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1
Lam, Wai-yin. "Plate-reinforced composite coupling beams experimental and numerical studies /." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37311797.
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Svecová, Dagmar. "Behaviour of concrete beams reinforced withFRP prestressed concrete prisms." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0006/NQ42809.pdf.
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Kamat, Anuja Ganesh. "Split Concrete Model for Shear Behavior of Concrete Beams." Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/193611.
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Split Concrete Model (SCM) is a unified approach towards modeling shear behavior in concrete. SCM is essentially a rational model which is evaluated and modified using a large experimental database.The shear strength of the concrete beam is modeled as the sum of the contribution of concrete, transverse reinforcement, longitudinal reinforcement and bond between concrete and longitudinal reinforcement. Concrete does not contribute to the shear strength after the formation of the crack. In SCM, this is shown to be accurately modeled by only considering the second branch of the critical crack while computing the contribution of concrete towards shear strength of the beam. Formation of the second branch of the critical crack and immediate subsequent failure of the beam has been compared to the split-cylinder test, which forms the conceptual basis of SCM.SCM computes the concrete contribution using the split tensile strength and the area under compression of the concrete beam. For cases where a split-cylinder test is not performed, a mathematical model is proposed to compute the split tensile strength using the compressive strength of concrete available from experimental results. This model is proposed using advanced statistical methods, including weighted residuals and Box-Cox transformation and is validated using various statistical procedures. The transverse reinforcement contributes to the shear strength of the concrete beam only after the formation of the crack. In SCM, this is shown to be accurately modeled by only considering the first branch of the critical crack while computing the contribution of the transverse reinforcement towards shear strength of the beam, instead of the conventional approach of considering the entire length of the crack. The contribution of the longitudinal steel and bond between concrete and longitudinal steel and concrete is accurately modeled unlike the conventional approaches which do not consider this contribution.Evaluation using the database shows that SCM can predict accurate results for all ranges of strength, depth, reinforcement ratio, and shear span to depth ratio of the beam. This shows that all the influencing parameters for concrete shear strength have been correctly modeled in SCM. SCM gives more accurate results as compared to current codified approaches as verified with design examples. Finally, specific recommendations have been made indicating how the shear design requirements in the current ACI code can be modified.
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Gurbuz, Mustafa Ispir Barnes Robert W. "Shear strengths of end regions of prestressed self-consolidating concrete beams." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Civil_Engineering/Thesis/Gurbuz_Mustafa_18.pdf.
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Levy, Kelly Rebecca. "Bond behavior of prestressed reinforcement in beams constructed with self-consolidating concrete." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/LEVY_KELLY_6.pdf.
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Baczkowski, Bartlomiej Jan. "Steel fibre reinforced concrete coupling beams /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202007%20BACZKO.
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Chang, Peter. "Fracture characteristics of reinforced concrete beams." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65925.
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Ghavam-Shahidy, Hamid. "Lightweight aggregate reinforced concrete deep beams." Thesis, University of Dundee, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503556.
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Chana, Palvinder Singh. "Shear failure of reinforced concrete beams." Thesis, University College London (University of London), 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282869.
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Wang, Zhongsheng. "VIbration behaviour of prestressed concrete beams." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420369.
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Fang, Libin. "Shear enhancement in reinforced concrete beams." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/25113.
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The shear failure of reinforced concrete beams has been widely investigated over many years. Despite this, there is no consensus on the relative importance of the underlying mechanisms of shear resistance. The main objective of this thesis is to develop improved design guidelines for shear enhancement in beams with multiple concentrated loads applied on their upper side within a distance of 2d from the edge of supports (where d is the beam effective depth). The research involves a combination of laboratory testing, nonlinear finite element analysis and analytical work. Many tests have been carried out on beams with single point loads within 2d of supports but only a handful on beams with multiple point loads within 2d of supports. This is a significant omission since such loading commonly arises in practice. The author carried out a series of tests on beams loaded with up to two point loads within 2d of supports. The tests were designed to investigate the influences on shear strength of loading arrangement, cover and bearing plate dimensions. The latter two were varied to investigate the underlying realism of key assumptions implicit in the Strut and Tie Modelling (STM) technique. Detailed measurements were made of the kinematics of the critical shear crack. These measurements were used to assess the relative contributions of aggregate interlock, dowel action and the flexural compressive zone to shear resistance. Novel STMs are proposed for modelling shear enhancement in simply supported and continuous beams. NLFEA is used to assist in the development of the STM. The STM are validated with test data and are shown to give reasonable strength predictions that are of comparable accuracy to the author's NLFEA. STM gives particularly good predictions of shear resistance if the strut strengths are calculated in accordance with the recommendations of the modified compression field theory rather than the recommendations of Eurocode 2, which can result in strength being overestimated. However, the STM are shown to overestimate the influences of bearing plate dimensions and cover on shear resistance.
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Green, Jeremy Robert, and Jeremy Robert Green. "Behaviour of reinforced concrete deep beams." Master's thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/23219.
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Twenty five model beams were progressively loaded to failure in order to investigate the influence of the following variables on the behaviour of reinforced concrete deep beams : i) Concrete compressive strength ii) Reinforcement iii) Geometry. The model beams were all of 1500mm span, with a depth of 750mm. This span to depth ratio of 2 corresponds to the upper limit, to which the recommendations for deep beam design applies, as provided by many current codes of practice. Methods currently in use for the design of reinforced concrete deep beams were reviewed and compared. The experimental results were compared with the predictions of these design methods. This comparison revealed a large lack of agreement in the predictions of the cracking and ultimate strengths of deep beams.
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Svecova, Dagmar Carleton University Dissertation Engineering Civil and Environmental. "Behaviour of concrete beams reinforced with FRP prestressed concrete prisms." Ottawa, 1998.
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Pan, Jinlong. "Crack-induced debonding failure in fiber reinforced plastics (FRP) strengthened concrete beams : experimental and theoretical analysis /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202005%20PAN.
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Ahmed, Ahmed Kamal El-Sayed. "Concrete contribution to the shear resistance of FRP-reinforced concrete beams." Thèse, [S.l. : s.n.], 2006. http://savoirs.usherbrooke.ca/handle/11143/1784.
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趙作周 and Zuozhou Zhao. "Nonlinear behaviour of reinforced concrete coupling beams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31243927.
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Zhao, Zuozhou. "Nonlinear behaviour of reinforced concrete coupling beams /." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23589395.
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Lee, Hon. "Fatigue behavior of concrete beams prestressed with glass fiber reinforced plastic (GFRP) tendon /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202007%20LEE.
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Yapa, Hiran Deshantha. "Optimum shear strengthening of reinforced concrete beams." Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/265518.
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External prestressed carbon fibre reinforced polymer (CFRP) straps can be used to strengthen shear deficient reinforced concrete (RC) structures. The strengthening system is associated with a number of parameters including the number of straps, strap locations, strap stiffness, and strap prestress. The initial goal of this research was to identify the optimum values for these parameters in order to design an efficient and effective shear retrofitting system. The shear friction theory (SFT) and modified compression field theory (MCFT) were identified as potential predictive theories to model the shear behaviour of RC beams retrofitted with CFRP straps. Possible modifications to the theories to reflect CFRP prestressed straps were investigated. Two popular optimisation algorithms namely the genetic algorithm (GA) and particle swarm optimisation (PSO) were coded and tested with six test functions. These algorithms were used to find the optimum shear retrofitting configurations and also to reduce the computational cost associated with the SFT and MCFT evaluations. An experimental investigation was carried out to validate the SFT and MCFT predictions for various CFRP strap configurations. The investigation consisted of an unstrengthened control beam and five CFRP strengthened beams. The shear behaviour of the beams was significantly influenced by the CFRP strap configurations. A critical load level where the beam stiffness started to deteriorate significantly was identified. It was found that there was a correlation between this load level and the yielding of the internal shear links and a rapid increase in crack openmg. The SFT and MCFT were validated using the experimental results. The peak shear capacities predicted using the SFT were more consistent with the stiffness deteriorating loads identified in the experimental investigation than with the ultimate loads of the beams. The reinforcement forces and crack opening values found from the SFT were consistent with the experimental results. The MCFT predicted the total shear response, ultimate shear capacity, crack opening, and internal and external reinforcement forces in the beams. The accuracy of the MCFT predictions reduced slightly when either the strap configuration was highly nonuniforrn or the initial prestress level in the straps was relatively low. The shear link yielding load levels predicted by the MCFT were found to be similar to the SFT predictions. By using the coded optimisation algorithms in combination with the SFT or MCFT, the optimum CFRP strap configurations were found for a selected case study. Both theories predicted an offset for the optimum strap locations from the locations associated with equal spacings along the shear span. A reasonable agreement between the SFT and MCFT predictions for the optimum shear strengths and strap locations was observed. A parametric study demonstrated that the concrete strength, internal shear link locations, beam depth, and shear span to depth ratio of the beam do not significantly influence the optimum strengthening configurations for the CFRP strap system. External prestressed carbon fibre reinforced polymer (CFRP) straps can be used to strengthen shear deficient reinforced concrete (RC) structures. The strengthening system is associated with a number of parameters including the number of straps, strap locations, strap stiffness, and strap prestress. The initial goal of this research was to identify the optimum values for these parameters in order to design an efficient and effective shear retrofitting system. The shear friction theory (SFT) and modified compression field theory (MCFT) were identified as potential predictive theories to model the shear behaviour ofRC beams retrofitted with CFRP straps. Possible modifications to the theories to reflect CFRP prestressed straps were investigated. Two popular optimisation algorithms namely the genetic algorithm (GA) and particle swarm optimisation (PSO) were coded and tested with six test functions. These algorithms were used to find the optimum shear retrofitting configurations and also to reduce the computational cost associated with the SFT and MCFT evaluations. An experimental investigation was ca1Tied out to validate the SFT and MCFT predictions for various CFRP strap configurations. The investigation consisted of an unstrengthened control beam and five CFRP strengthened beams. The shear behaviour of the beams was significantly influenced by the CFRP strap configurations. A critical load level where the beam stiffness started to deteriorate significantly was identified. It was found that there was a correlation between this load level and the yielding of the internal shear links and a rapid increase in crack opening. The SFT and MCFT were validated using the experimental results. The peak shear capacities predicted using the SFT were more consistent with the stiffness deteriorating loads identified in the experimental investigation than with the ultimate loads of the beams. The reinforcement forces and crack opening values found from the SFT were consistent with the experimental results. The MCFT predicted the total shear response, ultimate shear capacity, crack opening, and internal and external reinforcement forces in the beams. The accuracy of the MCFT predictions reduced slightly when either the strap configuration was highly nonuniform or the initial prestress level in the straps was relatively low. The shear link yielding load levels predicted by the MCFT were found to be similar to the SFT predictions. By using the coded optimisation algorithms in combination with the SFT or MCFT, the optimum CFRP strap configurations were found for a selected case study. Both theories predicted an offset for the optimum strap locations from the locations associated with equal spacings along the shear span. A reasonable agreement between the SFT and MCFT predictions for the optimum shear strengths and strap locations was observed. A parametric study demonstrated that the concrete strength, internal shear link locations, beam depth, and shear span to depth ratio of the beam do not significantly influence the optimum strengthening configurations for the CFRP strap system.
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Fazio, Robert. "Flexural behaviour of corroded reinforced concrete beams." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29592.pdf.
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Ball, Ryan. "Experimental analysis of composite reinforced concrete beams." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1177002341.
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Sokolov, Aleksandr. "Tension stiffening model for reinforced concrete beams." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100803_110628-45999.
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Modelling behaviour of cracked tensile concrete is a complicated issue. Due to bond with reinforcement, the cracked concrete between cracks carries a certain amount of tensile force normal to the cracked plane. Concrete adheres to rein-forcement bars and contributes to overall stiffness of the structure. The phe-nomenon, called tension-stiffening, has significant influence on the results of short-term deformational analysis. Assumption of a tension-stiffening law has great influence on numerical results of load – deflection behaviour of reinforced concrete members subjected to short – term loading. Under wrong assumption of this law, errors in calculated deflections, particularly for lightly members, may exceed 100 %. Most known tension-stiffening relationships relate average stresses to average strains. However, some experimental and theoretical investi-gations have shown that tension-stiffening may be affected by other parameters. The scientific supervisor of the thesis has proposed a tension-stiffening model depending on reinforcement ratio. This model has been developed using experi-mental data reported in the literature. Besides, concrete shrinkage effect was not taken into account. The main objective of this PhD dissertation is to propose a tension-stiffening law for bending RC members subjected to short-term loading with eliminated concrete shrinkage effect.Gelžbetonis yra kompozitinė medžiaga, kurios komponentai yra betonas ir plieninė armatūra. Kaip žinoma, betono stipris tempiant yra 10-20 kartų mažesnis nei stipris gniuždant. Atrodytų, kad tempiamojo betono įtaka, atlaikant įrąžas skerspjūvyje, yra nereikšminga. Iš tiesų, nustatant lenkiamųjų elementų stiprumą normaliniame pjūvyje, tempiamo betono įtempių galima nevertinti. Kita vertus, skaičiuojant įlinkius, neįvertinus tempiamojo betono įtakos, gali būti daroma didesnė nei 100 % paklaida. Adekvatus supleišėjusio tempiamojo betono įtakos įvertinimas, nustatant trumpalaike apkrova veikiamų gelžbetoninių elementų deformacijas, yra bene svarbiausia ir sudėtingiausia problema. Plyšio vietoje betonas negali atlaikyti tempimo įtempių, todėl visą įrąžą atlaiko armatūra. Kadangi plyšyje ir gretimuose pjūviuose armatūra praslysta betono atžvilgiu, kontakto zonoje atsiranda tangentiniai įtempiai. Šie įtempiai perduodami betonui, todėl jis atlaiko tempimo įtempius. Armatūros ir betono sąveika ruožuose tarp plyšių standina gelžbetoninį elementą. Supleišėjusio betono gebėjimas atlaikyti tempimo įtempius vadinama tempimo sustandėjimu (angl. tension stiffening). Šis efektas dažniausiai modeliuojamas supleišėjusio betono įtempių ir deformacijų diagrama, taikant vidutinių plyšių koncepciją. Tuomet neatsižvelgiama į diskrečius plyšius, o supleišėjęs betonas traktuojamas kaip ortotropinė medžiaga su pakitusiomis savybėmis. Dauguma tempimo sustandėjimo modelių įvertina betono įtempių... [toliau žr. visą tekstą]
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Fazio, Robert 1970. "Flexural behaviour of corroded reinforced concrete beams." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27219.
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This report presents the results of a laboratory investigation of the influence of the corrosion process on the flexural capacity such as strength, deflection and steel and concrete strains in reinforced concrete beams. Examination of the behaviour of crack development was also examined.Fourteen simply supported concrete beams were cast and subjected to two third point concentrated loads, increased monotonically until failure. The strength, strain and crack development data were recorded to assess the corrosion rate and its effect on the steel bars.
An electrochemical system was used to achieve the different corrosion levels. The specimens were immersed in a 5 percent of sodium chloride by weight of water for a period of one to thirty weeks. An initial voltage of 1 volt was impressed through the beams to initiate and to accelerate the corrosion process. A steel plate was immersed in the solution to act as a cathode and force the steel reinforced concrete beam to act as an anode.
The report discusses the defects and environmental factors influencing the corrosion process. (Abstract shortened by UMI.)
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羅文惠 and Man-wai Law. "Strain energy capacity of reinforced concrete beams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31207704.
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Tan, Chuan Ming. "Nonlinear vibrations of cracked reinforced concrete beams." Thesis, University of Nottingham, 2003. http://eprints.nottingham.ac.uk/28976/.
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Although a great deal of work in investigating the possibility of using linear vibration techniques to detect damage in bridges has been carried out over the past 25 years, there are still some major concerns, such as poor sensitivity of modal parameters to damage, requirement of baseline data, need of measuring excitation force as well as environmental effects. Nonlinearity in the vibration characteristics when the structure is damaged further complicates the problem and causes doubts on the feasibility of applying these techniques on actual structures. Understanding of the nonlinear behaviour is therefore crucial. The aim of the work presented herein is to improve the current understanding of the nonlinear vibration characteristics of reinforced concrete beams and to assess its importance to the subject of structural health monitoring of bridges. These non-linear vibration characteristics were studied by conducting harmonic excitation vibration tests on reinforced concrete beams at various damage levels. In order to detect and characterise the nonlinear behaviour, both linear and nonlinear system identification techniques were used. Results indicated that the responses of the tested beams showed marked softening behaviour and that this non-linear vibration behaviour varied with increasing damage. The restoring force surface technique was applied to the test data and results suggested that cracks in reinforced concrete beams never fully closed in the vibration cycle. Existing phenomenological models suggested by other researchers were investigated and compared with the experimental results. The study confirmed that a bilinear crack model would not be sufficient to replicate the observed vibrating cracked reinforced concrete beams' behaviour. Based on these phenomenological models, an empirical model was derived. Using the empirical crack model proposed, the author suggested a means of estimating the ratio of cracked and uncracked stiffness of a vibrating cracked reinforced concrete beam. The author further suggested a possible routine for structural health monitoring for reinforced concrete beam and stressed that it could be extended for more complicated structures, like bridges. To improve understanding of the nonlinearities in the vibration characteristics, a damage mechanics model of cracked reinforced concrete beam was suggested. Based on strain softening behaviour of concrete material under tensile force, the model is capable of including damage in the form of a moment rotation relationship over the cracked region. Results from the vibration analysis of the model were compared with experimental data.
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Yang, Zhenjun. "Discrete crack modelling of plated concrete beams." Thesis, University of Wolverhampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247276.
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Strengthening reinforced concrete (RC) beams using externally bonded steel plates or fibre reinforced polymer (FRP) composites to enhance their structural performance has been paid great attention in recent years. RC beams strengthened in such way (plated RC beams) have many failure modes different from those of conventional concrete beams. A better understanding on the behaviour of the strengthened beams is essential for safe and economical design of strengthening schemes. This thesis presents research into discrete crack modelling of plated RC beams using a specialised computer program developed in this research. A key factor affecting the behaviour and reliability of strengthened concrete structures is the bond strength between the steel or FRP plate and the concrete substrate. A literature review has shown that many different methods have been used to test this bond strength. An extensive analysis on the stress distribution in various test set-ups was conducted using the finite element analysis (FEA). Results show that stress distribution can be significantly different among different set-ups, for similar materials and geometry. The bond strength and failure modes can be significantly dependent on the adopted test method. These suggest that it is important to develop a standard test method so that test results from different sources are comparable. The research studied a number of issues in using a discrete crack model based FEA method to model the behaviour of plated RC beams: Firstly, extensive FEA carried out in this research shows that the accuracy of predicted stress intensity factors may be significantly improved by adding a rosette around the crack tip in linear elastic fracture mechanics (LEFM) problems, but the optimum rosette size is problem dependent. In order to avoid this uncertainty, a new procedure was devised which resulted in good predictions even for very coarse meshes. Secondly, a mixed-mode discrete crack LEFM based FEA model was developed to model the behaviour of plated RC beams. Automatic multiple crack propagation during the whole loading process until the failure of the structure was modelled. Simulation of the concrete cover separation failure mode has been particularly success. Numerical results confirmed that the bonding of a plate leads to smaller and more closely spaced cracks than the un-strengthened beam. For plated beams, the cracking can have significant effect on the stress distribution in the FRP plates. The length of the plate has a significant effect on the failure mode. Finally, 16 numerical strategies were compared for solving problems associated with sharp snap-back behaviour encountered in modelling discrete crack propagation in concrete beams using non-linear fracture mechanics. A four-point single notched shear beam with nonlinear interface elements representing the discrete cracks was used for this purpose. The results show that the effectiveness and efficiency may vary considerably from one to another, with the local arc-length based procedures in conjunction with tangential stiffness strategy and reversible unloading model being the most robust.
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Chan, Andrew Kay Ching. "Impact behaviour of model prestressed concrete beams." Thesis, University of Sheffield, 1986. http://etheses.whiterose.ac.uk/3484/.
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This research work investigates the impact behaviour of prestressed concrete beams. A total number of forty 1000 mm long model beams with a rectangular section of 44 x 65 mm were cast. The beams were divided into four with ten beams in each series. Each beam was prestressed by four 1.6 mm diameter piano vire3 and the shear reinforcement va3 varied from series to series. The test rig available was modified so that the beam could have pin-end supports with a span of 600 mm and a static or impact load could be applied at the midspan. A total number of 40 static tests (8 static and 32 post-impact-static) and 32 impact tests were performed. The static load was applied by a screw jack via a one meter long steel pressure bar. The impact load was produced by the impact of a 350 mm steel cylinder projected at velocities of 4 to 17 m/s by compressed air onto the same pressure bar. In each impact test, the impact force-time history was recorded by the electrical resistance foil strain gauges attached on the pressure bar. The transient deflections at various positions along the span were measured by linear variable differential transducers and the reaction was measured by aluminium load cells on which electrical resistance strain gauges were fixed. A dynamic plastic model proposed by Ezra(90) was developed and applied in conjunction 'with the one-degree of freedom system to evaluate the maximum dynamic midspan deflection, reactions, energy absorption capacity and the initial impact beam velocity. A comparison was made between the predicted and the experimental results.
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Houmsi, Ahmed. "Shear strength of reinforced concrete haunched beams." Thesis, University of Strathclyde, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241959.
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IUNES, YVELYNE BIANCA FERREIRA. "OPTIMUM TENDON PROFILES IN PRESTRESSED CONCRETE BEAMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1998. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=1402@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORUNIVERSIDADE FEDERAL DO PARÁ
O presente trabalho contém a formulação, implementação e teste de um modelo para determinação do traçado ótimo de cabos de protensão, bem como do valor da força de protensão mínima correspondente, em vigas isotáticas e hiperestáticas. Na formulação, será considerado que o cabo de protensão possui um desenvolvimento segmentado em parábolas do segundo grau, onde o comprimento dessas parábolas serão pré- estabelecidos. Serão feitas ainda simplificações em relação à força de protensão e às perdas de protensão. Com a introdução de tais simplificações e com um artifício de mudança de variáveis, estaremos diante de um problema de programação linear, onde as incógnitas do problema serão a força de protensão e os coeficientes dos trechos de parábolas que representam a geometria do cabo. O objetivo desse problema de programação linear, será minimizar o custo da protensão, de forma que algumas restrições, previamente estabelecidas, sejam atendidas. Tais restrições, limitarão a geometria do cabo, uma vez que o mesmo deve ser contínuo, representado por curvas suaves, e estar contido dentro da viga, e limitarão as tensões nos bordos extremos da viga de forma que as Normas Brasileiras NBR 8681, NBR 7197 e NBR 7187 sejam atendidas. Serão considerados diversos casos de carga e as seções de estudo serão pré-definidas. Como resultado do projeto teremos o traçado ótimo de um cabo médio, e a força de protensão mínima P0, onde já estarão incluídas as perdas imediatas. A implementação da formulação foi desenvolvida em linguagem C, padrão ANSI, o que garante que o mesmo código possa ser compilado em computadores diferentes e por compiladores diferentes, facilitando a portabilidade do programa. Para a otimização, foi utilizado o programa comercial LINDO- Linear Interactive and Discrete Optimizer, que permite uma interação com o usuário, é prático e de grande eficiência. Serão testados e analisados quatro exemplos, variando em sua complexidade. Das quatro vigas testadas, uma foi apresentada por Calçada (1993) em seu artigo "Traçado Óptimo de Cabos de Pré-esforço em Pórticos", e as outras três foram projetadas por engenheiros em escritórios de cálculo estrutural. As duas soluções de projeto, a dada pelo programa e a obtida pelos escritórios, são comparadas de modo a validar tanto a formulação como o programa implementado.
This work is concerned with the formulation, implementation and test of a model for determination of the minimum prestressing force and the optimum tendon profile, to prestressed isostatics and hiperestatics beams. It will be considered in formulation, that the prestressing cable has a development segmented in second grade parabolas, in which the length of each one will be predetermined. In addition, simplifications will be considered with regard to the prestressing force and the prestressing losses. With these assumptions and an artifice of variables change, linear programming problem will be obtained, where the variables will be the prestressing force and the parabolas coefficients that represent the cable geometry. The objective of this linear programming problem will be to minimize the prestressing cost, based on some constraints. These constraints will limit the cable geometry, since this one has to be continue, represented for smooth curves and to be inside of the beam, and will limit the stresses at the top and at the bottom fibers of each studied sections according to Brazilian Codes NBR 8681, NBR 7197 e NBR 7187. Different loads cases will be considered and the studied sections will be predetermined. As project result, we will have an optimum tendon medium profile and the minimum prestressing force P0, where the immediate losses will be included. The formulation implementation was developed in "C" language, ANSI standard, which guarantees that the same code can be compiled in different computers and for different compilers, making the program portability easy. For optimization, the commercial program LINDO- Linear Interactive and Discrete Optimizer was used, which allows interaction with the user, is practical and very efficient. Four examples with different complexity will be tested and studied. From four beams tested, one was presented by Calçada (1993) in his paper "Traçado Óptimo de Cabos de Pré-esforço em Pórticos", and the other ones were designed by engineers in structural design offices. The two design solutions, the one given by the program and the other obtained by the offices, are compared in order to validate both the formulation and the program implemented.
El presente trabajo contiene la formulación, implementación y pruebas de un modelo para determinación del trazado ótimo de cables de protensión, bien como del valor de la fuerza de protensión mínima correspondiente, en vigas isotáticas y hiperestáticas. En la formulación, será considerado que el cable de protensión posee un desarrollo segmentado en parábolas de segundo grado, de dimensiones prestablecidas. Se considerarán simplificaciones en relación a la fuerza de protensión y a las pérdidas de protensión. Con la introducción de tales simplificaciones y con un artificio de cambio de variables, estaremos frente a un problema de programación lineal, donde las incógnitas del problema serán la fuerza de protensión y los coeficientes de los intervalos de parábolas que representan la geometría del cable. El objetivo de este problema de programación lineal será minimizar el costo de la protensión, de forma que sean atendidas algunas restricciones, previamente establecidas. Tales restricciones, limitarán la geometría del cable, que debe ser contínuo, representado por curvas suaves, y estar contenido dentro de la viga; y limitarán las tensiones en los bordes extremos de la viga para atender las Normas Brasileiras MBR 8681, MBR 7197 y MBR 7187. Se considerarán diversos casos de carga y las secciones de estudio serán predefinidas. Como resultado del proyecto tendremos el trazado óptimo de un cable medio y la fuerza de protensión mínima P0, donde estarán incluidas las pérdidas inmediatas. La implementación fue desarrollada en lenguaje C, padrón ANSI, que garantiza que el mismo código pueda ser compilado en computadores diferentes y por compiladores diferentes, facilitando la portabilidad del programa. Para la optimización, fue utilizado el programa comercial LINDO - Lineal Interactive and Discrete Optimizer, que permite una interacción con el usuario, es práctico y de gran eficiencia. Se analizaron cuatro ejemplos, variando su complejidad. De las cuatro vigas, una fue presentada por Calzada (1993) en su artículo "Trazado Ótimo de Cabos de Pré-esforzo en Pórticos", y las otras tres fueron projectadas por ingenieros de cálculo extructural. Las dos soluciones del proyecto, la dada por el programa y la obtenida por los ingenieros, son comparadas para evaluar la formulación del modelo y la implemantación del programa.
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Gomez, Nicolas M. Eng Massachusetts Institute of Technology. "Design of prestressed, fabric-formed concrete beams." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111507.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 60-62).
Fabric forms and prestressing are both technologies for concrete structures that allow for less material to do more work. This thesis seeks to assess the feasibility and performance of fabric formed, prestressed beams with a keyhole cross-section, while varying parameters such as concrete strength, loading, beam depth, and prestressing force. They are designed for flexure via a sectional method, starting with the critical midspan section, and each section is iterated in an effort to minimize the beam weight. Beam strength and deflections are determined and once met, they are compared to more traditional prestress designs. Such beams are found to be governed primarily by strength criteria, as deflections are found to be minimal. These fabric formed beams can use nearly an identical amount of material as conventional I-beams with a constant cross-section, while requiring a higher prestressing force. Prestressed fabric formed beams are less efficient than an I-beam section, but should not be discounted as a viable element, because of their aesthetic appeal and further potential for optimization.
by Nicolas Gomez.
M. Eng.
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Sarieddine, Marwan. "Optimal design of fabric formed concrete beams." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90155.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 57-58).
The topic of fabric formwork has emerged as a response to the rising need for material efficient designs that also incorporate attractive aesthetic and construction related features. The thesis approaches the topic of the optimization of the design of fabric formed concrete beams. The thesis proposes two methods: an analytical optimization method and a feasible region method. The optimum design of fabric formed reinforced concrete beams is discussed first and a sample output of the optimum design based on minimizing the cost of a cross-section is produced. A relatively direct design process based on simple polynomials is established that can conveniently guide designers to produce optimal designs. Based on sample results, savings of up to 55% in material cost could be accomplished using fabric formed beams. The subject of pre-stressed fabric formed beams is then approached using the two methods. Certain additional complexities are explained and some simplifications are done in order to arrive at an optimum design using the feasible region method.
by Marwan Sarieddine.
M. Eng.
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Hristova, Elena Hristova. "Residual strength of corroded reinforced concrete beams." Thesis, Sheffield Hallam University, 2006. http://shura.shu.ac.uk/19838/.
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Currently, much research is focused on the corrosion of reinforcement in concrete members. However, none addresses the problems associated with the residual strength of reinforced concrete beams exhibiting both main and shear reinforcement corrosion simultaneously. The aim of this research, therefore, was to determine the residual strength of corroded reinforced concrete beams where various degrees of reinforcement corrosion is present in both the main and shear reinforcement. This may provide a better understanding of the performance of deteriorated reinforced concrete beams in service. One of the main causes of concrete deterioration is corrosion of the steel reinforcement and thus a reduction of the residual service life. In general, corrosion of reinforcement is believed to affect the structural performance of concrete elements in two ways. Firstly, by reducing the rebar cross sectional area, and secondly, by loss of bond strength between the concrete and steel reinforcement and resulting growth of cracks due to the formation of corrosion products at concrete/reinforcement interface. The experimental programme was carried out to provide information on the loss of strength resulting from corrosion to the main and shear reinforcement. Corrosion was induced by means of external power supplies. The test programme was divided into three series. Series I was devised to determine the residual flexural strength of reinforced concrete beams where different diameters of main (high yield) reinforcement were subjected to varying degrees of accelerated corrosion (shear strength was provided by mild steel shear reinforcement which remained unaffected by corrosion). Series II was devised to determine the residual shear strength of reinforced concrete beams where the shear (mild steel) reinforcement was subjected to varying degrees of accelerated corrosion (flexural strength was provided by high yield steel which was protected from corrosion). Finally, Series III was devised to determine the residual strength of reinforced concrete beams where both the main (high yield) and shear (mild steel) reinforcement were simultaneously corroded and the effect of this on the performance of the beam was determined. In total, 116 beams were subjected to accelerated corrosion using an impressed current imposed on the reinforcement. Each beam was loaded to failure to determine the strength loss. Four degrees of corrosion were targeted, ranging from 0% (control) to 15%, in increments of 5%.The results of the laboratory tests determined the significance of both main and shear reinforcement corrosion on the performance of deteriorated reinforced concrete beams. In addition, simplified analytical equations were developed which may assist the engineer in assessing the residual strength of corroded reinforced concrete beams.
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Cojocaru, Razvan. "Lifting Analysis of Precast Prestressed Concrete Beams." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32464.
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Motivated by Robert Mastâ s original papers on lifting stability, this research study provides a method for predicting beam behavior during lifting, with application in the construction of bridges. A beam lifting cracking limit state is developed based on analytical equations for calculating the roll angle of the beam, the internal forces and moments, the weak-axis and strong-axis deflections, and the cross-sectional angle of twist. Finite element simulations are performed to investigate the behavior of concrete beams during lifting and to validate the proposed method. Additionally, a statistical characterization of beam imperfections is presented, based on recently conducted field measurements of beam lateral sweep and eccentricity of lift supports. Finally, numerical examples for two typical precast prestressed concrete beam cross-sections are included to demonstrate the proposed method.Master of Science
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Sas, Gabriel. "FRP shear strengthening of reinforced concrete beams." Doctoral thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25881.
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The shear failure mechanisms of flexural reinforced concrete (RC) members is highly complex; its precise details cannot be explained with simple analytical relationships, and are the topic of considerable scientific debate. The studies described and examined the three most used shear theories in the world – the fixed angle truss model (45°TM), the variable angle truss model (VAT), and modified compression field theory (MCFT). These three theories rest on the assumption that a beam loaded in shear behaves as a truss. However, this assumption is applied in different ways in various codes. In this thesis, three major standards, each of which uses a different implementation of these theories (CEN, 2005; ACI-318, 2008; CSA-A23.3, 2009), were used to predict the shear force capacity of a RC railway bridge that was strengthened in flexure with near surface mounted (NSM) carbon fibre reinforced polymers (CFRP) and then tested to failure. The data obtained in this test indicated that the codes underestimated the real shear behaviour of the bridge. There are some accepted reasons for such inaccuracies, namely the use of empirically derived equations in the ACI (2008) and CSA (2009) standards and the omission of the concrete contribution in CEN (2005). Moreover, the NSM reinforcement material used exhibits elastic behaviour until the point of failure; it was found that the use of such materials introduces further decreases the accuracy of the models’ predictions. The strains that developed in the area of the bridge where shear failure was expected were monitored throughout the test using a specially-developed photographic method. The results obtained with this method were promising, especially for research purposes, since it generated reliable data using relatively affordable tools.The use of FRP for shear strengthening introduces further complications to the problem of shear in reinforced concrete members because introduces two new failure modes: debonding at the concrete interface and fibre rupture of the FRP. Extensive research has been carried out on FRP shear strengthening around the world. Much of the data gathered in these studies has been compiled in a database. By analysing this large database, it was found that the effectiveness of FRP shear strengthening is influenced by many factors, including the properties of the FRPs, the FRP strengthening configuration used, the nature of the beam’s cross-section, the shear span to depth ratio, the presence of stirrups, and the nature of the tensile reinforcement. Analysis of this database also demonstrated that most of the studies reported in the literature had focused on investigating the influence of the properties of the FRPs and the different configuration systems, and that the other factors mentioned above have been sparsely investigated if not totally ignored. The strengthening configuration and the amount of fibres influence the failure mode of the FRP and the shear force that it can carry. It appears that the side-bonded and the U-wrapped configurations are most prone to failure by debonding. This is consistent with the findings of various small experimental programs, and was confirmed by analysis of the larger dataset. These findings are relevant because failure of the FRP by debonding is more complex mechanism than is the rupture of the fibres mechanism. As is shown in this thesis, the extent to which the FRP variables (properties and strengthening configuration) can affect the point at which failure occurs and the mode by which it happens is dependent on the quantity of stirrups and tensile reinforcement in the beam, to the position of the load in relation to the size of the cross section (shear span to depth ratio), the type of strengthening configuration, the concrete and FRP properties. For design purposes, it is important to predict the shear failure of FRP shear strengthened beams with as much accuracy as possible. Therefore, a design model for debonding of the shear strengthening of concrete beams with FRP was developed and the limitations of the truss model analogy were highlighted. The fracture mechanics approach was used to analyse the behaviour of the bond between the FRP composites and the concrete. In this model, of the parameters examined, the fracture energy of concrete and the axial rigidity of the FRP are considered to be the most important. The effective strain in the FRP when debonding occurs was determined and the limitations of the anchorage length over the cross section were analysed; ultimately, a simple iterative method for shear debonding was proposed. Since the model’s predictions were considered satisfactory but not really precise, an extensive review of the literature was conducted. All of the significant theoretical models for predicting the shear capacity of FRP strengthened RC beams that have been reported over the years were analysed and commented on, and their predictions were compared to the results recorded in a preliminary experimental database. The predictions of the models that are most widely used in design were compared to the experimental results reported in the database; the model developed by the author was evaluated alongside these more established models. All of the models, including that presented in this thesis, were found to generate inaccurate predictions, but two models have been calibrated so as to provide safe estimates of the FRP shear capacity. Finally a new model for FRP shear strengthening was proposed for use in engineering. The new model was developed on the basis of an analysis of the contents of the database of experimental findings. The model incorporates several design equations adopted from various models and is set up for engineering use. The predictions of the shear force carried by the FRP strengthening material are found to be conservative.Godkänd; 2011; 20110328 (gabsas); DISPUTATION Ämnesområde: Konstruktionsteknik/Structural Engineering Opponent: Professor Giorgio Monti, University of Rome, Italy Ordförande: Professor Björn Täljsten, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Fredag den 29 april 2011, kl 13.00 Plats: F1031, Luleå tekniska universitet
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Law, Man-wai. "Strain energy capacity of reinforced concrete beams /." [Hong Kong : University of Hong Kong], 1987. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12228175.
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Ismail, Kamaran Sulaiman. "Shear behaviour of reinforced concrete deep beams." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12600/.
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RC deep beams are key safety critical structural systems carrying heavy loads over short span, such as transfer girders in tall buildings and bridges. Current design provisions in codes of practice fail to predict accurately and reliably the shear capacity of RC deep beams and in some cases they are unsafe. This work aims to develop a better understanding of the behaviour of RC deep beams and governing parameters, and to improve existing design methods to more accurately predict the shear capacity of such members. An extensive experimental programme examining 24 RC deep beams is carried out. The investigated parameters include concrete strength, shear span to depth ratio, shear reinforcement and member depth. To develop a better insight on the distribution and magnitude of developed stresses in the shear span, finite element analysis is also performed. The microplane model M4 is implemented as a VUMAT code in ABAQUS to represent the behaviour of concrete in a more reliable manner and validated against experimental tests on RC deep beams. This model is utilised in a parametric study to further investigate the effect of concrete strength, shear span to depth ratio and shear reinforcement. The experimental and numerical results show that concrete strength and shear span to depth ratio are the two most important parameters in controlling the behaviour of RC deep beams, and that shear strength is size dependent. The analysis also shows that minimum amount of shear reinforcement can increase the shear capacity of RC deep beams by around 20% but more shear reinforcement does not provide significant additional capacity. A lateral tensile strain based effectiveness factor is proposed to estimate the strength of the inclined strut to be used in strut-and-tie model. Additionally, node factors to estimate the developed strength in different type of nodes are proposed. The proposed model is evaluated against a large experimental database and the results show that it yields more accurate and reliable results than any of the existing models. The model is characterized by the lowest standard deviations of 0.26 for both RC deep beams with and without shear reinforcement and accounts more accurately for all influencing parameters.
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Al-lami, Karrar Ali. "Experimental Investigation of Fiber Reinforced Concrete Beams." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2296.
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Shear strength of fiber reinforced concrete beams was studied in this research project. Three types of fibers were examined: hooked-end steel fiber, crimped-steel fiber, and crimped-monofilament polypropylene fibers. The experimental program included five beam specimens. Two of the beams were control specimens in which one was reinforced with minimum shear reinforcement according to ACI 318, while the other one did not have any shear reinforcement. Each one of the other three specimens was reinforced with one of the above mentioned fibers by 1% volumetric ratio. In addition to the beam specimens, three prisms were also made for each type fiber to determine their toughness.
The aim of this research was to investigate the following questions for medium-high concrete strength 1) to evaluate the effectiveness of each type of fibers on the shear strength, 2) to investigate the shear strength, toughness, crack patterns and near ultimate load crack width of each beam, and 3) to determine if using 1% volumetric ratio of fibers as shear reinforcement in beams would provide adequate strength and stiffness properties comparable to reinforcing steel used as minimum shear reinforcement.
The results showed that all three types of fibers increased the shear capacity of the beam specimens more than the beam reinforced with minimum shear reinforcement. Moreover, some of the fibers used could shift the type of failure from a pure shear failure to a combined flexural-shear or pure flexural failure.
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Kong, Paul Y. L. "Shear strength of high performance concrete beams." Thesis, Curtin University, 1996. http://hdl.handle.net/20.500.11937/2600.
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An analytical and experimental investigation on the shear strength of High Performance Concrete (HPC) beams with vertical shear reinforcement or stirrups was carried out. The analytical work involved developing a theory based on the truss analogy, capable of predicting the response and shear strength of such beams subjected to combined bending moment and shear force.The experimental work comprised forty-eight beam specimens in eight series of tests. Most of the beams were 250 mm wide, 350 mm deep and had a clear span of approximately 2 metres. The largest beam was 250 mm wide, 600 mm deep and had a clear span of 3.1 metres. Test parameters included the concrete cover to the shear reinforcement cage, shear reinforcement ratio, longitudinal tensile steel ratio, overall beam depth, shear span-to-depth ratio and concrete compressive strength. The loading configurations included using one, two or four symmetrically placed concentrated loads on simply supported spans.The theory predicted the shear strength of the beams in the present study well. When beams from previous investigations were included, the theory also gave good prediction of the shear strength. Apart from this, comparisons of shear strength were also made with the predictions by the shear design provisions contained in the Australian Standard AS 3600 (1994), American Concrete Institute Building Code ACI 318-95, Eurocode EC2 Part 1 and Canadian Standard CSA A23.3-94. The AS 3600 method was found to give the best correlation with the test results among all the code methods.
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Kong, Paul Y. L. "Shear strength of high performance concrete beams." Curtin University of Technology, School of Civil Engineering, 1996. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=11337.
Full textAbstract:
An analytical and experimental investigation on the shear strength of High Performance Concrete (HPC) beams with vertical shear reinforcement or stirrups was carried out. The analytical work involved developing a theory based on the truss analogy, capable of predicting the response and shear strength of such beams subjected to combined bending moment and shear force.The experimental work comprised forty-eight beam specimens in eight series of tests. Most of the beams were 250 mm wide, 350 mm deep and had a clear span of approximately 2 metres. The largest beam was 250 mm wide, 600 mm deep and had a clear span of 3.1 metres. Test parameters included the concrete cover to the shear reinforcement cage, shear reinforcement ratio, longitudinal tensile steel ratio, overall beam depth, shear span-to-depth ratio and concrete compressive strength. The loading configurations included using one, two or four symmetrically placed concentrated loads on simply supported spans.The theory predicted the shear strength of the beams in the present study well. When beams from previous investigations were included, the theory also gave good prediction of the shear strength. Apart from this, comparisons of shear strength were also made with the predictions by the shear design provisions contained in the Australian Standard AS 3600 (1994), American Concrete Institute Building Code ACI 318-95, Eurocode EC2 Part 1 and Canadian Standard CSA A23.3-94. The AS 3600 method was found to give the best correlation with the test results among all the code methods.
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Mohamed, Ali M. S. "Peeling of plates adhesively bonded to reinforced concrete beams /." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phm6968.pdf.
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Chan, Ka-ho Enoch. "Experimental and numerical studies of concrete beams prestressed with unbonded tendons." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40988004.
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Giaccio, Craig 1974. "Flange effectiveness in the resistance of shear on RC T-beams subjected to point loads." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/5708.
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Ho, Ching-ming Johnny, and 何正銘. "Inelastic design of reinforced concrete beams and limited ductilehigh-strength concrete columns." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B27500305.
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Nixon, Jeffrey McMillan Schindler Anton K. "Evaluation of the maturity method to estimate concrete strength in field applications." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Spring/master's/NIXON_JEFFREY_32.pdf.
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Roberts, James Benson Schindler Anton K. "Evaluation of self-consolidating concrete for use in prestressed girder applications." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Thesis/ROBERTS_JAMES_43.pdf.
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Maruri, Rodolfo Felipe. "Iterative computer analysis of post-tensioned concrete beams and frames." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/19510.
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Siu, Wing-ho. "Flexural strengthening of reinforced concrete beams by bolted side plates." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43278735.
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Foo, M. H. "Behaviour of partially prestressed concrete structures under fatigue loading /." Title page, table of contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phf686.pdf.
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Li, Lingzhi, and 李凌志. "New partial interaction models for bolted-side-plated reinforced concrete beams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50899636.
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Existing reinforced concrete (RC) beams often need to be strengthened due to material deterioration or a change in usage. The bolted side-plating (BSP) technique, i.e., attaching steel plates to the side faces of RC beams using anchor bolts, effectively enhances the bearing capacity without significant loss in deformability thus receives wide acceptance. However, as a newly developed technique, only limited information is available in literature, which mainly focused on the overall load–deflection performance of lightly reinforced BSP beams. Little studies have been conducted on the partial interaction between steel plates and RC beams which is closely related to the performance of BSP beams. The longitudinal and transverse slips, which control the degree of partial interaction, have yet to be determined precisely. Accordingly, in this thesis, extensive experimental, numerical and theoretical studies on BSP beams are presented.
The experimental behaviour of BSP beams was investigated. For the first time, special effort was put in precisely measuring the profiles of longitudinal and transverse slips. In order to investigate the behaviour of BSP beams under other load cases and beam geometries, a nonlinear finite element analysis was conducted. The numerical method is more economical and capable of overcoming the difficulty in measuring the transverse slips precisely. A new approach to evaluating the transverse bolt shear force was also developed through a parametric study.
New partial interaction models were developed by isolating and considering the longitudinal and the transverse partial interaction separately. A longitudinal slip model was developed based on the BSP beam section analysis, in which different strains of steel plates and RC beams were considered but the difference in deflection hence the difference in curvature was not taken into account. Meanwhile, a piecewise linear model was also proposed for the transverse slip and bolt shear transfer by introducing Winkler’s model and defining the transverse slip as the difference in deflection. Formulas for the slips, the plate forces, the strain and the curvature factors that indicate the degree of partial interaction, were also deduced. Furthermore, these formulas allow us to evaluate the effect of partial interaction in the BSP strengthening design.
A numerical program was originally developed to evaluate the performance of BSP beams with partial interaction. The balance between strengthening effect and strengthening efficiency was also achieved by a parametric optimization study, which would simplify the design procedure of BSP strengthening significantly.
According to the numerical and theoretical results, a new design approach for BSP beams, which needs only minor modification to existing design formula for RC beams, was proposed to aid engineers in designing this type of BSP beams and to ensure proper details for desirable performance. Compared to the conventional design methods that assume a full interaction between steel plates and RC beams, this new method not only retains the features such as ease of use and fast calculation, but also yields results that are more reliable.published_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy
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Kavanaugh, Bryan Palmer Schindler Anton K. "Creep behavior of self-consolidating concrete." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Civil_Engineering/Thesis/Kavanaugh_Bryan_38.pdf.
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