energy efficient design and tilt-up construction,
• Development of performance indicators to optimise the design and assess the relative benefits and costs of combining energy efficient design and tilt-up construction,
• Selection of a proven energy efficient house based on a conventional design approach,
• Design of an appropriate Tilt-up construction method for the selected energy efficient house, and
• Optimisation of the design by the application of performance indicators to the design elements.
In the first instance, it is necessary to determine an appropriate design strategy that will meet the above objectives. The work involves the design of a fully detached single storey house in Perth, Western Australia. Therefore, the design strategy must be relevant to Perth's climatic, social, political and economic conditions. In this light, an Australian rather than an overseas based approach, provides the most appropriate starting point for the research and design task. Developments overseas are assessed with respect to specific design tools and options that may enhance the flexibility, results and applicability of the adopted design approach.
Section 2 develops the design strategy for an energy efficient design of a fully detached single storey house incorporating Tilt-up construction. Design strategies in use in Australia that achieve the separate objectives of energy efficient design and Tilt-up construction are identified and specific design. tools and options are assessed. In particular, strengths, weaknesses, limitations and assumptions of available strategies are discussed with respect to the above objectives. A design strategy combining the objectives of energy efficient design and Tilt-up construction is developed together with a consolidated list of common and exclusive design elements. In addition, a multi-objective assessment criteria in the form of performance indicators is introduced to optimise and assess the design.
Once the design strategy is developed, it is then necessary to determine how each design element is judged by the assessment criteria. Section 3 develops the assessment framework by assigning, where appropriate, quantitative or qualitative measures to the performance indicators. This establishes the mechanism by which each design element is addressed in terms of the performance indicators. Factors that conflict with, or complement other performance indicators are identified and where possible, quantified. Where required, trade-offs are assessed and adopted. In this way the design task is optimised and assessed in an iterative process to meet the assessment criteria.
Section 4 details the design of the Tilt-up house, including optimisation of design elements to meet
performance indicators. The selection criteria for a proven energy efficient design to form the base case design is outlined. In addition, the results of the conversion from conventional to Tilt-up construction are discussed and guiding strategies that provide opportunities for further optimisation are identified. Finally, the results of applying appropriate guiding strategies to further optimise the base case design are detailed. It is important to note that due to professional liability limitations on the author, only a preliminary structural design is attempted in this work. If the house is to be constructed, then this will require a detailed structural design that will be the responsibility of an independent professionally certified structural engineer.
Section 5 summarises the results of optimising the design and discusses the extent to which each performance indicator has been met. Specifically, the benefits and costs of combining energy efficient design with Tilt-up construction are assessed.
Section 6 draws a number of conclusions and makes recommendations for the application of the results and for further work based on the results discussed in Section 5.
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West, Jeffrey Steven. "Durability design of post-tensioned bridge substructures /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Vogt, Carsten. "Ultrafine particles in concrete : Influence of ultrafine particles on concrete properties and application to concrete mix design." Doctoral thesis, KTH, Betongbyggnad, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12161.
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Betaque, Andrew D. "Evaluation of software for analysis and design of reinforced concrete structures." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09192009-040235/.
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Camann, Kevin Robert. "Design and Performance of Load Bearing Shear Walls Made from Composite Rice Straw Blocks." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/218.
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Although rice straw and other grains have been used in building since pre-history, in the past two decades, there has been a move to utilize this rapidly renewable, locally available, agricultural byproduct as part of the sustainable construction movement. Up to this point, this has been done by simply stacking up the full straw bales. Stak Block, invented by Oryzatech, Inc., is a modular, interlocking block made of a composite of rice straw and binding agent that serves as an evolution in straw construction. This study investigates the feasibility of using these Stak Blocks as a structural system. The report was divided into four main parts: material testing, development of effective construction detailing, full-scale physical shear wall testing, and a comparison with wood framed shear walls.
The first section investigated the feasibility of using the Stak Blocks in a load-bearing wall application. Constitutive properties of the composite straw material such as yield strength and elastic stiffness were determined and then compared to conventional straw bale. Next, the decision was made to prestress the walls to create a more effective structural system. Various construction detailing iterations were evaluated upon the full-scale shear wall testing using a pseudo-static cyclic loading protocol. Finally, the available ductility of the prestressed Stak Block walls in a lateral force resisting application is quantified along with an approximation of potential design shear forces.
It was determined that the Stak Block material performed satisfactorily in gravity and lateral force resisting applications, in some respects better than conventional wood-framed construction, and has great potential as a seismically-resistant building material.
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黃崑 and Kun Huang. "Design and detailing of diagonally reinforced interior beam-column joints for moderate seismicity regions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31244233.
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Malyszko, Thomas E. "The nonlinear response of reinforced concrete coupling slabs in earthquake-resisting shearwall structures /." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66183.
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Buchberg, Brandon S. "Investigation of mix design and properties of high-strength/high-performance lightweight concrete." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/23394.
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Tovi, Shivan. "Deflection of concrete slabs : current performance & design deflection limits." Thesis, University of West London, 2017. https://repository.uwl.ac.uk/id/eprint/3836/.
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Deflection is usually controlled by limiting the span/depth ratio. One aspect of this research is to document the deflection of a concrete slab in a large residential block. The other part of the research is to look at current design limits. Limits on deformation were set many decades ago, when the forms of construction, partitions, finishing, cladding and service were very different from what they are now. Part of that is to review the span-to-depth method of design. Site investigation and testing theory through observation and data collection was the main deductive approach of this research. A quantitative method was used to calculate and determine the deflection on concrete slabs, the research is attempted to identify target companies and projects to participate in the research. The data indicate that the slab has not sagged significantly due to the back propping for 30 days. However, it does seem that the slab was sloping down from the corner by 6 mm diagonally across the 12m bay. A margin of deflection around 2mm occurred especially in the mid-span of the slab 12 x 7 m corner bay. The 2 mm deflection occurred at the beginning of the investigation after back propping reinforced concrete corner bay slab. The back propping applied after 7 days of pouring slab.
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Wong, Anthony K. M. "Theoretical investigation of Australian designed reinforced concrete frames subjected to earthquake loading /." Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09ENS/09ensw872.pdf.
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Mostert, Louwrens Hubert. "Design and construction preferences for connections in the precast concrete industry of South Africa." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96036.
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Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Precast concrete has been used for decades in the construction industry, locally as well as internationally. Rapid urban development and the need for shorter construction periods for building and infrastructure projects have however encouraged more use of precast concrete construction. The improved speed of construction, high quality and less labour requirements that precast offers makes it an effective type of construction method for modern development. The utilization of various precast concrete systems has been frequently used in the international construction industry, making it a very popular construction method. It was however found that one of the major drawbacks or concerns with the use of precast concrete is the connections between the precast elements. In-situ construction does not have this problem, because it is designed to a monolithic structure or building. It was identified that if the connections in precast buildings or structures are designed or constructed in an insufficient way, it can lead to severe structural problems and even failure. This highlights the importance the design and construction of precast concrete connections have on the overall stability, strength and robustness of the structure. Precast concrete buildings are not merely separate precast elements, connected together to eventually form the same principals of in-situ construction. Precast concrete and connection design is considered to be a specialist field and requires the sufficient expertise and knowledge to understand the structural system and all its different aspects. The precast connection’s function is not merely to transfer loads, but also to develop continuity and ensure monolithic behaviour of the entire precast concrete structure (Englekirk 2003). The most important or desirable structural functions of precast connections are; (i) direct transfer of loads (load paths and flow or forces), (ii) develop structural continuity and integrity, (iii) distribution of concentrated loads, (iv) allow for movements and unintended restraints and lastly to (v) ensure efficient rigidity and robustness for the connection. It can be seen that there is many factors that contribute to the overall design and construction phases of precast concrete connections. The aim of this study is to identify and investigate aspects that influence the design and construction of precast concrete connections. This study will mainly focus on precast concrete and precast connection preferences of participants in the South African construction industry. During this study, industry participants (contractors and consultants) were asked to identify certain aspects and concerns associated with precast concrete and precast connection construction. These answers were used to develop guidelines and preferences that can be used by industry participants to improvise and effectively manage the precast construction, mainly focussing on the connections between the precast elements.
AFRIKAANSE OPSOMMING: Voorafvervaardigde beton word al vir dekades gebruik in die konstruksiebedryf, plaaslik sowel as internasionaal. Vinnige stedelike ontwikkeling en die behoefte vir korter konstruksie tydperke vir die struktuur en infrastruktuur projekte het egter die gebruik en implementasie van voorafvervaardigde beton konstruksie laat toeneem. Die verbeterde spoed van die konstruksie proses, 'n hoë gehalte produk en minder arbeid vereistes wat voorafvervaardiging bied maak dit dus 'n effektiewe tipe konstruksie metode vir moderne ontwikkelings. Die benutting van verskeie voorafvervaardigde beton sisteme en elemente word reeds herhaaldelik gebruik in die internasionale konstruksiebedryf, wat dit vervolglik ʼn baie populêre en effektiewe sisteem maak. Dit is egter bevind dat een van die groot struikelblokke of probleme met die gebruik van voorafvervaardigde beton is die verbindings tussen die voorafvervaardigde elemente. In-situ beton konstruksie het dus nie hierdie probleem nie, want dit word ontwerp om 'n monolitiese beton struktuur of gebou te vorm. Dit was immers geïdentifiseer dat as die verbindings in ʼn voorafvervaardigde gebou of struktuur, ontwerp word deur ʼn ontoereikende manier, dit kan lei tot ernstige strukturele probleme en selfs strukturele faling. Dit beklemtoon dus die belangrikheid wat die ontwerp en konstruksie proses van voorafvervaardigde beton verbindings het op die algehele stabiliteit, sterkte en robuustheid van die struktuur. Voorafvervaardigde beton geboue en strukture kan nie slegs beskou word as aparte voorafvervaardigde elemente wat met mekaar verbind word om eventueel dieselfde beginsels van insitu konstruksie te vorm nie. Voorafvervaardigde beton en verbinding ontwerp word beskou as 'n spesialis veld en vereis dat die ontwerper die nodige kundigheid en kennis van die strukturele stelsel en al sy verskillende aspekte verstaan. Voorafvervaardigde beton verbindings se funksie is nie net om toegepaste kragte oor te dra nie, maar ook om strukturele kontinuïteit te ontwikkel en te verseker dat monolitiese gedrag gehandhaaf word vir die hele voorafvervaardigde beton struktuur (Englekirk 2003). Die mees belangrike strukturele funksies van voorafvervaardigde beton verbindings sluit die volgende in; (i) verseker direkte oordrag van toegepaste kragte (vloei van kragte), (ii) ontwikkeling van strukturele kontinuïteit en integriteit, (iii) die verspreiding van puntbelastings, (iv) moet voorsiening maak vir die bewegings in die voorafvervaardigde element en konneksie self en laastens (v) verskaf doeltreffende rigiditeit en robuustheid vir die konneksie sone. Dus kan daar afgelei word dat daar baie faktore is wat bydra tot die algehele ontwerp en konstruksie fases van voorafvervaardigde beton verbindings. Die doel van hierdie studie is om aspekte te identifiseer en te ondersoek wat die ontwerp en konstruksie van aspekte beton verbindings wel beïnvloed. Die studie sal hoofsaaklik fokus op voorafvervaardigde beton en verbindings voorkeure van persone in die Suid-Afrikaanse konstruksiebedryf. Tydens die studie was persone in die industrie (kontrakteurs en konsultante) ook gevra om sekere aspekte en kwellings wat verband hou met voorafvervaardigde beton asook die verbindings te identifiseer. Die antwoorde wat verkry was uit die industrie deelnemers kan toepaslik gebruik om word riglyne en voorkeure op te stel wat vervolglik gebruik en toegepas kan word in die konstruksie bedryf van Suid Afrika. Die riglyne kan effektief gebruik word om voorafvervaardigde beton asook die verbindings te verbeter en persone in die konstruksie bedryf in te lig oor voorkeure en toepassings van hierdie metode.
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Gao, Bo. "FRP strengthened RC beams : taper design and theoretical analysis /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?MECH%202005%20GAO.
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Kim, Haena. "Design and field construction of Hawkeye Bridge using ultra high performance concrete for accelerated bridge construction." Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/3117.
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The Ultra High Performance Concrete (UHPC) consists of sand, cement, crushed quartz, silica fume, superplasticizer, water and steel fibers, with water-to cement (w/c) ratio of 0.24 or lower. By omitting coarse aggregates in the mix, density and mechanical homogeneity can be maximized. Also, adding steel fibers increases durability by producing exceptionally high compressive and tensile strengths. As a result, a bridge using UHPC can be designed slimmer and longer with less amount of steel reinforcements than a conventional concrete bridge. UHPC developed by Korea Institute of Civil Engineering and Building Technology (K-UHPC) was used to build a bridge, named “Hawkeye”, in Buchanan County, Iowa. This paper describes the design and construction process of the Hawkeye bridge which is the first bridge using K-UHPC in the United States. A unique pi-girder design, which is similar to the design previously developed at MIT, was adopted for the Hawkeye Bridge. The Hawkeye Bridge was successfully constructed using K-UHPC, utilizing local cement, sand and ready-mix trucks. Precast pi-girders were made at the Buchanan County, 17 miles (27 km) from the bridge site. A total of six girders were transported to the bridge site and installed in one day. This project not only demonstrated easy field constructability of K-UHPC but also set a great example of Accelerated Bridge Construction (ABC), which would minimize a traffic disruption.
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Goede, William Gunter. "Pervious concrete investigation into structural performance and evaluation of the applicability of existing thickness design methods /." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/w_goede_112409.pdf.
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Thesis (M.S. in civil engineering)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 22, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 98-102).
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Zou, Xiaokang. "Optimal seismic performance-based design of reinforced concrete buildings /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202002%20ZOU.
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Dvořák, Vít. "Bytový dům na ul. Vinohrady." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265648.
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The master´s thesis is focused on a design of monolithic reinforced concrete construction of an apartment building. The content of this work is design of two ceiling slabs, staircase, supporting columns, walls, girders and concrete pile construction of foundation. Thesis includes working-out of static calculation, elaboration drawing of shape, reinforcement of solved elements and evolvement of assembly drawings. The rest of the project parts are not analysed.
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Guney, Murat Efe. "A Numerical Procedure For The Nonlinear Analysis Of Reinforced Concrete Frames With Infill Walls." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606318/index.pdf.
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Materially non-linear analysis of reinforced concrete frame structures with infill walls requires appropriate mathematical models to be adopted for the beams and the columns as well as the infill walls. This study presents a mathematical model for frame elements based on a 3D Hermitian beam/column finite element and an equivalent strut model for the infill walls. The spread-of-plasticity approach is employed to model the material nonlinearity of the frame elements. The cross-section of the frame element is divided into triangular sub regions to evaluate the stiffness properties and the response of the element cross-section. By the help of the triangles spread over the actual area of the section, the bi-axial bending and the axial deformations are coupled in the inelastic range. A frame super-element is also formed by combining a number of frame finite elements.
Two identical compression-only diagonal struts are used for modeling the infill. The equivalent geometric and material properties of the struts are determined from the geometry of the infill and the strength of the masonry units
A computer code is developed using the object-oriented design paradigm and the models are implemented into this code. Efficiency and the effectiveness of the models are investigated for various cases by comparing the numerical response predictions produced by the program with those obtained from experimental studies.
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Reperant, Jefferey John Robert. "Studies of turbulent liquid sheets for protecting IFE reactor chamber first walls." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/18921.
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Chen, Mantai, and 陈满泰. "Combined effects of strain gradient and concrete strength on flexural strength and ductility design of RC beams and columns." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206429.
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The stress-strain relationship of concrete in flexure is one of the essential parameters in assessing the flexural strength and ductility of reinforced concrete (RC) structures. An overview of previous research studies revealed that the presence of strain gradient would affect the maximum concrete stress and respective strain developed in flexure. Previously, researchers have conducted experimental studies to investigate and quantify the strain gradient effect on maximum concrete stress and respective strain by developing two strain-gradient-dependent factors k3 and ko for modifying the flexural concrete stress-strain curve.
In this study, the author established a new analytical concrete constitutive model to describe the stress-strain behavior of both normal-and high-strength concrete in flexure with the effect of strain gradient considered. Based on this, comprehensive parametric studies have been conducted to investigate the combined effects of strain gradient and concrete strength on flexural strength and ductility design of RC beams and columns with concrete strength up to 100 MP a by employing the strain-gradient-dependent concrete stress-strain curve using non-linear moment-curvature analysis.
From the results of the parametric studies, it is evident that both the flexural strength and ductility of RC beams and columns are improved under strain gradient effect. A design value of ultimate concrete strain of 0.0032and anew equivalent rectangular concrete stress block incorporating the combined effects of strain gradient and concrete strength have been proposed and validated by comparing the proposed theoretical strength with the strength of 198 RC beams and 275 RC columns measured experimentally by other researchers. It is apparent from the comparison that the proposed equations can predict more accurately the flexural strength of RC beams and columns than the current RC design codes.
Lastly, for practical engineering design purpose, design formulas and charts have been produced for flexural strength and ductility design of RC beams and columns incorporating the combined effects of strain gradient and concrete strength.published_or_final_version
Civil Engineering
Master
Master of Philosophy
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Ho, Ching-ming Johnny, and 何正銘. "Design and detailing of high strength reinforced concrete columns in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31224398.
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Takács, Peter F. "Deformations in Concrete Cantilever Bridges : Observations and Theoretical Modelling." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-112.
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The thesis deals with the deformation problem of segmental, cast-in-place concrete cantilever bridges. This type of bridge has shown some propensity to develop larger deflections than those were predicted in the design calculation. Excessive deflections may lead to deterioration of aesthetics, serviceability problems and eventually early reconstruction of the bridge. Also in the construction stages the deflections have to be properly compensated to achieve the smooth camber in the completed bridge deck.
Deformation prediction in concrete cantilever bridges is not as reliable as it would be necessary due to several factors. The high degree of uncertainty in creep and shrinkage prediction in concrete constitutes the major difficulty. Other factors are the complex segmental construction procedure and the sensitivity of the deformations to variations in the construction schedule, the uncertainty in estimating the frictional loss of prestress and relaxation in the prestressing tendons and uncertainty in estimating model parameters such as temperature and relative humidity.
The doctoral study was initiated with the objective to improve deformation prediction in segmentally cast concrete cantilever bridges and to establish guidelines for deformation analysis based on advanced numerical methods.
A database on observed deformations in three modern long span concrete cantilever bridges in Norway has been established. Two of the bridges were partly constructed from lightweight aggregate concrete. The deformations have been monitored since the construction stages up to the present time. The measurements cover the construction stages and the service life of 14, 8 and 3 years, respectively for the three bridges. The measured deformations are deflections in the superstructure and in one of the bridges, also strain measurements in the piers and the superstructure.
A sophisticated numerical model was created for deformation analysis. The numerical model realistically simulates the segmental construction procedure and the entire life span of the bridge. The effects of the segmental construction method, temporarily supports and constraints and changes in the structure system during construction are taken into account. The model considers the different concrete age from segment to segment, the sequential application of permanent loads and prestressing and the effect of temporary loads. The prestressing tendons are individually modelled with their true profile taking into account the variation of the effective prestressing force along the length of the tendon and with time.
The finite element model consists of beam elements which are based on an advanced beam element formulation. The beam model was verified against a robust two-and-a-half dimensional shell model concerning its general performance and some specific issues. The comparison confirmed the accuracy of the beam model. Existing experimental data on creep and shrinkage in lightweight aggregate concrete and high strength concrete were evaluated in comparison with theoretical models. The main focus was on the CEB-FIP Model Code 1990 and its subsequent extensions. The findings were considered in the numerical studies.
Deformations of the three bridges were computed. The CEB-FIP Model Code 1990 material model was used for concrete for the most part. The elastic moduli were taken from test results where they were available. The creep coefficient and the shrinkage strain of the lightweight aggregate concrete were assumed equal to those of normal density concrete of the same strength. The agreement between the calculated and the measured deformations were satisfactory in view of the large uncertainty involved in theoretical prediction. While moderate differences were observed in most cases, no clear overall tendency toward underor overestimation was found. In subsequent numerical studies, the sensitivity of the deformations to variations in various model parameters was investigated. The B3 model was compared to the CEB-FIP Model Code 1990 in the analysis of one of the bridges, where the latter model showed somewhat better agreement with the measurements.
The last part of the work concerned a robust probabilistic analysis which was based on a Monte Carlo simulation. The objective of the probabilistic analysis was to estimate the statistical properties of the deformation responses. With the distribution function of a given deformation response being known, the confidence limit for the deformation can be determined. It is recommended to design the bridge for the long-time deflection which represents a certain confidence limit (e.g. the 95 % confidence limit) of the response rather than its mean. Such way the risk that the bridge will suffer intolerable deflection over its life span can be minimised.