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Trygstad, Steinar. "Structural Behaviour of Post Tensioned Concrete Structures : Flat Slab. Slabs on Ground." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-114.
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In this investigation strength and structural behaviour of prestressed concrete is studied with one full scale test of one flat slab, 16000 mm x 19000 mm, and three slabs on ground each 4000 mm x 4000 mm with thickness 150 mm. The flat slab was constructed and tested in Aalesund. This slab has nine circular columns as support, each with diameter 450 mm. Thickness of this test slab was 230 mm and there were two spans in each direction, 2 x 9000 mm in x-direction and 2 x 7500 mm in y-direction from centre to centre column. The slab was reinforced with twenty tendons in the middle column strip in y-direction and eight tendons in both outer column strips. In x-direction tendons were distributed with 340 mm distance. There were also ordinary reinforcement bars in the slab. Strain gauges were welded to this reinforcement, which together with the deflection measurements gives a good indication of deformation and strains in the structure.
At a live load of 6.5 kN/m2 shear failure around the central column occurred: The shear capacity calculated after NS 3473 and EuroCode2 was passed with 58 and 69 %, respectively. Time dependent and non-linear FE analyses were performed with the program system DIANA. Although calculated and measured results partly agree well, the test show that this type of structure is complicated to analyse by non-linear FEM.
Prestressed slabs on ground have no tradition in Norway. In this test one reinforced and two prestressed slabs on ground were tested and compared to give a basis for a better solution for slabs on ground. This test was done in the laboratory at Norwegian University of Science and Technology in Trondheim. The first slab is reinforced with 8 mm bars in both directions distributed at a distance of 150 mm in top and bottom. Slab two and three are prestressed with 100 mm2 tendons located in the middle of slab thickness, and distributed at a distance of 630 mm in slab two and 930 mm in slab three. Strain gauges were glued to the reinforcement in slab one and at top and bottom surface of all three slabs. In slab two and three there were four load cells on the tendons.
Each slab were loaded with three different load cases, in the centre of slab, at the edge and finally in the corner. This test shows that stiffness of sub-base is one of the most important parameters when calculating slabs on ground. Deflection and crack load level depends of this parameter. Since the finish of slabs on ground is important, it can be more interesting to find the load level when cracks start, than deflection for the slab. It is shown in this test that crack load level was higher in prestressed slabs than in reinforced slab. There was no crack in the top surface with load in the centre, but strain gauges in the bottom surface indicate that crack starts at a load of 28 kN in the reinforced slab, and 45 kN in the prestressed slabs. Load at the edge give a crack load of 30 kN in reinforced slab, 45 kN and 60 kN in prestressed slabs. The last load case gives crack load of 30 kN in reinforced slab, 107 kN and 75 kN in prestressed slabs. As for the flat slab, FE analyses were performed for all of the three slabs on ground, and analyses shows that a good understanding of parameters like stiffness of sub-base and tension softening model, is needed for correct result of the analyses.
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Shao, Xiao-yun. "Punching shear strength of reinforced concrete slab." Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/10727.
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This thesis presents the results of punching shear tests performed on a 2 x 2 bay continuous slab with/and without supplementary supports. On the basis of these tests, the code method of calculating the ultimate strength of interior, edge and corner column connections of flat slab were investigated. The thickness of the specimen was 140 mm and the spans length were 2743 mm. The ACI 318-89, BS 8110-85 and CEB-FIP 90 Codes were critically reviewed by comparing with the experiment results and results from the literature. It was found that in general the Code predictions are reasonable but for corner column connections the ACI Code over-estimates the ultimate shear capacity of the slab and BS 8110-85 requirements for edge and corner column connections are simplistic. The experimental results show that the supplementary supports can increase the ultimate punching shear capacity when the supports are properly located.
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Menez, Martin Herve. "Efficiency of a fabric formed concrete slab." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104241.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016.Cataloged from PDF version of thesis. Page 123 blank.
Includes bibliographical references (pages 121-122).
The built environment is responsible for approximately 50% of the carbon emissions on the planet. Therefore, it is of major importance to reduce the carbon footprint of our structures to better preserve our environment for future generations. Furthermore, studies demonstrate that flooring systems can be responsible for 70% of material consumption in high rise buildings, and about the same proportion of embodied carbon energy. Based on these considerations, this thesis suggests a new form of concrete slab and quantifies its efficiency in terms of material, carbon energy and cost savings compared to a traditional reinforced concrete flooring system. The proposed form of concrete slab is constructed using fabric formwork. It provides the flexibility and ease of construction needed to build such a low-volume structural shape. After establishing that this slab can be about 50% lighter than a traditional reinforced concrete slab, the thesis models and quantifies the savings in other parts of the structure and shows that the embodied carbon footprint of the entire building can be reduced by approximately 50%. Keywords: Concrete slab - Compression only - Fabric-formworks - Carbon energy
by Martin Herve Menez.
M. Eng.
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Bengtsson, Pär, and Johan Wallin. "Analysis of a Prefabricated Concrete Skew Angle Slab Bridge." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-81146.
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Prefabricated concrete elements are widely used in the construction industry today. With advantages such as time savings, increased safety at the construction site and minimized material usage, prefab becomes a major challenger to the traditional on-site casting construction method. However, constructing a bridge in concrete still presents challenges when using prefab as a construction method. Hence, more research in the area is needed. This master thesis has been studying the behavior of a prefabricated skew angle slab and the connection between the slab and wall elements of a bridge. The study was conducted using a finite element software, where three 3D-models of skew angle slabs were created. The three models had different skew angles (0, 15 and 30 degrees) and crossed the same path. The models could represent both the slab and the slab-wall connection. The finite element analysis showed that slabs with angles up to 15 degrees could be designed as a straight bridge. However, when the skew angle increases to 30 degrees, the behavior of the slab and connection changes significantly. Furthermore, the results show that a stress concentration occurs in the obtuse corner and that the stress increases when the skew angle increases. Moreover, there is a slight uplift in the acute corner when the skew angle increases to 30 degrees.
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Russell, Justin. "Progressive collapse of reinforced concrete flat slab structures." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/28991/.
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In 1968 a relatively small gas exposition on the 18th floor of the Ronan Point tower building resulted in the partial collapse of the structure. This event highlighted that progress collapse may occur to structures under an accidental loading event. Other events, including the bombing of the Murrah federal building in 1993 in Oklahoma, have resulted in the common design requirement that a structure be capable of surviving the removal of a load bearing element. This approach, often referred to as the sudden column loss scenario, effectively ignores the cause of the damage and focuses on the structure’s response afterwards. The refinement of the analysis varies, with options to include the nonlinear and dynamic behaviours associated with extreme events, or to use simplified linear and static models with factors included to account for the full behaviour. Previous research into progressive collapse has highlighted that providing ductility in the connections, and avoiding brittle failures, is important in ensuring the structure maintains integrity after a column loss event. However, the majority of this work has been focused on the behaviour of steel and Reinforced Concrete (RC) frame structures. As flat slab construction is a popular method for many structures, due to the flexibility it offers for layouts and its low storey heights, it is an important to consider flat slab behaviour in more detail. Furthermore, slab elements behave differently to frame structures due to the Alternative Load Paths (ALPs) that can develop after a column loss via two-dimensional bending mechanisms. Additionally, punching shear failure is a known issue due to the thin section depths. This work addresses the issue of the response of RC flat slab structures after a sudden column loss. As previous case studies have demonstrated that brittle failures may lead to progressive collapse of such structures, a complete understanding of the response is required. The nonlinear behaviour of a slab structure, due to both material and geometric factors, is investigated to determine the additional capacity available beyond the usual design limits. Additionally, the dynamic factors involved, primarily due to inertial effects, are also considered. To achieve this, experimental and numerical studies were conducted. A series of 1/3 scale models of slab substructures were constructed to replicate column loss events. Two types of tests were conducted, a static push down test with a support removed and a sudden dynamic column removal case. Displacements, strains and support reactions were recorded throughout, along with cracking patterns. For the dynamic tests a high speed camera was used to obtain the deflection response in the short time period after removal and to observe the formation of cracks. Comparisons between the two cases allowed determination of the dynamic effects on the response of the system. The experimental programme was then replicated using a Finite Element (FE) model. The results taken from the experimental case were used to validate the material and modelling assumptions made during the numerical simulations. This validated model was finally used to investigate a wider range of variables and assess the response of typical structural arrangements, with particular focus on the nonlinear and dynamic factors involved after a sudden column loss. The experimental and numeral investigations demonstrated that after the loss of a column, flat slab structures can maintain integrity due to a change in the load paths away from the removal location. Although in some cases a large amount of flexural damage to the concrete and reinforcement occurred, such effects did not lead to complete failure. However, during the experimental programme some punching shear failures occurred, usually at the corner column locations. From the numerical analysis, shear forces of over twice the fully supported condition occurred as a result of removing a column, which may exceed the designed capacity. Comparisons between a static and dynamic analysis provides information into a suitable Dynamic Amplification Factor (DAF) for use with simplified modelling approaches. Based on the range of structures considered, the maximum increase in deflections as a result of a sudden removal was 1.62 times the static case, this is less than the commonly used factor of 2.0. Additionally, this factor reduces as the nonlinearity increases due to further damage, with a smallest DAF calculated at 1.39. This factor can be reduced further if the column is not removed instantaneously. Finally, the material strengthening effect, due to high strain rates, was considered with the conclusion that as such effects only make a limited increase in the capacity of the slab and may be conservatively ignored. In conclusion, RC flat slab structures are capable of resisting progressive collapse after the loss of a column. This is primarily due to their ability to develop ALPs. However, while flexural damage is usually fairly minimal, progressive punching shear failure is a critical design condition as it may result in a complete collapse. Furthermore, the inertial effects involved after a sudden removal can increase the damage sustained, although current design methods may be over conservative.
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Hobbs, Michael. "Effects of Slab-Column Interaction in Steel Moment Resisting Frames with Steel-Concrete Composite Floor Slabs." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2014. http://hdl.handle.net/10092/9946.
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Composite construction is widely used worldwide and is undergoing significant technological development. New Zealand is part of this development, with new beam options incorporating multiple unstiffened web openings and new deck profiles supported by extensive testing. However, one area where relatively little research has been undertaken is in the interaction of the composite slab with the seismic resisting system under lateral loading.
In order to provide important new information in this area, a series of full scale beam-column-joint-slab subassemblies were tested at the University of Canterbury. Specimens tested had moment end plate connections and different combinations of deck tray direction, and isolation of the slab from the column. An additional test uses a sliding-hinge type connection to assess the effect of the floor slab in this type of low damage connection.
In these tests the lateral capacity of the seismic resisting system was increased by up to 25% due to the presence of the slab in contact with the column. The increase in capacity is 10% greater for decking running in longitudinal direction than in the transverse direction as a result of a more substantial full depth slab bearing on the column. The floor slabs of the subassemblies with the slab cast against the column all showed a higher level of damage than for those with the isolated column and the post ultimate strength degradation of the subassemblies without special detailing was significant. The subassembly with a section of full depth slab surrounding the column also exhibited a higher capacity but with an improved post ultimate strength degradation. All moment end plate subassemblies sustained drifts of up to 5% without significant strength loss.
The sliding hinge joint showed little signs of damage under testing to 5% drift. Some inelastic deformation of the connection and beams was noted above 5% drift.
Results from both testing and numerical modelling have shown that the current methods used to design these systems are conservative but within 15% of the values observed. Further testing and modelling will be necessary before any meaningful changes can be made to the way in which these systems are designed. Recommendations have been made regarding the placements of shear studs in plastic hinge zones and the provision of slab isolation around beam-column connections.
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Kabir, Ahsanul. "Nonlinear analysis of reinforced concrete structural slabs." Thesis, University of Strathclyde, 1986. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21467.
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Nonlinear response of a structure to progressive loading may originate from two different sources viz, geometric nonlinearity and material nonlinear behaviour. For a rationally proportioned concrete structure, the material nonlinear responses are believed to contribute the major part of its total nonlinear behaviour. Geometric nonlinearities, become significant only when the structure is relatively slender. It is the material nonlinearities of reinforced concrete structures that are of interest in this investigation. Two plate bending finite elements have been generalised to include coupling of inplane actions with the bending effects. This was achieved through layering concept. One of these elements had been employed by some previous researchers. But the present formulation is different from theirs in that a numerical integration scheme is introduced to evaluate the stiffnesses and internal equivalent forces. A number of schemes for solving the nonlinear equations have been included in the present formulation. Suitability and effectiveness of these schemes in tracing the material nonlinear responses of concrete slabs have been examined. The numerical material model behaviour is based on the experimental observation reported by various authors. Readily available material characteristic properties are used in the description of the model. The overall response of reinforced concrete slabs is found to be significantly influenced by the cracking and post cracking treatment of concrete. Some form of tension stiffening scheme seems necessary to represent the structural response realistically. A number of conventional tension stiffening schemes have been incorporated, including a simple alternative formulation. The effect of different tension stiffening schemes and some other numerical parameters on the numerical solution of concrete structures have been investigated. Laboratory tests were carried out on a number of square and rectangular model slabs. The supporting arrangement and the applied loading systems were the main variables. These experimental records were later compared with the numerical predictions. Some other test results from literature have been included also.
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Deaton, James B. "A Finite Element Approach to Reinforced Concrete Slab Design." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7188.
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The objective of this study was the development of a procedure in GT STRUDL to design reinforced concrete flat plate systems based on the results of finite element analysis.
The current state-of-practice of reinforced concrete flat plate design was reviewed, including the ACI direct design and equivalent frame techniques, the yield line method, and the strip design method. The principles of these methods along with a critical evaluation of their applicability and limitations were presented as motivation for a finite element based design procedure. Additionally, the current state-of-the-art of flat plate design based on finite element results was presented, along with various flat plate modeling techniques. Design methodologies studied included the Wood and Armer approach, based on element stress resultants, and the resultant force approach, based on element forces.
A flat plate design procedure based on the element force approach was embodied in the DESIGN SLAB command, which was implemented in GT STRUDL. The DESIGN SLAB command provides the user the ability to design a slab section by specifying a cut definition and several optional design parameters. The procedure determines all nodes and elements along the cut, computes the resultant moment design envelope acting on the cross-section, and designs the slab for flexure in accordance with provisions of ACI 318-02.
Design examples presented include single-panel flat plate systems with various support conditions as well as multi-panel systems with regular and irregular column spacing. These examples allowed for critical comparison with results from experimental studies and currently applied design methods in order to determine the applicability of the implemented procedure. The DESIGN SLAB command was shown to produce design moments in agreement with experimental data as well as conventional design techniques for regular configurations. The examples additionally showed that when cuts were not oriented orthogonally to the directions of principle bending, resulting designs based on element forces could significantly under-reinforce the cross-section due to significant torsional effects.
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Lodi, Sarosh Hashmat. "Reinforced concrete slab elements under bending and twisting moments." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/1192.
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Gao, Zhicheng. "Corrosion Damage of Reinforcement Embedded in Reinforced Concrete Slab." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1478174479305336.
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Boting, Antony John. "Modelling of reinforced concrete slab deflections at service loading." Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/8458.
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Includes bibliographical references.Deflection under service loading is an important aspect of reinforced concrete slab design. Under-design can cause large deflections which can be expensive to repair, if at all possible. Over-design can lead to material wastage and unnecessary dead load. Deflection is inversely proportional to the effective moment of inertia of the section under consideration. Cracks, which may or may not be present at the serviceability limit state, have a profound effect on the moment of inertia. Many Codes of practice approach the calculation of deflection in a conservative manner by using the cracked moment of inertia in deflection calculations and ignoring the effect of the concrete in tension. Two of the Codes reviewed make an attempt at including the stiffening effect of the concrete in tension. The theory in the CEB/FIP Model Code is used as a basis for the method that is developed to predict maximum deflections. This method proposes that the total maximum deflection is composed of two components: an elastic deflection and a deflection due to cracking. The elastic deflection for a beam is determined from elastic formulae that are developed from first principles for standard beam cases. The deflection due to cracking involves the cracking moment capacity of the beam, what portion of the beam is cracked, the formation of a hinge and the rotation of this hinge. One-way spanning slabs can be treated as broad, shallow-beams. Two-way spanning slabs are more complicated and to determine the load dispersion of a uniformly distributed load on such a slab, it is divided into five sets of orthogonal strips. The two outer strips do not carry any load. The three inner strips intersect at nine points or nodes. The deflection of each pair of orthogonal strips at each of the nine nodes must be equal. Deflection equations are set up in terms of an unknown portion of the load at each node. Since the full load at each node is known, the sum of the loads in the orthogonal directions must be equal to this full load. A matrix is set up and solved and the load dispersion at each node is determined. The equivalent load on a strip spanning through the region of maximum deflection is thus found. For the two orthogonal strips spanning through the region of maximum deflection, the average deflection is then taken. A computer program is written which incorporates the above approach. The program is then run for slab configurations that were tested in the laboratory and the results are compared. The results show that the proposed computational models over-predict slab deflections. As soon as the slab is clamped on more than one edge or if the aspect ratio increases above 1 then the results in the orthogonal directions differ by a large amount. The recommended improvements to these computational models are: - Increase the number of orthogonal strips and introduce torsion. This will also improve the continuity between strips spanning in the same direction. The tension stiffening factor has to be redefined. This will reduce the contribution of deflection due to cracking.
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Alzlfawi, Abdullah Hamoud. "EFFECT OF SLAB AND PIER CONNECTION ON TRANSVERSE CRACKING IN STRUCTURAL SLAB BRIDGES." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1525450625325638.
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Zioris, Stavros, and Alija Vranjkovina. "Evaluation of a Tramway’s Track Slab in Conventionally Reinforced Concrete or Steel Fibre Concrete." Thesis, KTH, Betongbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177890.
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The dominant reinforcement used widely for concrete structures is conventional steel bars (rebars). Nevertheless, the perpetual effort toward evolution and development could not exclude the engineering field, thus new innovative and sophisticated methods are introduced. It is true that, due to lack of extended regulations and standards, the fibre reinforced concrete (FRC) was limited to non-structural applications. However, the last years the situation is changing rapidly and already the applications of FRC include actual structural members. The subject of the current thesis was a tramway’s track slab from “Sparvag City” project in Stockholm. The aim was to evaluate the track slab, in terms of alternative reinforcing ways. In particular three models were examined; model I – conventional reinforcement, model II – steel fibre reinforced concrete (SFRC) and model III – SFRC with conventional reinforcement. The assessment was performed from structural, regulations – compliance, economic and ergonomic perspective. A static linear analysis of the track slab was performed using Abaqus; a finite element analysis (FEA) software. The track slab was subjected only to mechanical loads (selfweight and traffic actions) and thus, the design internal forces were extracted. Thereafter, Eurocode 2 (EN 1992-1-1, 2004) and Swedish standards for FRC structures (SS 812310:2014) were utilized for the reinforcement design of the models. The design was performed in ultimate limit state (ULS), for bending moment and shear resistance, and in serviceability limit state (SLS), for stress limitation and crack control. Model I and III were successfully designed abiding with the respective regulations and requirements, while “only fibres” model was considered valid only for bending moment resistance according to SS 812310:2014. Consequently only models I and III were compared with each other. From the economic comparison it was obtained that model I was less expensive than model III, but on the other hand its construction time was larger. Furthermore model III contained significantly less total rebars’ mass in comparison to model I. This particularity was crucial for the ergonomic assessment. The human factors, that were relevant to the ergonomic assessment, improved the quality of the comparison and the extracted inferences, but also introduced aspects impossible to be put against economic facts as an equal quantity. Thus, there was not a final proposal as the best solution for the thesis subject.Armeringen av betongkonstruktioner domineras av konventionell armering (armeringsjärn). Med den ständiga strävan mot utveckling och förbättring har inom teknikområdet nya innovativa och avancerade metoder introducerats. Det är på grund av bristen på normer, standarder som fiberarmerad betong begränsats till icke- bärande ändamål. Däremot har situationen förändrats under de senaste åren, redan idag kan man se konstruktioner där fiberarmering används till bärande ändamål. Amnet for den aktuella masterexamen var betongplatta i projektet ”Sparvag City” i Stockholm. Syftet var att utvärdera betongplattan, i form av att undersöka alternativa armeringsmöjligheter. I synnerhet undersöktes tre modeller; modell I- konventionellt armerad platta, modell IIstålfiberarmerad platta och modell III stålfiberarmerad platta kombinerad med konventionell armering. Modellernas möjligheter att uppfylla regelverkens krav undersöktes, men de jämfördes även ur ekonomiskt samt ergonomiskt perspektiv. En statisk linjär analys av betongplattan genomfördes i ett finit element program, Abaqus. Betongplattan utsattes för mekanisk belastning (egenvikt samt trafiklast) för vilken dimensionerande krafter extraherats. Därefter användes Eurocode 2 (EN 1992-1-1, 2004) och den svenska standarden för fiberarmerade betong konstruktioner (SS 812310:2014) för vidare konstruktionsberäkningar. Konstruktionsberäkningarna för betongplattan genomfördes i brottgränstillstånd för böjmoment samt tvärkraft, i brukgränsmotståndet undersöktes betongplattan för spänningsbegränsningar samt sprickkontroll. Konstruktionsberäkningarna kunde genomföras för modell I och III med de existerande föreskrifterna och kraven, men modellen med ”endast fibrer” kunde endast dimensionerna för böjmoment enligt SS 812310:2014. Därför kunde endast modell I och III fortsättningsvis jämföras med varandra. Från den ekonomiska jämförelsen erhölls det att modellen I var billigare än modell III, men att konstruktionstiden var längre. Dessutom var behoven för konventionell armering (armeringsjärn) betydligt mindre för modell III till skillnad från modell I. Modellernas innehåll av konventionell armering var avgörande för den ergonomiska bedömningen. Den mänskliga faktorn, som var relevanta för den ergonomiska bedömningens, gav jämförelsen av modellerna en annan dimension, där de viktiga mänskliga faktorerna
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Manatakos, Kyriakos. "Behaviour and design of reinforced concrete core-slab-frame structures." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ30330.pdf.
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Koch, Pierre-Alexandre. "Seismic response of high-strength concrete beam-column-slab specimens." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0030/MQ50632.pdf.
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Haglund, Johanna. "Heatloss through a concrete slab - a comparison of edge beams." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-93608.
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Of all the heat that is supplied in an average house in Sweden, about 15% of the heat leaks out through the foundation and the ground. A foundations task is to provide a solid base for a house while it should also keep the heat in the house. This report deals with the foundation concrete slab, where the focus is largely on comparing three different types of edge beams with respect to thermal bridges and energy consumption. This work has been performed in collaboration with Fiskarhedenvillan which is one of the largest house suppliers in Sweden. Fiskarhedenvillan are constantly working with reducing the energy consumption in their houses and now wish to obtain a better insight into how the choice of edge elements in the slab can affect this. To get a better understanding of how heat transfer works the report begins with a theoretical part. It deals with how heat conduction, radiation and convection works. The theoretical part also deals with foundations, thermal bridges, concrete slab and edge beams in general. The edge beam solutions mentioned in the report are: • U‐min grund, energy‐efficient • Leca edge element • Dorocell, L‐element Using the computer program HEAT2, a simulation of the edge beams has been made to obtain different values of thermal bridges. These values were then used to calculate how the choices of the edge beams affect the total energy consumption in a houseAv den värme som tillförs i en genomsnittlig villa i Sverige försvinner cirka 15 % av värmen ut genom grunden och ner i marken. Grundkonstruktionens uppgift är bland annat att utgöra ett stadigt underlag för huset samtidigt som den ska hålla kvar värmen i huset. Detta examensarbete behandlar grundkonstruktionen platta på mark där fokus främst ligger på att jämföra tre olika typer av kantbalkar med avseende på köldbryggor och energiförbrukning. Arbetet har utförts i samarbete med Fiskarhedenvillan som är en av Sveriges största husleverantörer. Fiskarhedenvillan jobbar ständigt med att minska energiförbrukningen hos deras villor och önskar nu att få en bättre inblick i hur valet av kantelement vid platta på mark kan påverka detta. För att få en bättre förståelse för hur värmetransport fungerar börjar rapporten med en teoretisk del. Där behandlas hur värmeledning, strålning och konvektion fungerar. Den teoretiska delen tar även upp grundläggning, köldbryggor, platta på mark och kantbalkar i allmänhet. De kantbalkslösningar som behandlas i rapporten är: U‐min grund energieffektiv Leca kantelement Dorocell, L‐element Med hjälp av dataprogrammet HEAT2 har en simulering av kantbalkarna gjorts för att få fram olika värden på köldbryggor. Dessa värden har sedan använts för att få fram hur den totala energiförbrukningen i en villa påverkas av de olika kantbalkarna.
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Koch, Pierre-Alexandre. "Seismic response of high-strength concrete beam-column-slab specimens." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21308.
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The effects of high-strength concrete on the seismic performance of reinforced concrete exterior beam-column-slab subassemblages were investigated by comparing the behaviour of three full-scale specimens. Two specimens, one constructed with normal-strength concrete and one constructed with high-strength concrete, were designed with square columns. The specimen tested in this thesis was constructed with high-strength concrete and designed with a circular column. All the specimens were designed as ductile moment-resisting frames and tested under reversed-cyclic loading.The Canadian Standard, CSA A23.3-94, limits the concrete compressive strength used in seismic design to 55 MPa. The applicability of the current design specifications, developed for normal-strength concrete, were investigated when applied to ductile beam-column joints made with higher strength concrete. The reduced amount of confinement reinforcement permitted by the New Zealand Standard is also investigated. All specimens in the study were instrumented to allow for detailed strain, load and deflection measurements to be monitored during testing process. The hysteretic behaviour of each specimen was analysed in order to investigate energy dissipating characteristics as well as attainable ductility levels. Strains in the slab bars were used to determine the amount of effective slab reinforcement which contributes to the negative flexural capacity of the main beam. Deflection and strain measurements were used to determine the full torsional response of the spandrel beams. Non-linear dynamic analyses were also performed to compare the predicted seismic performance of normal-strength concrete and high-strength concrete prototype structures.
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Manatakos, Kyriakos 1960. "Behaviour and design of reinforced concrete core-slab-frame structures." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=42088.
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This dissertation examines the response and design of reinforced concrete core-slab-frame structures subjected to monotonically increasing earthquake and gravity loads throughout the entire load range until failure, presenting findings from three separate studies by Manatakos and Mirza (1995) continuing the M. Eng. thesis research by Manatakos (1989). A typical building is selected consisting of a central core substructure composed of elevator, staircase and infilled slab cores, with coupling and lintel beams, and surrounding slabs joining to a frame substructure composed of slab-band girders, slabs and columns.Stage 1 concentrates on the elastic response and Stage 3 examines the nonlinear response of the core-slab-frame structure considering the effects of cracking and crushing of concrete, strain-hardening of the reinforcement, and tension-stiffening. Analyses involve three-dimensional elastic and nonlinear finite element modeling techniques of the structure to investigate the contribution and influence of the various structural components. The structural response is examined for the deformations, the concentrated reinforcement strains and concrete stresses in the cores, the force and stress distributions in the structural members, and the failure mode.
Stage 2 focuses on the design and detailing of the core-slab-frame structure following seismic provisions of building code requirements for reinforced concrete structures where applicable as given in the CSA Standard CAN3-A23.3-MS4 (1984), the ACI Standard ACI 318M-83 (1983) and the New Zealand Standard NZS3101 (1982). Assumptions made in the conventional design procedures and any shortcomings encountered are examined. Suitable design procedures and reinforcement details are suggested where no provisions exist in the codes.
Findings demonstrate complex three-dimensional interaction among the cores, beams, slabs and frames in resisting the lateral and gravity loads, and show considerable strength, ductility and energy absorption capability of the structure. Critical areas for design include the joints and junctions near the vicinity of core wall-slab-beams ends and corners. Plastic hinging extends over the lower 2.5% to 33% height of the structure with the majority of inelastic action and damage concentrated in the bottom 10% to 15% height, predicting an ultimate load of 3.4 to 5.9 times the design earthquake load with top drifts of the structure between 750 mm to 1375 mm.
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Zou, Yunyi. "FRP Reinforced Concrete and Its Application in Bridge Slab Design." Case Western Reserve University School of Graduate Studies / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=case1101960743.
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Mattsson, Johan, and Fredrik Åman. "Cracking in a slender concrete slab due to thermal variation." Thesis, KTH, Betongbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259932.
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Concrete slabs used in thepulp and paper industries are often situated outdoors, which means that theslabs are exposed to temperature variations due to different weatherconditions. These temperature variations together with operational temperaturesassociated with the manufacturing process, may introduce high temperaturegradients in the concrete. It is believed that the combination of these thermalloads have resulted in cracking in a slender concrete slab.The aim of this degree project has been to determine if the combination ofseasonal temperature and operational temperature is sufficient to introduce thetype of cracking seen in-situ in the concrete slab of a factory in Sundsvall,400 km north of Stockholm. This was achieved by simulating the development ofcracks in a slender concrete slab exposed to thermal loads using finite elementanalysis (FEA). In order to determine the accuracy of the model, the resultswere compared and evaluated against a crack mapping produced by Sweco. Furthersimulations were also carried out, in order to investigate if continuedcracking would occur beyond the time span of the Sweco investigation.The material model Concrete damage plasticity (CDP) in BRIGADE/Plus and Abaquswas used to predict the crack pattern and crack width in the concrete slab.Linear-elastic and non-linear material properties were used in the modelling ofthe concrete slab. The linear-elastic model indicated that thermal variationshowed significant risk of cracking. Thereafter, non-linear material propertieswere used in the modelling process. The cracking was simulated using ambienttemperature data and operational temperatures from the production plant.The results showed that cracking started when thermal loads were introduced tothe model. The ambient seasonal temperature alone was not enough to introducethe type of cracking seen in-situ on the slab. The combination of seasonalambient temperature and operational temperature was needed, in order for cracksto develop in the concrete slab. The results also indicated that the crackswill propagate further, but this can only be confirmed by performing additionalcrack mapping on site.Betonggrunder som används för utrustning inom massa- och pappersindustrin befinner sig ofta utomhus vilket betyder att dessa är utsatta för vädrets förändringar. Temperaturvariationer i omgivningen och temperaturer som kommer från tillverkningsprocesserna kan medföra att höga temperaturgradienter skapas i betongen. Det är troligt att kombinationen av dessa termiska belastningar har gett upphov till sprick-bildning i en betonggrund.Målet för detta examensarbete har varit att bestämma, om huruvida kombinationen av års- temperaturer och temperaturer från industriprocessen är tillräckligt för att skapa den typ av sprickbildning i betonggrunden som iaktagits på plats hos en fabrik i Sundsvall. Det gjordes genom simulering av sprickbildning på betonggrunden, där grunden utsattes för termiska belastningar genom att använda finita element analys (FEA). För att bestämma tillförlitligheten hos metoden jämfördes och utvärderades resultatet mot en sprickkartering utförd av Sweco baserad på observationer ute på fabriken. Vidare gjordes ytterligare simuleringar utöver det tidsspann som Swecoundersökningarna visade, detta för att undersöka om huruvida sprickningen skulle fortgå.Materialmodellen Concrete damage plasticity (CDP) som finns i programmen BRIGADE/Plus och Abaqus användes för att förutse sprickbildning och sprickbredd i betonggrunden. Linjärelastiska och icke-linjära materialparametrar användes i modelleringen av betonggrunden. Utetemperatursdata tillsammans med temperaturer från industriprocessen användes för att undersöka anledningen till sprickbildningen.Resultaten av analyserna visade att sprickbildning uppkom när betonggrunden ut-sattes för termiska laster. Temperaturer från omgivningen var inte tillräckligt för att initiera sprickbildning. Kombinationen av temperaturer från omgivningen och industriprocessen behövdes för att sprickbildning skulle ske. Resultaten visade även att sprickbildningen kan fortsätta, med fler och bredare sprickor som följd.För att förhindra att sprickor uppstår i framtiden är det väsentligt att betona vikten av att minska uppkomsten av stora temperaturgradienter i betonggrunden.
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El-Hafez, L. M. A. "Direct design of reinforced concrete skew slabs." Thesis, University of Glasgow, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383130.
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Saad, Ahmad. "Material properties of concrete used in skewed concrete bridges." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-54412.
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This thesis has discussed both properties and geometry of concrete slabs used in bridges. It gave understanding on behavior of concrete in both tension and compression zones and how crack propagates in specimens by presenting both theory of fracture and performing concrete tests like tension splitting, uniaxial compression and uniaxial tension tests. Furthermore, it supported experimental tests with finite elements modelling for each test, and illustrated both boundary conditions and loads. The thesis has used ARAMIS cameras to observe crack propagations in all experimental tests, and its first study at LNU that emphasized on Brazilian test, because of importance of this test to describe both crushing and cracking behavior of concrete under loading. It’s an excellent opportunity to understand how concrete and steel behave individually and in combination with each other, and to understand fracture process zone, and this has been discussed in theory chapter. The geometry change that could affect stresses distributions has also described in literature and modelled to give good idea on how to model slabs in different angles in the methodology chapter. Thus, thesis will use finite elements program (Abaqus) to model both experimental specimens and concrete slabs without reinforcement to emphasize on concrete behavior and skewness effect. This means studying both properties of concrete and geometry of concrete slabs. This thesis has expanded experimental tests and chose bridges as an application.
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Ismail, Eman. "Distribution of stresses and displacements in skewed concrete slabs." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-66839.
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A 3D nonlinear finite element analysis was developed for simulating the behavior of skewed concrete slabs and to identify the response of the slab with different angles and element sizes. The purpose of this research is helping the engineering and construction industry to utilize the FEM study and results more in different structural applications.Simulations performed in ABAQUS for skewed slabs are also compared to straight and skewed slabs according to the analytical formulation by Timoshenko.The result showed that when the distance increases, the load capacity measured by reaction forces decreases for all different skew angles except angle 0° and 15° which show a stable reaction force along the entire path. .The study reveals that depending on the skew angle and the element size, the stress distribution and vertical displacements in the slab vary significantly from those in a straight slab. It is shown that the displacement decreases with the increase of the skew angle while the stresses increase with the decrease of the skew angle.There are small differences in the vertical displacements and stress distribution between the results obtained by this study and the results obtained by Timoshenko regarding the plates with skews of 0°, 30° and 45°.
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Hon, Alan 1976. "Compressive membrane action in reinforced concrete beam-and-slab bridge decks." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/5629.
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Bai, Jong-Wha. "Seismic fragility and retrofitting for a reinforced concrete flat-slab structure." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/521.
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The effectiveness of seismic retrofitting applied to enhance seismic performance was assessed for a five-story reinforced concrete (RC) flat-slab building structure in the central United States. In addition to this, an assessment of seismic fragility that relates the probability of exceeding a performance level to the earthquake intensity was conducted. The response of the structure was predicted using nonlinear static and dynamic analyses with synthetic ground motion records for the central U.S. region. In addition, two analytical approaches for nonlinear response analysis were compared. FEMA 356 (ASCE 2000) criteria were used to evaluate the seismic performance of the case study building. Two approaches of FEMA 356 were used for seismic evaluation: global-level and member-level using three performance levels (Immediate Occupancy, Life Safety and Collapse Prevention). In addition to these limit states, punching shear drift limits were also considered to establish an upper bound drift capacity limit for collapse prevention. Based on the seismic evaluation results, three possible retrofit techniques were applied to improve the seismic performance of the structure, including addition of shear walls, addition of RC column jackets, and confinement of the column plastic hinge zones using externally bonded steel plates. Finally, fragility relationships were developed for the existing and retrofitted structure using several performance levels. Fragility curves for the retrofitted structure were compared with those for the unretrofitted structure. For various performance levels to assess the fragility curves, FEMA global drift limits were compared with the drift limits based on the FEMA member-level criteria. In addition to this, performance levels which were based on additional quantitative limits were also considered and compared with FEMA drift limits.
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Hedebratt, Jerry. "Industrial Fibre Concrete Floors : Experiences and Tests on Pile-Supported Slab." Doctoral thesis, KTH, Bro- och stålbyggnad, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102670.
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Pile supported floor slabs have often been designed solely in ultimate limit state ULS and then foremost with uniformly distributed loadings UDL. The investigation of serviceability limit state SLS has been of simpler nature, even according to the governing codes of practice. Often it has been minimum‑reinforced with the presumption that full friction to the supporting ground is present, whit‑out any inspection, which by the Swedish code of practice even more reduced the addition of crack reinforcement. The cracks have not been controlled, before they in fact have occurred. For pile supported floor slabs the ground support will be there still, at least for a time, after the casting. As the ground settles, as dehydration always will occur, and drainage and the covering roof the precipitation to reach the ground, the slab will often be completely free bearing between the piles. The minimum reinforcement is based on the assumption that only the upper layer is needed to reinforce due to dehydration shrinkage – despite that the whole floor section in time will obtain the same moisture profile and also shrinkage magnitude. One often excludes the influence of creep and temperature and the affect from external loading and local variance of restraints in calculations in the SLS. Research on behaviour in SLS has been modest; in spite of that the contractors and the client and finally the end‑user of the floors often suffer from these problems. It has by this thesis been established that the shrinkage of the concrete used for industrial floors is large 0.9‑1.1 ‰, and that the problem foremost arise from cracking and problems with joints and unevenness in the floor. The integrated method for design and production of industrial floors is a way to the solution, but requires that all involved assign to co‑operate to 100 %. Furthermore it is required that one selects the proper materials to the proper design and the proper production method. If one will save cost this will often be on materials; which will lead to reduced reinforcement content and reduced concrete thickness. This way is wrong and will in end make the client suffer economically. A way to solve this has been to cast the floors with steel fibre concrete SFC; from the beginning often a little bit thicker and with moderate steel fibre content and complementary reinforcement, compared to present execution. The competition from abroad has nevertheless shaped solutions that with thinner slabs and less traditional reinforcement and invalid design calculations compete on faulty grounds. This work demonstrates how this make the floor suffer in ULS and SLS. Trough full‑scale testing (half of a normally loaded industrial floor in matter of geometry) where a pile supported floor slab has been simulated by a flat‑slab floor cast in steel fibre concrete, it has been shown that the solution with steel fibre concrete performs well in slabs for industrial floors. On one hand it gives the opportunity to production wise superior methods for placing concrete which potentially could gain the environment with reduced reinforcement content, and on the other hand SFC brings a ductile failure behaviour for loadings with much larger magnitudes than in normal ULS design, and further SFC provides with a stiffer response and with possibility to construct slabs with small creep deformation. Finally it has been established that, when it comes to short‑term point loadings (ULS) and with long-term point loadings (SLS) one can rely on the bearing capacity and the tough behaviour of SFC. And that one may exert an influence on both limit states, through variation of the SFC and the reinforcement content. This is shown for a real bearing structure, the pile supported industrial floor, and that in a safe way.QC 20120921
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Cheung, (Patrick) Pak Chiu. "Seismic design of reinforced concrete beam-column joints with floor slab." Thesis, University of Canterbury. Civil Engineering, 1991. http://hdl.handle.net/10092/9451.
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Beam-column joints are addressed in the context of current design procedures and performance criteria for reinforced concrete ductile frames subjected to large earthquake motions. Attention is drawn to the significant differences between the pertinent requirements of concrete design codes of New Zealand and the United States for such joints. The difference between codes stimulated researchers and structural engineers of the United States, New Zealand, Japan and China to undertake an international collaborative research project. The major investigators of the project selected issues and set guidelines for co-ordinated testing of joint specimens designed according to the codes of the countries. The tests conducted at the University of Canterbury, New Zealand, are reported. Three full-scale beam-column-slab joint assemblies were designed according to existing code requirements of NZS 3101:1982, representing an interior joint of a one-way frame, an interior joint of a two-way frame, and an exterior joint of a two-way frame. Quasistatic cyclic loading simulating severe earthquake actions was applied. The overall performance of each test assembly was found to be satisfactory in terms of stiffness, strength and ductility. The joint and column remained essentially undamaged while plastic hinges formed in the beams. The weak beam-strong column behaviour sought in the design, desirable in tall ductile frames designed for earthquake resistance, was therefore achieved. Using the laws of statics and test observations, the action and flow of forces from the slabs, beams and column to the joint cores are explored. The effects of bond performance and the seismic shear resistance of the joints, based on some postulated mechanisms, are examined. Implications of the test results on code specifications are discussed and design recomendations are made.
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Isabell, Eriksson, and Niklas Karlsson. "Non-Linear Assessment of a Concrete Bridge Slab Loaded to Failure." Thesis, KTH, Betongbyggnad, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-188900.
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This thesis covers an investigation regarding the failure in the bridge slab of Gruvvägsbron, which was the result of the full scale test that the bridge was subjected to prior to demolition. Using the non-linear finite element software ATENA 3D, a model of the bridge was assembled, with the purpose to attempt to reenact the test procedure and realistically capture the failure load and behaviour. This in order to be able to conclude what kind of failure that occurred. The initial part of this thesis presents a summary of a conducted literature study, which aims to give deeper knowledge regarding the linear shear and punching shear phenomena and their respective failure mechanisms, and how they are applied on bridge slabs. Furthermore, the shear capacity of the bridge was calculated according to current design codes. A parameter study was conducted on the model, which initially showed a over-stiff response. The aim of this was to study the influence of key variables on the outcome of the analysis, and hopefully get closer to the failure load acquired inthe experiment. From the studied parameters, it was observed that a combined reduction of the tensile strength and fracture energy, together with a low fixed crack coefficient had the largest influence on the outcome of the analysis. It was also observed that the location of the failure and failing load was dependant on how the loading was applied to the model, i.e. via load control or deformation control. The final model failed at a load which surpassed the actual failure load by 10.5%. The mode of failure obtained in all the analyses were the result of a large shear crack propagating from the edges of the loading plate, through the slab to the slab/girder-intersection. This indicates that the type of failure that occurred was primarily due to a linear shear mechanism with a secondary punching effect. The design values calculated by keeping with the current codes resulted in too conservative values when compared to the obtained failure load from the experiment. This proves the difficulty in regarding the internal force distribution in slab struc-tures as well as the shear carrying width, which from the analysis were found to be larger than that obtained from the code.Denna uppsats behandlar en utredning gällande brottet i plattan på Gruvvägsbron, som var resultatet av det fullskaletest som bron utsattes för innan rivning. Med hjälp av den icke-linjära finita element-programvaran ATENA 3D skapades en modell avbron, med syfte att på ett realistiskt sätt försöka återskapa experimentet och fånga brons verkliga beteende. Detta för att således kunna dra slutsatser angående brottets natur. Den första delen av denna uppsats innehåller en sammanfattning av en utförd litteraturstudie, som ämnar ge en ökad förståelse angående fenomenen skjuvning och genomstansning, tillsammans med olika brottmekanismer relaterade till dessa. Vidare har brons motstånd mot skjuv- och genomstansningbrott beräknats enligt rådande normer. En parameterstudie utfördes på modellen, då den ursprungligen uppvisade ett överstyvt beteende. Syftet med detta var att studera nyckelparametrars påverkan på analysens resultat, och eventuellt komma närmare den verkliga brottlasten i experimentet. Av de studerade parametrarna observerades att en samtida reduktion av draghållfasthet och brottenergi, samt ett lågt värde på den så kallade "fixedcrack"-koefficienten gav störst inverkan på resultatet. Vidare observerades att brottets lokalisering och brottlasten var beroende av hur lasten påfördes modellen, dvs genom last- eller deformationsstyrning. Den slutgiltiga modellen gick till brott vid en last som översteg den verkliga brottlasten med 10.5%. Brottet som skedde var i samtliga analyser resultatet av en skjuvspricka som sträckte sig från kanten av lastplattan, genom plattan, ner till mötet mellan platta och balk. Detta indikerar att den typ av brott som skedde var ett primärt skjuvbrott med en sekundär stanseffekt. Lastvärdena beräknade enligt rådande normer tycks vara för konservativa, om jämförelse görs med lasten som uppnåddes i experimentet. Detta visar på svårigheten i att bedöma den inre kraftspridningen i plattor, och även dess skjuvbärande bredd, då analysen visade att denna var betydligt större än vad som ges i koden.
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Park, Hae-geun. "MECHANICAL BEHAVIOR OF REINFORCED CONCRETE SLAB RETROFITTED WITH CARBON FIBER SHEET." Kyoto University, 2000. http://hdl.handle.net/2433/157080.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第8355号
工博第1920号
新制||工||1170(附属図書館)
UT51-2000-F259
京都大学大学院工学研究科土木システム工学専攻
(主査)教授 小野 紘一, 教授 田村 武, 教授 宮川 豊章
学位規則第4条第1項該当
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Eder, Martin A. "Inelastic behaviour of hybrid steel/concrete column-to-flat slab assemblages." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/7017.
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The use of tubular columns in conjunction with reinforced concrete flat slabs provides structurally efficient solutions which avoid undesirable failure modes such as those associated with shear. This thesis is concerned with the development of a tubular column-to- flat slab connection system that enables reliable performance under seismic loading conditions. During this research a novel detail which features a gap around the column is proposed and developed; hence only the structural steel shearhead establishes the connection. The exposed parts of the shear arms (fuses) are designed to yield prior to punching shear failure, in a way that utilises the favourable features of steel in terms of the response to seismically induced loads. The proposed connection could serve as a primary lateral resisting system within all building configurations in regions of low to moderate seismicity or as a secondary system in areas of signi cant seismicity. In order to provide validation for the proposed details as well as associated numerical and design procedures, a purpose-built rig which is suitable for large scale testing of structural sub assemblages under combined gravity and uniaxial lateral loading, has been designed and constructed, and subsequently employed for a number of tests. Test results and numerical analyses are presented with respect to a conventional con guration, as well as for the proposed, partially embedded connection. The latter is shown to offer enhanced ductility compared with traditional forms. The results are used to demonstrate the favourable inelastic performance of the proposed detail in terms of ductility, low degradation effects and increased energy dissipation capabilities. Complementary small scale slab panel tests are also used to further optimise the composite behaviour of the proposed detail. Additionally, a closed form solution based on plastic limit analysis which can serve as a basis for a simplified design approach is proposed. Finally, the main findings from the experimental and analytical investigations are highlighted, and recommendations for future research are outlined.
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Tarek, Asmaa, and Zhir Farhad. "Implementering av VBS system i Sverige." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-84294.
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Betong är idag ett av de material som vi använder mest i byggbranschen och det har sinaföljder. Mer än 50 % av energiutsläppen från byggplatsen kommer från cementtillverkningen.Voided biaxial slab eller VBS är en revolutionerande teknik där man gjuter in plastbollar ibetongen tillsammans med armeringen. Arbetstiden samt torktiden kortas ned samtidigt somvi bevarar hållfastheten och dess funktionalitet. I den här rapporten kommer vi titta närmarepå VBS teknik och jämföra det med konventionell betongplatta och se om tekniken är lämpligför att implementeras i Sverige.Vi har använt oss av en kvalitativ metod i form av källanalys från internet och tryckta källor.Även en komparativ metod i de fallen vi har hittat information från mer än en källa.Rapporten kommer enbart fokusera på betongplattor och våningsavskiljande bjälklag. VBSanvänds i horisontella plan endast. Tak och väggar är därför uteslutna. Tekniken kommerpresenteras i form av viktiga aspekter för dess överlevnad i den svenska marknaden såsomekonomi, strukturella fördelar och hållbarhet.Resultatet visar att VBS rent ekonomiskt nästan bara är positivt jämfört med denkonventionella betongplattan som endast består av armerad betong. Konstruktionsmässigt ärVBS ett konkurrenskraftigt alternativ till armerad betong. Böjhållfastheten är detsamma somarmerad betong. Andra bra positiva aspekter är miljövänligheten, arbetsmiljömässigt,energikonsumtion och värmeisolering.De mindre bra egenskaperna är sämre prestanda i skjuvmotstånd, brandmotstånd ochljudisolering.VBS kan implementeras i Sverige men för att plast ska introduceras i en så pass stor skala såbehövs en infrastruktur. Den bör tillgodose hållbart produktion av Bubbledeck och separeramaterialen vid rivning. Tekniken medför stora fördelar men trots det kan företagen få svårt attmotivera sig till att bygga med VBS när betong är så lättillgängligt och varit med så länge.Concrete is today one of the materials we use most in the construction industry and it has itsconsequences. More than 50% of the energy emissions from the construction site come fromcement production. Voided biaxial slab or VBS is a revolutionary technique in which plasticballs are cast into the concrete together with the reinforcement. The working time and thedrying time are reduced while maintaining the strength and its functionality. In this report, wewill take a closer look at VBS technology and compare it with conventional concrete slab andsee if the technology is suitable for implementation in Sweden.We have used a qualitative method in the form of source analysis from the Internet andprinted sources. Also a comparative method in cases where we have found information frommore than one source.The report will focus solely on concrete slabs and floor separating flooring. VBS is used inhorizontal planes only. Roofs and walls are therefore excluded. The technology will bepresented in the form of important aspects for its survival in the Swedish market such aseconomy, structural benefits and sustainability.The result shows that VBS is financially almost only positive compared to the conventionalconcrete slab, which consists only of reinforced concrete. In terms of design, VBS is acompetitive alternative to reinforced concrete. The flexural strength is the same as reinforcedconcrete. Other good positive aspects are environmental friendliness, work environment,energy consumption and heat insulation.The less good features are poor performance in shear resistance, fire resistance and soundinsulation.VBS can be implemented in Sweden but for plastic to be introduced on such a large scale, aninfrastructure is needed. It should meet the sustainable production of Bubbledeck and separatethe materials during demolition. The technology brings great benefits, but despite this,companies can find it difficult to motivate them to build with VBS when concrete is so easilyaccessible and has been around for so long.
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AlHarras, Omar. "Seismic behaviour and nonlinear modeling of reinforced concrete flat slab-column connections." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54469.
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The contemporary structural design practice of tall buildings typically incorporates a lateral force resisting system, along with a gravity system that often includes reinforced concrete flat slabs. A major challenge with the design of this system is ensuring adequate strength and deformation capacities of the flat slab-column connections, especially when the structure is prone to strong seismic excitations. When a flat slab-column connection is subjected to a combination of gravity and lateral loads, failure may occur in multiple modes. Comprehensive literature reviews of the experimental studies and the analytical models related to reinforced concrete flat slabs, and flat slab-column connections are presented in Chapters 2 and 3, respectively.
The existing nonlinear models that are currently available in literature were developed as assessment tools for old flat-plate structures. Thus, they are not capable of capturing the hysteretic behaviour of ductile flat slab-column connections with shear reinforcement. In Chapter 4, a new nonlinear model for flat slab-column connections is proposed. Utilizing the proposed model allows detecting potential failures due to all the possible modes of failure. The model was verified and calibrated using data from actual experimental studies.
Chapter 5 investigates the effects of flat slabs on the global seismic response of typical high-rise concrete shear wall buildings. Two analytical case studies were conducted using a prototype building designed in Vancouver, Canada. The results from nonlinear dynamic analyses confirmed that including flat slabs in the analysis models of tall buildings is important to obtain accurate estimates of the structural responses and seismic demands. A concise summary of the research outcomes is presented in Chapter 6.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Sharifi, Haki. "Strength of edge column-slab connections of post-tensioned concrete flat plates." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0010/MQ32558.pdf.
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McHarg, Peter J. "Effect of fibre-reinforced concrete on the performance of slab-column specimens." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37272.pdf.
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Ghannoum, Carla M. "Effect of high-strength concrete on the performance of slab-column specimens." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0027/MQ50609.pdf.
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Ghannoum, Carla M. "Effect of high-strength concrete on the performance of slab-column specimens." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21294.
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The behaviour of interior slab-column connections in flat plates is investigated. The first part of this thesis discusses six two-way slab-column specimens which were designed such that they would fail in punching shear. The parameters investigated were the use of high-strength concrete and the concentration of the slab flexural reinforcement in the immediate column region. The effects of these parameters on the punching shear capacity, negative moment cracking, and stiffness of the two-way slab specimens are investigated.The second part of this thesis is a comparison of the test results obtained from this experimental program with the punching shear predictions of the Canadian CSA A23 3-94 Standard and the American ACI 318-95 Code. Some comparisons of the punching shear strength provisions of the British BS 8110-85 Standard and the European CEB-FIP 1990 Model Code are also carried out. Furthermore, the CSA Standard and the ACI Code predictions are compared to the experimental results obtained from some slab-column connections tested in this experimental program and tested by various investigators.
The beneficial effects of the use of high-strength concrete and of the concentration of flexural reinforcement in the immediate column vicinity are demonstrated. It is also concluded that the punching shear strength of slab-column connections is a function of the flexural reinforcement ratio and that the shear design of slabs according to the current Canadian and American codes can be unconservative under certain conditions. It is recommended that the punching shear expressions of the CSA Standard and the ACI Code be modified to include the effect that the flexural reinforcement ratio has on the shear capacity of slab structures.
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Stewart, Michael Andrew. "Sound transmission through a chipboard floating floor supported on a concrete slab." Thesis, Heriot-Watt University, 1996. http://hdl.handle.net/10399/718.
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Joyce, Patrick Conor. "Development of Improved Connection Details for Voided Slab Bridges." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/49108.
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Adjacent voided slab bridges (AVSB) are economical systems for short spans. They provide the advantages of having low clearances due to their small section depths, accelerated construction times, and high torsional stiffness. The current longitudinal connection detail, a partial depth grouted shear key, has been known to fail in many of these bridges. The failure leads to reflective cracking in the wearing surface which allows chloride laden water to seep
down through the joint, where it corrodes the reinforcement and prestressing strand. Ultimately, the failed keys lead to costly repairs and bridge replacements sooner than their proposed lifespan. This research project aimed to develop a more durable longitudinal connection detail by using sub-assemblages to test five alternate connections. The objective was to find a connection that abated all cracking in the shear key, thus removing the need for transverse post-tensioning. The tested connections employed alternate connection shapes and two different mix designs of fiber reinforced high strength concretes. The results showed that each tested connection outperformed the current detail. The findings of this research indicate that the longitudinal connection detail of adjacent member voided slab bridges should be modified. The modified version should be a blockout with lap splice connection detail utilizing a nonproprietary fiber reinforced high strength
concrete.Master of Science
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Ho, S. L. "An investigation into the behaviour of hollow ribbed (waffle) rectangular reinforced concrete slabs at ultimate limit state." Thesis, University of Abertay Dundee, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234752.
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Boltz, Daniel Edward. "Early performance of concrete pavement containing ground granulated blast furnace slag." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176839817.
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De, Vittorio Stefano. "Time-dependent behaviour of reinforced concrete slabs." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3247/.
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In this thesis is studied the long-term behaviour of steel reinforced slabs paying particular attention to the effects due to shrinkage and creep. Despite the universal popularity of using this kind of slabs for simply construction floors, the major world codes focus their attention in a design based on the ultimate limit state, restraining the exercise limit state to a simply verification after the design. For Australia, on the contrary, this is not true. In fact, since this country is not subjected to seismic effects, the main concern is related to the long-term behaviour of the structure.
Even if there are a lot of studies about long-term effects of shrinkage and creep, up to date, there are not so many studies concerning the behaviour of slabs with a cracked cross section and how shrinkage and creep influence it. For this reason, a series of ten full scale reinforced slabs was prepared and monitored under laboratory conditions to investigate this behaviour. A wide range of situations is studied in order to cover as many cases as possible, as for example the use of a fog room able to reproduce an environment of 100% humidity.
The results show how there is a huge difference in terms of deflections between the case of slabs which are subjected to both shrinkage and creep effects soon after the partial cracking of the cross section, and the case of slabs which have already experienced shrinkage effects for several weeks, when the section has not still cracked, and creep effects only after the cracking.
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Midkiff, Corey J. "Plastic voided slab systems: applications and design." Kansas State University, 2013. http://hdl.handle.net/2097/16874.
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Master of ScienceDepartment of Architectural Engineering
Kimberly Waggle Kramer
Reinforced concrete slabs are one of the most common components in modern building construction. Reinforced concrete slabs with plastic voids slabs are a new and innovative type of structural, concrete slab system developed to allow for lighter self-weight of the structure while maintaining similar load carrying capacity of a solid slab. Plastic voided slabs are capable of reducing the amount of concrete necessary to construct a building by 30 percent or more. This reduction can be beneficial in terms of financial savings as well as building performance. This report examines a two-way, reinforced concrete slab with plastic voids construction in comparison to traditional flat plate reinforced concrete slab construction. The design process for plastic voided slabs is directly compared with traditional two-way flat plate reinforced concrete slabs through a design comparison of typical bays of 20’ by 20’ (6m by 6m), 25’ by 25’ (7.6m by 7.6m), 30’ by 30’ (9m by 9m) and 35’ by 35’ (10.7m by 10.7m). The traditional slab design process follows the ACI 318-11 Building Code Requirements for Structural Concrete chapter 13 Direct Design Method, while the plastic voided slab design process is modified from the BubbleDeck Design Guide for compliance with BCA using AS3600 and EC2. Sizes of traditional slab bays are compared to sizes of plastic voided slab bays. Results of the comparison study are presented.
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Eriksson, Alexander, and Veronica Flykt. "Concrete floor : Design of prefabricated pre-stressed hollow core slabs with verification through PRE-Stress and comparison with site-cast slab." Thesis, KTH, Byggteknik och design, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279158.
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The most common prefabricated concrete slabs are hollow core slabs, which are usually pre-tensioned. How to design these parts is not compiled today in a manual where it is clear how this is done, this knowledge is generally classified as expert knowledge. The purpose was to bring forth how to design prefabricated pre-stressed hollow core slabs, HD/F, and then create a design aid that is compared by hand calculations with the PRE-Stress design program from StruSoft. Furthermore, to compare it with site-cast concrete slabs to see differences in the amount of material and the thickness of the structure under the same conditions.The design aid is not complete as some limitations had to be made. When it comes to results, the hand calculations in comparison with PRE-Stress have not resulted in identical answers but have proven to be on the safe side consistently through the design, which indicates that the design aid is fully functional. In the comparison with site-cast concrete slabs, it can be noted that prestressed hollow core slabs require less concrete volume, slimmer construction, and longer span widths but greater reinforcement volume.Det vanligaste prefabricerade betongbjälklaget är håldäcksplattor som oftast är spännarmerade. Hur man dimensionerar dessa bärverksdelar finns idag inte samlat i en handbok där det står tydligt hur man gör, den kunskapen klassas generellt som expertiskunskap. Syftet var att ta fram hur man dimensionerar prefabricerade förspända håldäcksplattor, HD/F, och sedan skapa ett dimensioneringshjälpmedel som jämförs genom handberäkningar med PRE-Stress dimensioneringsprogram från StruSoft. Vidare genomfördes jämförande beräkningar för platsgjutet betongbjälklag för att se skillnader i materialmängd och konstruktionstjocklek under samma förutsättningar.Dimensioneringshjälpmedlet är inte komplett då vissa avgränsningar behövts göras. När det kommer till resultat har handberäkningar i jämförelse med PRE-Stress inte resulterat i identiska svar, men visat sig hamna på säkra sidan konsekvent genom dimensioneringen vilket tyder på att dimensioneringshjälpmedlet är fullt användbart. I jämförelsen med platsgjutet bjälklag kan man konstatera att förspända håldäcksplattor ger mindre betongvolym, slankare konstruktion och längre spännvidder men större armeringsmängd.
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Sheedy, Patrick. "Alleviating concrete placement issues due to congestion of reinforcement in post-tensioned haunch-slab bridges." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/13251.
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Master of ScienceDepartment of Civil Engineering
Robert Peterman
A flowable hybrid concrete mix with a spread of 17 to 20 inches was created with a superplasticizer to be used in post-tension haunch-slab (PTHS) bridges where rebar congestion is heaviest. The mix would allow for proper concrete consolidation. A conventional concrete mix with a slump of three to four inches was also created to be placed on top of the hybrid mix. The conventional mix would be used to create a sloping surface on the top of the concrete. The two mixes could be combined in the PTHS bridge deck and act as one monolithic specimen. Standard concrete tests such as compressive strength, tensile strength, modulus of elasticity, permeability, freeze/thaw resistance, and coefficient of thermal expansion were determined for the mixes and compared. Core blocks were cast using both mixes and composite cores were drilled. The cores were tested and their composite split-tensile strengths were compared to the split-tensile strengths of cylinders made from the respective mixes. A third concrete mix was made by increasing the superplasticizer dosage in the hybrid concrete mix to create a self-consolidating concrete (SCC) mix with a 24-inch spread. The SCC mix was created as a worst-case scenario and used in the determination of shear friction. Eighty-four push-off shear friction specimens were cast using the SCC mix. Joint conditions for the specimens included uncracked, pre-cracked, and cold-joints. Uncracked and pre-cracked specimens used both epoxy- and non-epoxy-coated shear stirrups. Cold-joint specimens used both the SCC mix and the conventional concrete mix. Joint-conditions of the cold-joint specimens included a one-hour cast time, a seven-day joint with a clean shear interface, and a seven-day joint with an oiled shear interface. The shear friction specimens were tested using a pure shear method and their results were compared to the current American Concrete Institute code equation.
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Muizzu, Mohamed. "Thermal and time-dependent effects on monolithic reinforced concrete roof slab-wall joints." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509019.
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Ledin, Jonatan, and Christensen Oskar. "Cracking Assessment of Concrete Slab Frame Bridges Exposed to Thermally Induced Restraint Forces." Thesis, KTH, Betongbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169588.
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The usage of linear 3D FEA is widespread within the bridge design community, and although this tool provides substantial benefits in the design process, there are certain practical issues related to the application of this analysis tool. A situation in which such an issue prevails is when linear 3D FEA is used to analyze restraint forces due to thermal shrinkage or expansion in concrete slab frame bridges. Effects related to restraint forces in concrete are difficult to model and predict as these forces differ significantly in nature from external loads, and dealing with them in practical design situations is complicated. In this thesis, cracking due to restraint forces in concrete slab frame bridges was investigated using 3D non-linear FE-analyses in the software package ATENA 3D. Using volumetric finite elements, attempts were made to realistically capture the load response and cracking behavior of concrete slab frame bridges subjected to restraint forces induced by temperature differences among members. The initial parts of this thesis aims to find appropriate modelling techniques and material models for the prediction of cracks due to restraint forces in base restrained walls using a previously reported experimental research project as reference. Comparative simulations were performed, using crack widths and crack patterns as comparate. Overall good correspondence was obtained with an exception of deviation in cracks formed at locations near the restrained corners where crack widths were overestimated in the simulations. The technique used to model the restrained boundary proved to be highly influential in the context of obtaining realistic results. Subsequent to the comparative study, a parametric study was performed where the correlation between crack widths and selected attributes was investigated. The parameter which exhibited the most distinct influential effect on the results was the length-to-height (L/H) ratio of the wall. The applicability of a crack control approach intended for crack width estimation in liquid retaining and containment structures made of concrete exposed to thermally induced restraint forces, given in EN 1992-3, was then evaluated for use in design of concrete frame bridges. This approach proved to return conservative results for walls with low L/H-ratios when compared to results produced in the numerical simulations. Finally, a NLFE (non-linear finite element) model of a concrete slab frame bridge designed by the consultancy company Tyréns AB was composed and tested. Different procedures of applying temperature differences between front wall and bridge deck were evaluated. This study indicated that the width of cracks induced by lateral restraint forces decreased when temperature was modelled applying a discrete thermal gradient to members in contact with back filling material compared to using a uniform temperature in these members when temperature differences between bridge deck and wall was simulated. The interacting effects of permanent external load effects and restraint forces were also investigated. Crack widths from NLFE simulations were then compared with corresponding results calculated using linear FEA results as input for design equations given in EN 1992-1-1. The latter resulted in estimated cracks more than 10 times wider than that obtained in the simulations, while crack widths predicted using the EN 1992-3 approach showed better correspondence to the NLFE results.
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MONTALVERNE, ALEXANDRE MIRANDA. "DESIGN OF CONCRETE SLAB PANELS USING THE FINITE ELEMENT METHOD AND MATHEMATICAL PROGRAMMING." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1998. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2059@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICONeste trabalho apresenta-se ferramentas computacionais para o projeto de lajes maciças de concreto armado. O projeto de lajes é feito utilizando-se uma análise elástica, elasto- plástica perfeita, um dimensionamento ótimo utilizando programação matemática e um projeto pela análise plástica. O projeto convencional de lajes de concreto armado tem sido feito a partir de esforços solicitantes determinados pela hipótese de comportamento linear elástico do material. Utilizando-se as ferramentas computacionais desenvolvidas neste trabalho é proposto um procedimento de projeto de lajes maciças de concreto armado que utiliza esforços solicitantes obtidos através de uma análise elasto-plástica perfeita desenvolvida pelo método dos elementos finitos. O dimensionamento das armaduras ortogonais, positivas e negativas, em cada ponto da laje é feito de modo a atender aos critérios de resistência definidos em função dos momentos de flexão e de torção e de maneira a se ter o menor consumo de aço. Os estados limites de utilização correspondentes à flecha da laje e à abertura de fissuras também são considerados no projeto. A análise elástica e elasto-plástica perfeita das lajes, descritas pelo seu plano médio e discretizadas pelo método dos elementos finitos, são feitas em regime de pequenos deslocamentos com formulação consistente em deslocamentos. Na análise elasto- plástica perfeita é utilizado o algoritmo de Newton-Raphson para solução das equações de equilíbrio a nível global da estrutura. As relações da Teoria da Plasticidade são resolvidas a nível local, ou seja, para cada ponto de Gauss da estrutura discretizada. O problema de retorno das tensões na análise elasto-plástica perfeita é formulado como um problema de Programação Matemática (PM). O Método dos Pontos Interiores proposto por Herskovits (HERSKOVITS, 1995) é utilizado como algoritmo de retorno das tensões na análise elasto-plástica perfeita.
In this work it is presented computational methodologies for the design of reinforced concrete massive slabs. The design of the slabs is made using an elastic and perfect elastoplastic analysis, an optimum design using mathematical programming and a plastic analysis project. The conventional project of reinforced concrete slabs has been made starting from efforts determined by the hypothesis of linear elastic behavior of the material. Using the computational methodologies developed in this work, it is proposed a procedure of design of reinforced concrete massive slabs that uses efforts obtained through a perfect elasto-plastic analysis developed by the finite element method. The design of the orthogonal reinforcements, positive and negative, in each point of the slab is made in order to assist the yield criteria defined in function of the bending and torsion moments and in order to obtain the lowest consumption of reinforcement. The limit states of serviceability corresponding to the slab deflection and crack opening are also considered in the design.The elastic and perfect elasto-plastic analyses of the slabs, described by their medium plan and discretized by the finite element method, are performed under the hypothesis of small displacements with consistent formulation in displacements. In the perfect elasto-plastic analysis, the Newton-Raphson algorithm is used to solve the equilibrium equations at global level of the structure. The relationships of the Plasticity Theory are resolved at local level,that is, for each Gauss point of the iscretized structure. The return mapping problem in the perfect elasto- plastic analysis is formulated as a problem of Mathematical Programming (PM). The Method of the Interior Points proposed by Herskovits (HERSKOVITS, 1995) is used as a return mapping algorithm in the perfect elasto-plastic analysis.
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Morrison, Jill A. "Effects of slab Shape and load transfer Mechanisms on Portland cement concrete pavement." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1177012605.
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ALJhayyish, Anwer K. "Optimizing Slab Thickness and Joint Spacing for Long-Life Concrete Pavement in Ohio." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1550099928352708.
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Yan, Ping Yu. "Behaviour of shearhead system between flat reinforced concrete slab and steel tubular column." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/behaviour-of-shearhead-system-between-flat-reinforced-concrete-slab-and-steel-tubular-column(7a3b5496-ca58-4a85-8028-3f64ad0eeddd).html.
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This thesis presents the results of an experimental, numerical and analytical study to develop a design method to calculate punching shear resistance for a new shearhead system between tubular steel column and reinforced concrete flat slab. This shearhead system enables two of the most popular structural systems, i.e. reinforced concrete flat slab floor and steel tubular column, to be used to produce efficient structures of low cost and short construction time. This research investigates slabs without and with a service hole adjacent to the column. The new shearhead system should not only possess sufficient punching shear resistance, but should also be efficient for construction. The main methodology for this project was based on numerical finite element simulations verified by two full scale tests. These two tests were carried out in the University of Manchester's Structural Testing Laboratory. The two specimens had the same slab size, thickness and reinforcement ratio, but differed in the column shape (rectangular or circular), central reinforcement arrangement (continuous or discontinuous), shearhead position in the slab thickness and shearhead fabrication arrangement. Recorded load-deflection and load-strain relationships, crack development and critical perimeter were used for detailed validation of using the commercial finite element software ABAQUS. The validated ABAQUS model was used to conduct a comprehensive parametric study to investigate the effects of a number of design parameters, including the effect of varied column size, shearhead arm length, shearhead arm cross section, shearhead arm angle, amount of flexural reinforcement, slab thickness, shearhead positions and hole positions. The main conclusion from the parametric study was that the shearhead system could be treated as an enlarged column in normal flat slab structure. The parametric study enabled pressure distribution below the shearhead arms to be approximated for checking whether the shearhead arms would be sufficient for the enlarged column assumption to be valid. The parametric study results were also used to determine the effective depth of the flat slab and critical punching shear perimeter of the slab with and without a service hole.Using the enlarged column assumption, the punching shear resistance of all structures used in the parametric study were re-calculated using Eurocode 2 (EC2), British stand 8110 (BS8110) and American Concrete Institute code 318 (ACI 318). Comparison of calculation results using these three design methods indicates that both EC2 and BS8110 predicted very close value which reached very good agreement with the ABAQUS simulation (normally within 10%). Among these three design methods, ACI 318 was the only code that explicitly considered shearhead system. ACI 318 was not able to predict the slab critical perimeter length with good accuracy, however, its prediction of slab punching shear resistance achieved reasonably good agreement with numerical analysis results and were on the safe side. Based on these studies, a design method for calculating punching resistance of the proposed shearhead system between reinforced concrete flat slab and steel tubular column has been developed in this thesis.