Journal articles on the topic 'Scaled prestress bridge girders'
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1
Song, Chaojie, Gang Zhang, Wei Hou, and Shuanhai He. "Performance of prestressed concrete box bridge girders under hydrocarbon fire exposure." Advances in Structural Engineering 23, no. 8 (January 3, 2020): 1521–33. http://dx.doi.org/10.1177/1369433219898102.
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This article presents an approach for investigating performance of prestressed concrete box bridge girders under hydrocarbon fire exposure. A three-dimensional nonlinear finite element model, developed in computer program ANSYS, is utilized to analyze the response of prestressed concrete box bridge girders under combined effects of fire exposure duration and simultaneous structural loading. The model validation is performed using a scaled prestressed concrete box girder exposed to ISO834 fire in furnace. Subsequently, the validated model is used to investigate fire performance of prestressed concrete box bridge girders through taking into consideration some variables, namely concrete cover thickness to prestressing strands, prestress degree, load level, fire exposure length, and position. Through a case study, results from numerical analysis show that concrete cover thickness to prestressing strands and load level has significant effect on fire resistance of prestressed concrete box bridge girders. Increasing prestress degree in prestressing strands can speed up the progression of deflection (sudden collapse) in prestressed concrete box bridge girder toward the final fire exposure stage. Reducing fire exposure length or preventing fire exposure on mid-span zone can highly enhance the fire resistance of simply supported prestressed concrete box bridge girders. Failure of prestressed concrete box bridge girder, under hydrocarbon fire exposure conditions, is governed by rate of deflection failure criterion in particular cases.
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Ji, Wei, Kui Luo, and Jingwei Zhang. "Computation of Deflections for PC Box Girder Bridges with Corrugated Steel Webs considering the Effects of Shear Lag and Shear Deformation." Mathematical Problems in Engineering 2020 (July 18, 2020): 1–12. http://dx.doi.org/10.1155/2020/4282398.
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Prestressed concrete (PC) girders with corrugated steel webs (CSWs) have received considerable attention in the past two decades due to their light self-weight and high prestressing efficiency. Most previous studies were focused on the static behavior of CSWs and simple beams with CSWs. The calculation of deflection is an important part in the static analysis of structures. However, very few studies have been conducted to investigate the deflection of full PC girders or bridges with CSWs and no simple formulas are available for estimating their deflection under static loads. In addition, experimental work on full-scale bridges or scale bridge models with CSWs is very limited. In this paper, a formula for calculating the deflection of PC box girders with CSWs is derived. The longitudinal displacement function of PC box girders with CSWs, which can consider the shear lag effect and shear deformation of CSWs, is first derived. Based on the longitudinal displacement function, the formula for predicting the deflection of PC box girders with CSWs is derived using the variational principle method. The accuracy of the derived formula is verified against experimental results from a scaled bridge model and the finite element analysis results. Parametric studies are also performed, and the influences of shear lag and shear deformation on the deflection of the box girder with CSWs are investigated by considering different width-to-span ratios and different girder heights. The present study provides an effective and efficient tool for determining the deflection of PC box girders with CSWs.
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Park, Jae Hyung, Dong Soo Hong, Jeong Tae Kim, Ki Young Koo, Chung Bang Yun, and Gyuhae Park. "Wireless Sensing and Embedded Monitoring Algorithm for Damage Diagnosis in PSC Girders." Advances in Science and Technology 56 (September 2008): 420–25. http://dx.doi.org/10.4028/www.scientific.net/ast.56.420.
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In this study, a hybrid health monitoring technique that combines wireless sensing and embedded monitoring algorithms is proposed to realize the diagnosis of damage in PSC girder bridges. Firstly, a hybrid damage monitoring system that can alarm damage occurrence and classify damage-types is designed for PSC girder bridges. Secondly, smart sensor nodes that have wireless, stand-alone, sensing and monitoring capacities of acceleration and impedance are developed for hybrid health monitoring of the structures. Finally, the performance of the smart sensor nodes is evaluated using a laboratory-scale PSC girder bridge model for which acceleration and impedance signals were measured for prestress-loss and stiffness-loss cases.
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Lin, Jian Jun, Denis Beaulieu, and Mario Fafard. "Parametric study on noncomposite slab-on-girder bridges with enforced frictional contact." Canadian Journal of Civil Engineering 21, no. 2 (April 1, 1994): 237–50. http://dx.doi.org/10.1139/l94-027.
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Using post-tensioned steel rods for strengthening noncomposite slab-on-steel girder bridges has the beneficial effects of both stabilizing the steel girders laterally and developing partial composite action longitudinally. The stabilizing effect and development of partial composite action are achieved by taking advantage of friction developed at the steel–concrete interface. A bridge reinforced by this technique is expected to have a higher load-carrying capacity and better load distribution under heavy traffic loads. Prestressed rods have been successfully used to strengthen 1/3 scale noncomposite bridge models in laboratory.The concrete slab-on-steel girder bridge models reinforced by prestressed rods are analyzed numerically in this paper by the use of the finite element method. Corresponding noncomposite models are also simulated for comparison to investigate the efficiency of this strengthening technique. The effects of variables such as the number of rods, prestressing level, type of load, slab thickness, steel girder slenderness, girder spacing, and ratio of radii of gyration of steel girders on the strengthening efficiency are studied by the finite element method. A full-scale bridge is analyzed to demonstrate the effect of the proposed reinforcing technique. Key words: bridge, composite action, contact, finite element, friction, parametric study, strengthening.
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Bakht, Baidar, and Tharmalingham Tharmabala. "Steel–wood composite bridges and their static load response." Canadian Journal of Civil Engineering 14, no. 2 (April 1, 1987): 163–70. http://dx.doi.org/10.1139/l87-028.
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The proposed steel–wood composite bridges incorporate longitudinal steel girders which are composite with wood deckings consisting of longitudinal laminates. The laminated decking is usually transversely prestressed. By orienting the laminates longitudinally, advantage can be taken in longitudinal bending of the dominant modulus of elasticity of wood. The paper shows that the load-carrying capacity of an existing slab-on-girder bridge with steel girders and deteriorated noncomposite concrete deck slab can be considerably enhanced by using the proposed system. The paper presents results of static load tests on two types of shear connector, some composite beams, and half-scale model of a bridge. Test data confirm the effectiveness of the composite system. Key words: bridges, composite bridges, steel–wood composite bridges, laminated wood decks, shear connectors, composites.
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Qiao, Lan, and Shao Wen Zhang. "Analysis of the Arrangement of Prestressed Steel in Web of Continuous Concrete Box-Girder Bridges." Applied Mechanics and Materials 587-589 (July 2014): 1359–63. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1359.
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Concrete continuous box- girder bridges have a large proportion in small span and long span bridges, and it has very broad prospects for development. Along with the large-scale construction of this kind of bridge, various problems have also emerged, especially the damage of RC beam’s diagonal section in bridge girder deflection. It always appears the inclined cracks in webs which cause by principal tensile stress, so it will be the potential damage to the whole bridge. However, the existence of the vertical prestress, will make the principal tensile stress of box girder in greatly reduced. So as to make cracking resistance performance of diagonal section is better than the ordinary reinforced concrete bridge. For an engineering example, this paper puts forward several different vertical prestressed steel arrangements. Based on different decorate a form of vertical pretressd bridge girder under stress numerical simulation, it is concluded that bridge’s web principal tensile stress distribution and its variation law, and then optimize the vertical reinforcing steel arrangement, improve the overall safety of bridge structure. It can provide the reference in the process of construction when we face the similar problems in the future.
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Nguyen, Hue Thi, Hiroshi Masuya, Tuan Minh Ha, Saiji Fukada, Daishin Hanaoka, Kazuhiro Kobayashi, and Eiji Koida. "Long-term Application of Carbon Fiber Composite Cable Tendon in the Prestressed Concrete Bridge-Shinmiya Bridge in Japan." MATEC Web of Conferences 206 (2018): 02011. http://dx.doi.org/10.1051/matecconf/201820602011.
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Carbon fiber reinforced plastic (Carbon Fiber Composite Cable, CFCC) has the outstanding features in comparison with regular steel. In October 1988, CFCC was applied as the tensioning material in main girders of new Shinmiya Bridge in Ishikawa, Japan. This was the first bridge in Japan and in the world, which CFCC tendons were used in the prestressed concrete bridge to counter salt damage. To investigate the serviceability and durability of the main girders and CFCC, three full-scale test girders were fabricated in 1988. At the same time, a bending experiment was conducted on one girder to investigate the ultimate behavior, load carrying capacity of the PC girder, as well the strain behavior of the CFCC. Besides, two PC girders were placed next to the main girders of the bridge in the same conditions. One of them was used for a destructive test after six years of the construction time (1994). In this study, another test specimen that was exposed to the actual corrosive environment after nearly 30 years was subjected to a destructive test by bending load. The load carrying capacity of the girder was clarified, and the durability of the PC girders using CFCC tendon was confirmed.
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Wang, Jianqun, Shenghua Tang, Hui Zheng, Cong Zhou, and Mingqiao Zhu. "Flexural Behavior of a 30-Meter Full-Scale Simply Supported Prestressed Concrete Box Girder." Applied Sciences 10, no. 9 (April 28, 2020): 3076. http://dx.doi.org/10.3390/app10093076.
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Compared with scaled-model testing, full-scale destructive testing is more reliable since the test has no size effect and can truly record the mechanical performance of the structure. However, due to the high cost, only very few full-scale destructive tests have been conducted on the flexural behavior of prestressed concrete (PC) box girders with girders removed from decommissioned bridges. Moreover, related destructive testing on the flexural behavior of a new precast box girder has been rarely reported. To investigate the flexural behavior and optimize the design, destructive testing of a 30-meter full-scale simply supported prestressed box girder was conducted at the construction site. It is illustrated that the failure mode of the tested girder was fracture of the prestressing tendon, and the corresponding maximum compressive strain in the top flange was only 1456 μ ε , which is far less than the ultimate compressive strain (3300 μ ε ). Therefore, the concrete in the top flange was not fully utilized. A nonlinear analysis procedure was performed using the finite strip method (FSM). The validity of the analysis was demonstrated by comparing the analytical results with those of the full-scale test in the field and a scaled model test in a laboratory. Using the developed numerical method, parametric analyses of the ratio of reinforcement were carried out. The prestressing tendon of the tested girder was increased from four strands to six strands in each duct. After the optimization of the prestressed reinforcement, the girder was ductile and the bearing capacity could be increased by 44.3%.
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Zhou, Yongjun, Yu Zhao, Hengying Yao, and Yuan Jing. "Full-Scale Experimental Investigation of the Static and Dynamic Stiffness of Prestressed Concrete Girders." Shock and Vibration 2019 (December 4, 2019): 1–13. http://dx.doi.org/10.1155/2019/7646094.
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Cracking damage influences the stiffness of the girders. Many articles in the literatures have studied the development of stiffness of the scale-down model; however, full-scale model testing cannot be completely replaced by scale-down testing because of material component characteristics and boundary effects. This paper deals with the effects of cracking damage on the structural static and dynamic stiffness based on three prestressed concrete (PC) girders which were removed from an old bridge. First, the equivalent flexural rigidity of cracked prestressed concrete girder was assessed using the measured load-deflection response under cycles of loading and unloading. Then, after unloading, the frequencies were measured on the PC girders supported by the elastomeric bearings. Next, the development of frequency under different damage was studied, and finally, the dynamic stiffness of PC girders with cracks was assessed. The results indicate that the first frequency is more sensitive to the cracking of concrete compared with the second frequency and that the mode shapes are not sensitive to girder damage. The test girders cannot be simplified as an ideal simply supported beam for the purpose of identifying frequencies. In addition, the “final” (the end of the ultimate load case) equivalent flexural rigidity of the girders is 30% of the “initial” (the beginning of the first load case) equivalent flexural rigidity, compared with 50% in the scale-down test; and the final dynamic stiffness is approximately 84% of the initial dynamic stiffness, whereas the scale-down test is 72%.
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KIM, SUNG-IL, and NAM-SIK KIM. "DYNAMIC PERFORMANCES OF A RAILWAY BRIDGE UNDER MOVING TRAIN LOAD USING EXPERIMENTAL MODAL PARAMETERS." International Journal of Structural Stability and Dynamics 10, no. 01 (March 2010): 91–109. http://dx.doi.org/10.1142/s0219455410003397.
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In the design of railway bridges, it is necessary to be able to predict their dynamic behavior under a moving train load so as to avoid a resonance state from repetitive moving axle forces with uniform intervals. According to design trends, newly developed girder bridges weigh less and have longer spans. Since the dynamic interaction between bridge superstructures and passing trains is one of the critical issues concerning such railway bridges that are designed with greater flexibility, it is very important to evaluate the modal parameters of newly designed PSC girders before carrying out dynamic analyses. In this paper, a full scale incrementally prestressed 25-meter long concrete girder was fabricated as a test specimen and modal testing was performed at every prestressing stage in order to evaluate the modal parameters, including the natural frequency and the modal damping ratio. Young's modulus was also obtained from the global stiffness of the test specimen. During the modal testing, a digitally controlled vibration exciter and an impact hammer were applied in order to obtain precise frequency response functions, and the modal parameters were evaluated at various construction stages. With the availability of reliable properties from the modal experiments, dynamic performance estimation of a PSC girder railway bridge during the passage of a moving train can be carried out.
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Tang, Chenhao, Gang Zhang, Chaojie Song, Xuyang Li, and Yonggang Hou. "Flexural Behavior of Unbonded Prestressed Concrete Bridge Girders." Advances in Civil Engineering 2021 (March 30, 2021): 1–12. http://dx.doi.org/10.1155/2021/6642513.
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This paper presents an experimental and numerical investigation on the flexural behavior of unbonded prestressed concrete (PC) T bridge girders. Three unbonded PC T bridge girders with different prestress degrees spanning 3 m were selected to perform four-point bending tests and then determine the flexural performance. Flexural capacity, crack development and failure mode, load-deflection curves, strain in longitudinal rebars, and stress in prestressing strands of unbonded PC T bridge girders are experimentally analyzed. Subsequently, three-dimensional finite element (FE) models are built and validated by experiments to investigate the effect of different design parameters on flexural behavior of bridge girders. Results generated from experiment and numerical studies show that the flexural destruction behavior in unbonded PC T bridge girders experiences elastic, elastic-plastic, and ductility stages, similar to that of PC T bridge girders. The prestress degree and load location have significant influence on the destruction process in unbonded PC T bridge girders. A lower effective prestress degree can reduce the distribution range in cracks and also increase the width of cracks. Stress in prestressing strands under anchor increases rapidly after concrete presents obvious cracks, and the fracture area within prestressing strands increases with the elevation of prestress degree. The aim of this study is to provide a reference for the design and practical application of unbonded PC T bridge girders.
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Lantsoght, Eva O. L., Rutger Koekkoek, Cor van der Veen, and Henk Sliedrecht. "Fatigue Assessment of Prestressed Concrete Slab-Between-Girder Bridges." Applied Sciences 9, no. 11 (June 5, 2019): 2312. http://dx.doi.org/10.3390/app9112312.
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In the Netherlands, the assessment of existing prestressed concrete slab-between-girder bridges has revealed that the thin, transversely prestressed slabs may be critical for static and fatigue punching when evaluated using the recently introduced Eurocodes. On the other hand, compressive membrane action increases the capacity of these slabs, and it changes the failure mode from bending to punching shear. To improve the assessment of the existing prestressed slab-between-girder bridges in the Netherlands, two 1:2 scale models of an existing bridge, i.e., the Van Brienenoord Bridge, were built in the laboratory and tested monotonically, as well as under cycles of loading. The result of these experiments revealed: (1) the static strength of the decks, which showed that compressive membrane action significantly enhanced the punching capacity, and (2) the Wöhler curve of the decks, showed that the compressive membrane action remains under fatigue loading. The experimental results could then be used in the assessment of the most critical existing slab-between-girder bridges. The outcome was that the bridge had sufficient punching capacity for static and fatigue loads and, therefore, the existing slab-between-girder bridges in the Netherlands fulfilled the code requirements for static and fatigue punching.
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Su, Jia-zhan, Xi-lun Ma, Bao-chun Chen, and Khaled Sennah. "Full-scale bending test and parametric study on a 30-m span prestressed ultra-high performance concrete box girder." Advances in Structural Engineering 23, no. 7 (December 16, 2019): 1276–89. http://dx.doi.org/10.1177/1369433219894244.
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Due to its structural efficiency, durability, and cost-effectiveness, ultra-high performance concrete was utilized to build the first highway overpass bridge in China. The bridge was made of prestressed ultra-high performance concrete box girders of four continuous spans of 30 m each. As the original design of such bridge was observed to be somewhat conservative, its cross-sectional dimensions, in the form of the box girder wall thicknesses were optimized in this research to lower the material cost in future bridge construction. Then, a full-scale simply supported ultra-high performance concrete box girder of 30 m span, incorporating the new box girder wall thicknesses, was fabricated and then tested under static loading to obtain research data to justify the revised design. The loading system was designed to examine the flexural behavior of the girder using two concentrated loads symmetrically located at the mid-span. Experimental results show that the optimized girder has a favorable ductile behavior and excellent flexural strength, which can meet the design requirements for serviceability and ultimate limit states. A finite element model of the tested girder was developed, using ABAQUS software, and then was verified using the experimental findings. A parametric study was then conducted to investigate the influence of key parameters on the structural response, namely, the reinforcement ratio, the number of the prestressing wires, and the web thickness. Recommendations on minimum and maximum compressive strength and tensile property of ultra-high performance concrete were proposed. Also, a simplified calculation method of prestressed ultra-high performance concrete box girder was developed based on a verified strain and stress diagrams for cross-sectional analysis. The proposed methodology can be used in future practice with confidence.
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Tefa, Septiano H. E., Dantje A. T. Sina, and Andi Kumalawati. "Pengaruh Variasi Girder Terhadap Perilaku Struktur Atas Jembatan Beton Prategang Akibat Gempa Horizontal." JURNAL FORUM TEKNIK SIPIL (J-ForTekS) 2, no. 1 (May 28, 2022): 10–21. http://dx.doi.org/10.35508/forteks.v2i1.6624.
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Earthquakes are dangerous natural disasters and cause damage on a large scale. Therefore, this study aimed to determine the mass participation of the structure, structure capacity, and performance levels. The analysis was carried out based on the spectral response, pushover, and FEMA-356 methods. In anticipation of the damage, the design of earthquake-resistant structures has become essential in structural design, especially in the bridge structure design. The bridge samples in this study were type I prestressed concrete bridges with a length of 37 m and a width of 4 m using ten variations of girders located at the Temef Dam. The results obtained are the most critical structural conditions occur in the transverse direction. The base shear maximum capacity is more significant in the longitudinal direction than in the transversal direction. The maximum displacement capacity is higher in the transversal direction than in the longitudinal direction. The effect of cross-sectional area and cross-sectional inertia of the beam girder on the structural’s capacity is the greater the cross-sectional area and inertia of the beam girder, the greater the capacity of the structures. All of The structure performance levels were Immediate Occupancy (IO).
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Almohammedi, Ahmed, Cameron D. Murray, Canh N. Dang, and W. Micah Hale. "Investigation of measured prestress losses compared with design prestress losses in AASHTO Types II, III, IV, and VI bridge girders." PCI Journal 66, no. 3 (2021): 32–48. http://dx.doi.org/10.15554/pcij66.3-02.
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Inaccurate prediction of prestress losses leads to inaccurate predictions for camber, deflection, and concrete stresses in a bridge girder. This study aims to improve the prediction of prestress losses and provides bridge designers with insights into the differences between design and actual concrete properties. Prestress losses, compressive strength, modulus of elasticity, shrinkage, and creep were measured for several American Association of State Highway and Transportation Officials (AASHTO) Types II, III, IV, and VI girders. The investigation revealed that the measured total prestress losses at the time of deck placement were lower than the design losses calculated using the refined estimates method of the 2017 AASHTO LRFD Bridge Design Specifications. This was mainly attributed to the actual concrete compressive strength at transfer being greater than the design compressive strength. This discrepancy was as high as 73% for some girders. It was also determined that the 2017 AASHTO LRFD specifications’ refined estimates method for estimating prestress losses overestimates the total prestress losses at the time of deck placement for AASHTO Types II and III girders.
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Markosian, Nick, Raed Tawadrous, Mohammad Mastali, Robert J. Thomas, and Marc Maguire. "Performance Evaluation of a Prestressed Belitic Calcium Sulfoaluminate Cement (BCSA) Concrete Bridge Girder." Sustainability 13, no. 14 (July 14, 2021): 7875. http://dx.doi.org/10.3390/su13147875.
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Belitic calcium sulfoaluminate (BCSA) cement is a sustainable alternative to Portland cement that offers rapid setting characteristics that could accelerate throughput in precast concrete operations. BCSA cements have lower carbon footprint, embodied energy, and natural resource consumption than Portland cement. However, these benefits are not often utilized in structural members due to lack of specifications and perceived logistical challenges. This paper evaluates the performance of a full-scale precast, prestressed voided deck slab bridge girder made with BCSA cement concrete. The rapid-set properties of BCSA cement allowed the initial concrete compressive strength to reach the required 4300 psi release strength at 6.5 h after casting. Prestress losses were monitored long-term using vibrating wire strain gages cast into the concrete at the level of the prestressing strands and the data were compared to the American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) predicted prestress losses. AASHTO methods for prestress loss calculation were overestimated compared to the vibrating wire strain gage data. Material testing was performed to quantify material properties including compressive strength, tensile strength, static and dynamic elastic modulus, creep, and drying and autogenous shrinkage. The material testing results were compared to AASHTO predictions for creep and shrinkage losses. The bridge girder was tested at mid-span and at a distance of 1.25 times the depth of the beam (1.25d) from the face of the support until failure. Mid-span testing consisted of a crack reopening test to solve for the effective prestress in the girder and a flexural test until failure. The crack reopen effective prestress was compared to the AASHTO prediction and AASHTO appeared to be effective in predicting losses based on the crack reopen data. The mid-span failure was a shear failure, well predicted by AASHTO LRFD. The 1.25d test resulted in a bond failure, but nearly developed based on a moment curvature estimate indicating the AASHTO bond model was conservative.
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Siwowski, Tomasz, and Piotr Żółtowski. "Strengthening Bridges with Prestressed CFRP Strips." Selected Scientific Papers - Journal of Civil Engineering 7, no. 1 (June 1, 2012): 79–86. http://dx.doi.org/10.2478/v10299-012-0021-2.
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Abstract Limitation of bridge’s carrying bearing capacity due to aging and deterioration is a common problem faced by road administration and drivers. Rehabilitation of bridges including strengthening may be applied in order to maintain or upgrade existing bridge parameters. The case studies of strengthening of two small bridges with high modulus prestressed CFRP strips have been presented in the paper. The first one - reinforced concrete slab bridge - and the other - composite steel-concrete girder bridge - have been successfully upgraded with quite new technology. In both cases the additional CFRP reinforcement let increasing of bridge carrying capacity from 15 till 40 metric tons. The CFRP strip prestressing system named Neoxe Prestressing System (NPS), developed by multi-disciplinary team and tested at full scale in Rzeszow University of Technology, has been also described in the paper.
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Akhnoukh, Amin K. "Application of Large Prestress Strands in Precast/Prestressed Concrete Bridges." Civil Engineering Journal 6, no. 1 (January 1, 2020): 130–41. http://dx.doi.org/10.28991/cej-2020-03091458.
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The objective of this research is to investigate the advantage of using large-diameter 0.7-inch (18 mm) strands in pretention applications. Large-diameter strands are advantageous in bridge construction due to the increased girders capacity required to sustain exponential increase in vehicle numbers, sizes, and weights. In this research, flexure capacity of girders fabricated using 0.7-inch (18 mm) diameter strands will be calculated and compared to bridge capacities constructed using smaller strands. Finally, two similar bridge sections will be designed using 0.6-inch (15 mm) and 0.7-inch (18 mm) diameter strands to quantify the structural advantages of increased strand diameter. The research findings showed that a smaller number of girders is required for bridge construction when larger strands are used. Four girders are required to design the bridge panel using high performance concrete and large diameter strands, as compared to 6 girders required when regular concrete mix designs and normal size strands are used. The advantages of large strands and high-performance concrete mixes include expedited construction, reduced project dead loads, and reduced demand for labor and equipment. Thus, large strands can partially contribute to the improvement of bridge conditions, minimize construction cost, and increase construction site safety.
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Ahlborn, T. M., C. K. Shield, and C. W. French. "FULL-SCALE TESTING OF PRESTRESSED CONCRETE BRIDGE GIRDERS." Experimental Techniques 21, no. 1 (January 1997): 33–35. http://dx.doi.org/10.1111/j.1747-1567.1997.tb00490.x.
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Fam, Amir, and Dustin Brennan. "The first rolling load simulator (ROLLS) for testing bridges in Canada and its application on a full-scale precast box girder." Canadian Journal of Civil Engineering 47, no. 9 (September 2020): 1011–26. http://dx.doi.org/10.1139/cjce-2019-0341.
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This paper describes the development of a unique rolling load simulator (ROLLS) for testing bridge superstructure with a footprint up to 4 m ×17 m, and its first application to test a full-scale 1220 mm ×900 mm ×16000 mm B900 prestressed concrete box girder. This facility at Queen’s University in Kingston, Ontario, is the first of its kind in Canada. ROLLS can apply cyclic loading in a controlled laboratory environment, under realistic highway scale ‘rolling wheel loads’, in lieu of the conventional ‘pulsating stationary loads’. It has two half-axles of a large tandem, each comprising a dual 1140 mm diameter air-inflated tires spaced at either 1.2 or 2.4 m. Each half-axle can apply up to 125 kN, representing the heaviest half-axle load of the CL-625 design truck of the Canadian Highway Bridge Design Code (CHBDC). The maximum travel range and speed are 14.9 m and 6 m/s, respectively. A case study involving analysis of a bridge with eight adjacent B900 box girders of 27.6 m span was carried out prior to experimentally testing one of the girders using ROLLS. Load distribution analyses were conducted using both (i) a finite element model of the full bridge under various CL-625 truck loading configurations and (ii) the CHBDC load distribution method, and both agreed well. Scaling analysis of the girder load share was then conducted to account for shortening it to 16 m to fit in the laboratory, resulting in two-115 kN ROLLS design loads, 1.2 m apart. Multiple passes were conducted at various loads of 40%–100% of the design load, at speeds of 1–5 m/s to examine the machine and girder behaviours. It was found that the applied load fluctuates by less than 10% of full capacity and a 0.13 s/cycle time lag occurs. The measured girder deflection and elastic strains were 11%–20% lower than predicted theoretically. With the two half-axles assembly spaced at 1.2 m, the apparatus has the ability to complete three million cycles in approximately 4.5 months if ran continuously at 5 m/s.
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Savino, Pierclaudio, Francesco Tondolo, Donato Sabia, Antonino Quattrone, Fabio Biondini, Gianpaolo Rosati, Mattia Anghileri, and Bernardino Chiaia. "Large-Scale Experimental Static Testing on 50-Year-Old Prestressed Concrete Bridge Girders." Applied Sciences 13, no. 2 (January 7, 2023): 834. http://dx.doi.org/10.3390/app13020834.
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The heritage of existing road infrastructures and in particular of bridges consists of structures that are approaching or exceeding their designed service life. Detrimental causes such as aging, fatigue and deterioration processes other than variation in loading conditions introduce uncertainties that make structural assessment a challenging task. Experimental data on their performances are crucial for a proper calibration of numerical models able to predict their behavior and life-cycle structural performance. In this scenario, an experimental research program was established with the aim of investigating a set of 50-year-old prestressed concrete bridge girders that were recovered from a decommissioned bridge. The activities included initial non-destructive tests, and then full-scale load tests followed by a destructive test on the material samples. This paper reports the experimental results of the full-scale tests conducted on the first group of four I-beams assumed to be in good condition from visual inspection at the time of testing. Loading tests were performed using a specifically designed steel reaction frame and a test setup equipment, as detailed in the present work. Due to the structural response of this first group of girders, a uniform behavior was found at both service and ultimate conditions. The failure mechanism was characterized by the crushing of the cast-in-situ top slab corresponding to a limited deflection, highlighting a non-ductile behavior. The outcomes of the experimental research are expected to provide new data for the life-cycle safety assessment of existing bridges through an extended database of validated experimental tests and models.
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Li, Fan, Rong Xia Wang, Shun Wei Chen, and Jian Bin Zhou. "Structural Characteristics of FRP-Concrete Bridge Deck System." Applied Mechanics and Materials 178-181 (May 2012): 2369–72. http://dx.doi.org/10.4028/www.scientific.net/amm.178-181.2369.
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This paper describes the structural forms for hybrid FRP-concrete highway bridge deck. This bridge deck is applid in a project, which involved the implement of FRP-concrete deck over prestress concrete girders. In this project three forms of FRP reinforcing were combined to reinforce the concrete deck. This paper introduced another stiffened FRP deck panels connecte with the FRP composite girders in the steel-free FRP-composite modular bridge system. It is shown that the combination of FRP meterial and concrete for bridge deck is recommended in the design of highway bridge.
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Stallings, I. MichaelI, Robert W. Barnes, and Sam Eskildsen. "Camber and Prestress Losses in Alabama HPC Bridge Girders." PCI Journal 48, no. 5 (September 1, 2003): 90–104. http://dx.doi.org/10.15554/pcij.09012003.90.104.
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Huo, Xiaoming (Sharon), and Maher K. Tadros. "Structural Design of High-Performance Concrete Bridge Beams." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 171–78. http://dx.doi.org/10.3141/1696-59.
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Recently high-performance concrete (HPC) has been used in highway bridges and has gained popularity for its short-term and prospective long-term performances. Benefits of using HPC include fewer girder lines required, longer span capacity of girders, reduced creep and shrinkage deformation, less prestress losses, longer life cycle, and less maintenance of bridges. Research has been conducted on several issues of structural design of HPC bridge beams. The topics discussed include the effects of section properties of prestressed concrete girders, allowable tensile and compressive stresses, creep and shrinkage deformations of HPC, and prediction of prestress losses with HPC. The results from a parametric study have shown that a section that can have a large number of strands placed in its bottom flange is more suitable for HPC applications. The use of 15-mm-diameter prestressing strands allows the higher prestressing force applied on sections and can provide more efficiency in HPC bridges. The research results also indicate that the allowable compressive strength of HPC has a major effect on the structural design of bridges, whereas the allowable tensile stress has a minor effect on the design. Equations for predicting prestress losses based on the experimental and analytical results are recommended. The recommended equations consider the effects of lower creep and shrinkage deformations of HPC.
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Yang, Yumin, and John J. Myers. "Prestress Loss Measurements in Missouri's First Fully Instrumented High-Performance Concrete Bridge." Transportation Research Record: Journal of the Transportation Research Board 1928, no. 1 (January 2005): 118–25. http://dx.doi.org/10.1177/0361198105192800113.
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Prestress losses have a direct impact on concrete stress development and deflection behavior of highway bridge members. A poor estimate of prestress losses can result in a structure in which allowable stresses are exceeded or camber and deflection behavior is poorly predicted, such that the serviceability of a structure may be adversely affected. This paper reports the prestress losses observed throughout fabrication, shipment, erection, and the first 2 years of service for the first high-performance superstructure concrete bridge in Missouri. The prestress losses investigated included prerelease losses, elastic shortening losses, relaxation losses, creep losses, and shrinkage losses. Results from the study were compared with eight commonly used loss estimate models for total prestress losses, including AASHTO and Prestressed Concrete Institute methods. Recommendations were proposed by the authors for the most appropriate methodology to use to predict prestress losses in high-strength concrete girders accurately.
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Hao, Chaowei, Yanjiang Chen, Yu Tang, and Laiyong Wang. "Mechanical Properties of Full-Scale Prestressed Concrete Beams with Thin Slab after Exposure to Actual Fire." Advances in Materials Science and Engineering 2021 (December 10, 2021): 1–13. http://dx.doi.org/10.1155/2021/2211413.
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To provide an effective basis and reference for applications of prestressed concrete thin-slab beams after a bridge fire, methods and principles of fire-resistant design, repair, and reinforcement of such beams were discussed. Taking a simple supported and continuous girder bridge of an expressway in service as a sample, appearance testing and nondestructive testing of the internal structure were carried out. Four representative full-scale prestressed concrete beams were selected. Through the comparative test of the ultimate bearing capacity of such beams, the laws of the deflection deformation, strain distribution, crack formation, and crack development were obtained. By combining with the finite element simulation and theoretical analysis, the ultimate bearing capacity, complex mechanical characteristics, and breakage feature and failure mechanism of such beams were studied. It was indicated by the results the following: (1) Prestress loss will cause height reduction of the concrete shear zone, which is one of the main reasons why the bending-shearing failure of such beams happened before the pure bending failure. (2) Under certain operating loads, brittle fracture is more likely to occur on the bottom surface of such beams when directly exposed to fire. (3) The bursting and spalling depth of concrete after being exposed to fire can be used as the characteristic parameters for the rapid identification of the bottom surface of such after-fire beams.
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Chai, Shun, Tong Guo, Zheheng Chen, and Jun Yang. "Flexural Behavior of Precast Concrete Segmental Box-Girders with Dry Joints." Advances in Civil Engineering 2020 (November 5, 2020): 1–14. http://dx.doi.org/10.1155/2020/8895180.
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Precast concrete segmental (PCS) box-girders are widely used in bridge construction, while studies on flexural behaviors of PSC box-girders with dry joints are insufficient. Six large-scale PCS box-girders with dry joints were tested to failure under two-point loading in this study. Strain increments, tendon forces, deflections at mid-span, and cracks were recorded during the tests. Multiple factors were investigated with regards to their influence on flexural performance of girders. It is found that most specimens failed due to the excessive force in tendons, while the specimen with external tendons failed due to concrete compressive crushing. Larger shear span ratio resulted in greater increase in tendon force and concrete strain during loading and, accordingly, the lowest ultimate flexural capacity. Lower concrete strength resulted in larger increase in concrete strain and tendon force during loading and relatively smaller deflection at failure. For the specimen with four segments, a significant increase in tendon force and smaller deflections at failure was observed as compared with specimen 1, though the failure load was similar. Numerical simulation is further conducted, where it is found that the area of prestressed tendon and the number of joints have a significant influence on ultimate flexural bearing capacity and deflection; besides, deflection control standard of PCS girders should be stricter than that of the integral cast girder. The corbel joints, in general, show better ultimate performance than the castle-shaped joints.
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Kahn, Lawrence F., and Mauricio Lopez. "Prestress Losses in High Performance Lightweight Concrete Pretensioned Bridge Girders." PCI Journal 50, no. 5 (September 1, 2005): 84–94. http://dx.doi.org/10.15554/pcij.09012005.84.94.
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Bonopera, Marco, Kuo-Chun Chang, and Zheng-Kuan Lee. "State-of-the-Art Review on Determining Prestress Losses in Prestressed Concrete Girders." Applied Sciences 10, no. 20 (October 16, 2020): 7257. http://dx.doi.org/10.3390/app10207257.
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Prestressing methods were used to realize long-span bridges in the last few decades. For their predictive maintenance, devices and dynamic nondestructive procedures for identifying prestress losses were mainly developed since serviceability and safety of Prestressed Concrete (PC) girders depend on the effective state of prestressing. In fact, substantial long term prestress losses can induce excessive deflections and cracking in large span PC bridge girders. However, old unsolved problematics as well as new challenges exist since a variation in prestress force does not significantly affect the vibration responses of such PC girders. As a result, this makes uncertain the use of natural frequencies as appropriate parameters for prestress loss determinations. Thus, amongst emerging techniques, static identification based on vertical deflections has preliminary proved to be a reliable method with the goal to become a dominant approach in the near future. In fact, measured vertical deflections take accurately and instantaneously into account the changes of structural geometry of PC girders due to prestressing losses on the equilibrium conditions, in turn caused by the combined effects of tendon relaxation, concrete creep and shrinkage, and parameters of real environment as, e.g., temperature and relative humidity. Given the current state of quantitative and principled methodologies, this paper represents a state-of-the-art review of some important research works on determining prestress losses conducted worldwide. The attention is principally focused on a static nondestructive method, and a comparison with dynamic ones is elaborated. Comments and recommendations are made at proper places, while concluding remarks including future studies and field developments are mentioned at the end of the paper.
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Yan, Liang. "Load Test Analysis of a Long-Span Prestressed Nano-Concrete Highway Bridge." International Journal of Analytical Chemistry 2022 (September 30, 2022): 1–7. http://dx.doi.org/10.1155/2022/5169548.
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In order to solve the problem of vehicle-bridge coupling vibration of a continuous semisteel bridge, the main bridge type of long-span prestressed concrete girder bridge, the author proposes a bridge safety test system based on the dynamic and static load test. The system combines the change of stress and deflection with the vibration amplitude of the bridge body, and using the modeling assistant in large-scale finite element software MIDAS/CIVIL, a three-dimensional finite element real bridge model is established, including input of section data, the input of boundary conditions, and the input of loads. The result obtained is as follows: the structural verification coefficient of the control strain of the main girder under each working condition is not greater than 1.0, indicating that the flexural rigidity of the structure meets the design requirements. In addition, under each working condition, the ratio of the residual strain after unloading to the measured total strain is less than 20%. Under each working condition, the deflection calibration coefficient of each control section is less than 1.0, and the ratio of residual deflection to total deflection of each measuring point is at most 3.9%; each residual deflection is small. The damping ratios are all less than 5% of the empirical damping ratio of concrete members, indicating that the bridge structure is in good condition. The result obtained by the author is compared with the standard allowable value and the theoretical calculation value, so as to provide a basis for the study of the bearing capacity of similar bridges and to verify the standardization and rationality of the existing bridge structural design.
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Kim, Sung Tae, Hyejin Yoon, Young-Hwan Park, Seung-Seop Jin, Soobong Shin, and Suk-Min Yoon. "Smart Sensing of PSC Girders Using a PC Strand with a Built-in Optical Fiber Sensor." Applied Sciences 11, no. 1 (January 1, 2021): 359. http://dx.doi.org/10.3390/app11010359.
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This paper presents a multi-functional strand capable of introducing prestressing force in prestressed concrete (PSC) girders and sensing their static and dynamic behavior as well. This innovative strand is developed by replacing the core steel wire of the strand used in PSC structures with a carbon fiber-reinforced polymer (CFRP) wire with a built-in optical Fiber Bragg Grating (FBG) sensor. A full-scale girder specimen was fabricated by applying this multi-function strand to check the possibility of tracking the change of prestressing force at each construction stage. Moreover, dynamic data could be secured during dynamic loading tests without installing accelerometers and made it possible to obtain the natural frequencies of the structure. The results verified the capability to effectively manage the prestressing force in the PSC bridge structure by applying the PC strand with a built-in optical sensor known for its outstanding practicability and durability.
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Civjan, Scott A., James O. Jirsa, Ramon l. Carrasquillo, and David W. Fowler. "Instrument to Evaluate Remaining Prestress in Damaged Prestressed Concrete Bridge Girders." PCI Journal 43, no. 2 (March 1, 1998): 62–71. http://dx.doi.org/10.15554/pcij.03011998.62.71.
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Breen, John E., Michael E. Kreger, Christopher D. White, and Gordon C. Clark. "Field evaluation and model test of a composite wing-girder bridge." Canadian Journal of Civil Engineering 14, no. 6 (December 1, 1987): 753–62. http://dx.doi.org/10.1139/l87-113.
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This paper presents the key observations and conclusions from the evaluation of an innovative "loose-fit" composite, post-tensioned concrete wing-girder bridge proposed for an elevated interstate highway expansion in an urban environment. The evaluation program included both testing to destruction of a 1/2-scale model of a partial span as well as construction monitoring and field testing at service load levels of a full-scale prototype two-span bridge. Results of both construction measurements and loading tests were compared with analytical predictions. Laboratory tests showed the composite behavior of the wing-girder joint to be fully effective and a high level of load transfer between wings to be present. Recommendations for modification of the prototype design are made to improve constructibility, durability, structural performance, and economy. Key words: box girder, bridge, post-tensioned, prestressed concrete, reinforcement, stresses, temperature, tendons.
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Osborn, G. Parry, Paul J. Barr, David A. Petty, Marvin W. Halling, and Travis R. Brackus. "Residual Prestress Forces and Shear Capacity of Salvaged Prestressed Concrete Bridge Girders." Journal of Bridge Engineering 17, no. 2 (March 2012): 302–9. http://dx.doi.org/10.1061/(asce)be.1943-5592.0000212.
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Carlin, G. P., M. S. Mirza, and M. Gaudreault. "Rehabilitation measures for Champlain Bridge, Montreal, Canada." Canadian Journal of Civil Engineering 23, no. 6 (December 1, 1996): 1326–40. http://dx.doi.org/10.1139/l96-941.
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Major rehabilitation of the Champlain Bridge, Montreal, Quebec, has been undertaken with the goal of restoring its overall integrity. The bridge is a major transportation link carrying over 42 million vehicle transits annually. Repairs to all elements of the structure have recently been under way, such as deck replacement, pier repairs including submerged regions, restoration to prestressed girders, implementation of cathodic protection to control corrosion, new drainage provisions, and crash barriers. Rehabilitation of the main steel truss spans over the St. Lawrence Seaway is presented elsewhere. Testing of two cathodic protection systems on prestressed concrete beams has been undertaken with the goal of full-scale installation on all 50 affected spans. A possible pilot project is being examined, which incorporates the use of zinc anode spray applied to the concrete surface to act as passive, or induced current type, or as a combination of active and passive systems on the different sections of the bridge. Key words: bridge rehabilitation, cathodic protection systems, condition survey, corrosion protection strategy, external prestressing, honeycombing and spalling, impervious membrane, injection of cracks, prestressed concrete beams, underwater pier repairs.
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Harrison, Alex, and N. David LeBlanc. "Design and Construction of a Full-Width, Full-Depth Precast Concrete Deck Slab on Steel Girder Bridge." Transportation Research Record: Journal of the Transportation Research Board 1907, no. 1 (January 2005): 54–66. http://dx.doi.org/10.1177/0361198105190700107.
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The West Sandusky Street Bridge over I-75 in Findlay, Ohio, consisted of a single 170-ft-span hybrid steel plate girder bridge with a concrete deck. To minimize closure times on West Sandusky Street and reduce traffic delays on I-75 during the bridge's replacement, full-width, full-depth precast concrete deck panels were proposed for the bridge deck construction. The precast deck panels are posttensioned both longitudinally and transversely to minimize cracking and improve durability and are constructed with shear stud pockets to allow for the installation of shear studs after erection and posttensioning. During detail design, a finite element analysis of the bridge deck was carried out to determine the required level of prestress in the deck. A time-dependent analysis was subsequently completed to determine the long-term creep effects and posttensioning losses, including the effects of restraint from the steel girders. A sensitivity analysis determined the optimum curing time required before stressing the longitudinal posttensioning tendons and grouting the shear pockets. The steel plate girders were designed for the long-term creep effects due to the posttensioning of the deck, which imposed additional axial loads and moments on the steel girders. The replacement deck panels were fabricated before bridge demolition and road closure. Bridge construction was completed in fall 2004.
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Razaqpur, A. G., Mostafa Nofal, and M. S. Mirza. "Nonlinear analysis of prestressed concrete box girder bridges under flexure." Canadian Journal of Civil Engineering 16, no. 6 (December 1, 1989): 845–53. http://dx.doi.org/10.1139/l89-127.
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One-seventh scale direct models of single-cell and two-cell prestressed concrete box girder bridges, tested to destruction at McGill University, are analyzed by the nonlinear finite element technique. The nonlinear program NONLACS, utilized in the analysis, is described in detail together with the material models employed. The objective of the current study is to demonstrate the capabilities of the finite element program NONLACS in predicting the ultimate strength and complete response of prestressed concrete box girder bridges at all stages of loading up to the ultimate load. The load–deflection curves, concrete and steel stresses, and deflected shapes of the bridges at different load levels are compared with the corresponding experimental data. The results verify the applicability of the nonlinear finite element method as an economical and expedient alternative, in some cases, to expensive experimental work aimed at the investigation of the complete response of complex structures to applied loads. Key words: box girder bridges, concrete, concrete and steel strains, experimental data, finite element, load–deflection characteristics, nonlinear analysis, prestressing.
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Jagandatta, M., G. Yaswanth Kumar, and S. Suresh Kumar. "Analysis and Design of Composite Single Span Psc-I Girder Bridge Using Midas Civil." IOP Conference Series: Earth and Environmental Science 982, no. 1 (March 1, 2022): 012078. http://dx.doi.org/10.1088/1755-1315/982/1/012078.
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Abstract With the ever-increasing sophistication of the population and the usage of vehicles, the number of modern road and bridge construction projects in India is increasing. To facilitate traffic flow, composite bridges are increasingly being implemented on a wide scale for highway building. In addition, new technology and equipment were gradually applied to road and bridge building. But, at the same time, there are several flaws in the structures due to the high technical requirements of bridge building, particularly the composite type of sections. The paper discusses the analysis and design of the Composite Single Span PSC-I Girder Bridge under IRC loadings using MIDAS. The analysis was carried out to get various outputs such as bending moment, shear force, and time-dependent characteristics like creep and shrinkage. At the construction stage, the PSC (prestressed) design of the span is carried out according to IRC standards to get output parameters such as principal stresses for prestressing tendon. The design involves calculation of the section properties, primary and secondary moments, magnitude and location of the prestressing force, profile of the tendons, losses due to prestressing and shear stresses on the section. The structure is designed in accordance with IRC guidelines.
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Staśkiewicz, Michał, Renata Kotynia, Julien Michels, Christoph Czaderski, and Masoud Motavalli. "Experimental tests of post-tensioned girders strengthened with prestressed CFRP composites." Budownictwo i Architektura 13, no. 3 (September 11, 2014): 159–66. http://dx.doi.org/10.35784/bud-arch.1812.
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The paper presents a research carried out within the framework of the Polish-Swiss “Tulcoempa” project, carried out by Lodz University of Technology and EMPA Swiss Federal Laboratories for Materials Science and Technology. The main goal of the project was to perform the first field application of an innovative, anchorless flexural strengthening with use of prestressed CFRP laminates on an existing bridge in Poland. Laboratory tests were conducted to verify the efficiency of the strengthening of two real-scale, 18.4m long, post-tensioned bridge girders reconstructed at EMPA institute. Flexural strengthening was successful and resulted in an increase of the member’s load capacity by 24% and reduction of the midspan deflection by more than 60%.
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Wu, Wen Qing, Shuai Chen, and Xue Yuan Ma. "Investigation on Duct Grouting Quality of PC Continuous Box Girders." Applied Mechanics and Materials 94-96 (September 2011): 2204–8. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.2204.
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Based on three bridge dismantlement, duct grouting density of prestressing tendons was investigated in-situ . The indices were analyzed statistically to find out the construction quality of PC box-girders in China. The investigation result indicated that the duct of prestressing tendons were only partially grouted, with over 50% ungrouted for longitudinal tendons and over 70% ungrouted for transverse tendons. Obviously, this increased the prestress loss in the tendons. The quantitative indices proposed in the paper is helpful in understanding the underlying reason for cracking and over flexing in the PC box girder ,and it also provided the important basis for structural analysis of PC box-girders.
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Kim, Sang-Hyun, Sung Yong Park, and Se-Jin Jeon. "Long-Term Characteristics of Prestressing Force in Post-Tensioned Structures Measured Using Smart Strands." Applied Sciences 10, no. 12 (June 13, 2020): 4084. http://dx.doi.org/10.3390/app10124084.
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The proper distribution of prestressing force (PF) is the basis for the design of prestressed concrete (PSC) structures. However, the PF distribution obtained by predictive equations of prestress losses has not been sufficiently validated by comparison with measured data due to the poor reliability and durability of conventional sensing technologies. Therefore, the Smart Strand with embedded fiber optic sensors was developed and applied to PSC structures to investigate the long-term characteristics of PF distribution as affected by concrete creep and shrinkage. The data measured in a 20 m-long full-scale specimen and a 60 m-long PSC girder bridge were analyzed by comparing them with the theoretical estimation obtained from several design equations. Although the long-term decreasing trend of the PF distribution was similar in the measurement and theory, the equation of Eurocode 2 for estimating the long-term prestress losses showed better agreement with the measurement than ACI 209R and ACI 423.10R did. This can be attributed to the more refined form of the predictive equation of Eurocode 2 in dealing with the time-dependency of the PF. The study results also confirmed the need to compensate for the temperature variation in the long-term monitoring to derive the actual mechanical strain related to the PF. We expect our developed Smart Strand to be applied practically in PF measurement for the reasonable safety assessment and maintenance of PSC structures by improving several of the existing drawbacks of conventional sensors.
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Yoon, Hyejin, Sung Tae Kim, Won Jong Chin, Young Jin Kim, and Jeong-Rae Cho. "Dynamic Performance of a New-Type PSC I-girder for Railway Bridge Application." Applied Sciences 10, no. 23 (December 5, 2020): 8728. http://dx.doi.org/10.3390/app10238728.
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This study intends to verify analytically and experimentally the performance of a new type of prestressed concrete (PSC) I-girder for its application as railway bridge. Since the girder-type railway bridge develops relatively low torsional rigidity, there is risk for the dynamic responses to amplify due to the superposition of the torsional mode and flexural mode. The superposition of the torsional and flexural modes as well as the dynamic stability of the railway bridge were examined through dynamic analysis. Three-dimensional modelling was built to be suitable for carrying out moving load analysis. Four different span lengths of 30, 35, 40 and 45 m adopted considering the most applied span length currently and future lengthening of the span length. Moreover, a full-scale girder specimen with span length of 35 m was fabricated and subjected to dynamic loading. The measured dynamic responses were then compared to the analytic values. Finally, the ultimate bearing capacity of the specimen was verified by static loading test.
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Guo, Fan, Yong Qing Yang, and Sheng Qian Huang. "Research on Deflection and Cracking of Prestressed Concrete Continuous Girder Bridge." Advanced Materials Research 838-841 (November 2013): 1014–17. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.1014.
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Through the checking comparison of example bridge, to analysis the major causes of the cracking and too much deflection for prestressed concrete continuous box girder bridge. Calculated weak position and the current presence of cracks in the bridge position basically consistent, so cracks mainly caused by the prestress loss, concrete creep and the temperature effect, the structure stiffness weakened after cracking, then the actual mid-span deflection is greater than the calculated values bound. Therefore, the cracking and too much deflection appear simultaneous and mutual promote. The view that by improving the mechanical behavior of box girders, design parameters optimization, just the fundamental solution to cracking and too much deflection, also, several key issues need study to be addressed.
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Paul, Alistair. "Large and Small Incrementally Launched Structures." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 122–30. http://dx.doi.org/10.3141/1696-15.
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The technology for incrementally launched structures has been known for several decades. It had not been utilized in South Australia until a recent flurry of activity revealed that this method could be economically utilized for both small and large structures. Within 3 years, four structures of various sizes were constructed using the technique. A double-T prestressed concrete recreational jetty was incrementally launched at one of Adelaide’s suburban beaches (Brighton Jetty). Twin single-cell prestressed concrete (PSC) box girders were incrementally launched over eight lanes of traffic at a busy signalized suburban road intersection without disruption to traffic (bridge over Port Wakefield Road). Two incrementally launched major bridges were constructed over the River Murray, Australia’s longest river. The first structure consisted of steel girders composite with a reinforced concrete deck (Berri Bridge, 330 m long), and the other structure was a single PSC box girder (Blanchetown Bridge, 410 m long). All these structures are mentioned, but the focus is on the PSC box girder structures. Construction problems associated with the use of permanent bearings as launch bearings and the sensitivity of box girders to construction tolerances are discussed, and the lessons to be learned are presented. Finally, an unsuccessful attempt to monitor the long-term prestress of the Blanchetown Bridge using state-of-the-art optical fiber technology is discussed, including the reasons for its failure and possible improved future methodology.
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Lin, Yi-Ching, Chin-Yu Hsiao, Jian-Hua Tong, Chih-Pin Liao, Shin-Tai Song, Hsin-Chu Tsai, and Jui-Lin Wang. "Application of Edge Computing in Structural Health Monitoring of Simply Supported PCI Girder Bridges." Sensors 22, no. 22 (November 11, 2022): 8711. http://dx.doi.org/10.3390/s22228711.
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This study proposes an innovative method for structural health monitoring of simply supported PCI girder bridges based on dynamic strain and edge computing. Field static and dynamic load tests were conducted on a bridge consisting of a span with newly replaced PCI girders and numerous spans with old PCI girders. Both the static and dynamic test results showed that the flexural rigidity of the old PCI girders decreased significantly due to deterioration. To improve the efficiency of on-site monitoring data transmission and data analysis, this study developed a smart dynamic strain gauge node with the function of edge computing. Continuous data with a sampling frequency of 100 Hz were computed at the sensor node. Among the computed results, only the maximum dynamic strain data caused by the passage of the heaviest vehicle within 1 min were transmitted. The on-site monitoring results indicated that under routine traffic conditions, the dynamic strain response of the new PCI girder was smaller than that of the deteriorated PCI girder. When the monitored dynamic strain response has a tendency to magnify, attention should be paid to the potential prestress loss or other deterioration behaviors of the bridge.
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Jiang, Xin, Xinlin Ban, Lin Ma, Yonghua Su, Qi Cao, Zhouyu Zhang, and Jichao Guo. "Prestressed Concrete Box Girder with High-Capacity Strands-Monitoring and Analysis during Fabrication." Buildings 12, no. 7 (June 28, 2022): 911. http://dx.doi.org/10.3390/buildings12070911.
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Despite the attractive merits of high-capacity strands, the application in bridge girders is limited due to concerns, including concrete cracking, excessive stress, and cambers. An efficient and defect-free production is the first step to wide application. The objective of this research was to alleviate the production concerns of prestressed concrete bridge girders using high-capacity strands. A gigantic prestressed concrete box girder using 18-mm strands was produced; its entire fabrication process (from strand stressing to detension) was introduced. Sixteen temperature gauges were embedded in the girder to monitor the hydration of the large volume of concrete and the adjacent environmental temperature. Moreover, displacement transducers were used to measure the camber at detension; load cells were installed to monitor the variations of the prestressing strand tensile forces during fabrication. Monitoring and analysis showed that the timing of the detension is determined by the hydration of the concrete, the compressive strength of the concrete, and its modulus of elasticity or age. Since the tensile forces in strands are affected by the concrete’s internal temperature, the detension is conducted after the concrete temperature falls back (close to its initial value); otherwise, unfavorable and considerable prestress losses are caused. Finally, a 4-d detension was suggested since the hydration was not a concern at the time; the predicted prestress loss and camber were acceptable and the concrete material properties at 4 d satisfied the requirements.
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Singh, Brahama P., Nur Yazdani, and Guillermo Ramirez. "Effect of a Time Dependent Concrete Modulus of Elasticity on Prestress Losses in Bridge Girders." International Journal of Concrete Structures and Materials 7, no. 3 (September 2013): 183–91. http://dx.doi.org/10.1007/s40069-013-0037-0.
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Murray, Cameron D., Mauricio Diaz Arancibia, Pinar Okumus, and Royce W. Floyd. "Destructive testing and computer modeling of a scale prestressed concrete I-girder bridge." Engineering Structures 183 (March 2019): 195–205. http://dx.doi.org/10.1016/j.engstruct.2019.01.018.
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Guo, Tong, Wen Hai Chen, and Yong Sheng Song. "Bending Capacity of Reinforced Concrete Box-Girders Strengthened with SMPM Laminates." Advanced Materials Research 368-373 (October 2011): 2235–40. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.2235.
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Steel stranded wire mesh and polymer mortar (SMPM) is a novel technique recently developed for structural strengthening. To investigate the feasibility of strengthening reinforced concrete (RC) bridge box-girders with SMPM, bending tests on three scaled RC box-girders were made, based on which formulas for predicting the bending and debonding capacities of the strengthened RC box-girders are proposed. First, the box section is represented by the T section using the effective width factor in the elastoplastic stage. Then, based on the equivalent height of compressive region, bending failure modes of the strengthened girders are classified, and equations regarding the ultimate bending capacity corresponding to each failure mode are established respectively. To account for the debonding failure observed in the tests, a shear-capacity-based model is proposed. Comparison was made between the analytical and existing test results.
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Roller, John J., Henry G. Russell, Robert N. Bruce, and Walid R. Alaywan. "Evaluation of prestress losses in high-strength concrete bulb-tee girders for the Rigolets Pass Bridge." PCI Journal 56, no. 1 (January 1, 2011): 110–34. http://dx.doi.org/10.15554/pcij.01012011.110.134.
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