Journal articles: 'Partial Prestressing'

1

Wang, Zuohu, Zhanguang Gao, Yuan Yao, and Weizhang Liao. "Experimental investigation on the seismic behavior of concrete beams with prestressing carbon fiber reinforced polymer tendons." Science Progress 103, no. 1 (November 1, 2019): 003685041988523. http://dx.doi.org/10.1177/0036850419885235.

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Seven prestressed concrete beams and one normal concrete beam were tested to study the seismic performance of concrete beams with prestressing carbon fiber reinforced polymer tendons. The failure modes, hysteretic curves, ductility, stiffness degeneration, and energy dissipation capacity were studied systematically. This study shows that the partial prestressing ratio is the main factor that affects the seismic performance of carbon fiber reinforced polymer prestressed concrete beams. The beam is more resilient to seismic loads as the partial prestressing ratio decreases. Under the same partial prestressing ratio value, the energy dissipation capacity of prestressed concrete beams with unbonded carbon fiber reinforced polymer tendons was better than that of prestressed beams with bonded carbon fiber reinforced polymer tendons. When combining both bonded and unbonded prestressing carbon fiber reinforced polymer tendons, the ductility index of concrete beams was improved. Compared with that of fully unbonded and fully bonded carbon fiber reinforced polymer prestressed concrete beams, the ductility index of concrete beams with combined bonded and unbonded prestressing tendons increased by 26% and 12%, respectively.

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Khuranov, Valery, Aslan Kaziev, Akhmed Shogenov, and Azamat Balov. "Partial prestressing as a method of equal-strength structures bending approaching." E3S Web of Conferences 281 (2021): 01012. http://dx.doi.org/10.1051/e3sconf/202128101012.

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The use of partial prestressing as a way to save materials in building structures is observed in the article. The redesign of a typical prestressed reinforced concrete rafter beam with a span of 12 m with parallel belts, in which partial prestressing was applied, made it possible to reduce the main working high-tensile reinforcement consumption by more than 30% and increase the high-tensile reinforcement using efficiency from 0.58 to 0.74.

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Yin, Zhi Xiang, Li Min Tian, and Zhe Gao. "Study on Stability of a New Prestressed SINGLE-Layar Spherical Lattice Shell." Advanced Materials Research 163-167 (December 2010): 2157–61. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2157.

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Prestressing of lattice shell is realized by cable, and author put forward a new kind of layout: The prestressing has been brought to bear by hoop and radial element of single-layer lattice shell, which avoid cable's effect on architectural purpose. The element has been made to sleeve, and the magnitude of prestressing is dominated by bolt. Article shows an example of K6, K8 single-layer spherical lattice shell, and the prestressing have been exert on partial ribs and hoops. The prestressing has been calculated by element axial force under normal loading. Stability of shells have been studied, and show the deformation satisfy the criteria under normal loading; The ultimate capacity has been improved obviously, loads transfer is rational. The new layout of prestressing is a promising technique.

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Limsuwan, Ekasit, Suchart Chayochaichana, and Uthai Lerksirirat. "Partial Prestressing of Long Span Steel Truss Girder." IABSE Symposium Report 101, no. 6 (September 1, 2013): 1–4. http://dx.doi.org/10.2749/222137813808627604.

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5

Batchelor, B. deV, and Jayanth Srinivasan. "Calculation of stress in prestressing steel at ultimate conditions." Canadian Journal of Civil Engineering 16, no. 4 (August 1, 1989): 576–82. http://dx.doi.org/10.1139/l89-088.

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This paper reviews different methods available for the calculation of stress in prestressing steel at ultimate, ƒps, and the methods are evaluated using a nonlinear analysis computer program. The development of a nonlinear model for the analysis of partially prestressed concrete flexural members is described. The model takes the material nonlinearities into account by the use of appropriate stress–strain relationships for steel and concrete. A parametric study of partially prestressed beams was conducted to study the effect of various parameters on stress in prestressing steel at ultimate conditions. Two types of sections, rectangular and T sections, were studied. The prediction equation, recommended in the Canadian Code Can3-A23.3-M84, for calculating the stress in prestressing steel at ultimate is found to be very conservative for all the cases studied, which covered all possible ranges of partial prestressing ratio. The present restriction in the Canadian Code, for the use of their prediction equation only when the ratio of the neutral axis depth, Cu, to the depth of the centroid of prestressing steel, dps, is less than or equal to 0.3, is found to be too restrictive. An alternative equation for ƒps, suggested by Loov, is found to be more suitable than the present equation in the Canadian Code; however, a more practical upper limit for cu/dps ratio is suggested in the paper. It is shown that the proposed equation can be used conservatively over the complete range of partially prestressed concrete. Key words: analysis, concrete (prestress), flexure, partial prestressing, prestressing, strain, stress, steel.

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Ronghe, G. N., and L. M. Gupta. "Parametric Study of Tendon Profiles in Prestressed Steel Plate Girder." Advances in Structural Engineering 5, no. 2 (April 2002): 75–85. http://dx.doi.org/10.1260/1369433021502579.

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The concept of prestressing steel structures has only recently been widely considered, despite a long and successful history of prestressing concrete members. Several analytical studies of prestressed steel plate girder were reported in the literature, but much of that work was not studied with reference to different parameters like tendon profile, eccentricity, partial span to full span ratio, prestressing force, load carrying capacity etc. associated with prestressing. This paper examines analytically a comparative study of various tendon configurations and prestressing parameters on over all analysis and design of prestressed steel plate girder. The output from the computer Program for analysis and design of steel plate girder prestressed with different tendon configurations are compared among each other. As a Case-study, a prototype model of Prestressed Steel Testing Frame with straight tendon has been designed, constructed and tested in the laboratory for its safe load carrying capacity and maximum deflection.

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Batchelor, B. DeV, Jayanth Srinivasan, and Mark F. Green. "Losses in partially prestressed concrete." Canadian Journal of Civil Engineering 15, no. 5 (October 1, 1988): 890–99. http://dx.doi.org/10.1139/l88-114.

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The calculation of prestress losses by the age-adjusted effective modulus method is analyzed and compared with the Ontario highway bridge design code predictions for partially prestressed concrete. Specifically, the effect of nonprestressed reinforcement on prestress losses is studied. The age-adjusted effective modulus method for calculating prestress losses is outlined, and plots of prestress losses versus partial prestressing ratio are presented and analyzed. It is shown that prestress losses decrease with increasing amounts of nonprestressed reinforcement. Also, the Ontario highway bridge design code expressions, which are intended for use with fully prestressed sections, are not suitable for use in the design of partially prestressed concrete members. Key words: concrete (prestress), design, partial prestressing, prestress losses.

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Lazzari, P. M., A. Campos Filho, F. P. S. L. Gastal, R. A. Barbieri, and R. C. Schwingel. "Automation of the evaluation of bonded and unbonded prestressed concrete beams, according to brazilian and french code specifications." Revista IBRACON de Estruturas e Materiais 6, no. 1 (February 2013): 13–54. http://dx.doi.org/10.1590/s1983-41952013000100003.

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This paper presents a suggestion for the automation of the design procedures of bonded and unbonded prestressed concrete flexural members, according to the Brazilian (NBR 6118:2007) and French (Règles BPEL 91) norm specifications. Prestressing of concrete structures has been increasingly used, mainly due to its building advantages, as well as allowing reducing crack incidence and element dimensions by the use of more resistant materials. Structure is analyzed by a numerical model that employs a hybrid type finite element for planar frames, considering geometric nonlinearity, cyclic loading and composite construction. The computational algorithm implemented considers full, partial and limited prestressing situations, evaluating in each case decompression limit state, limit state of cracking, ultimate limit state and final prestressing state. Finally, two examples comparing design situations according to the Brazilian and French norms are presented.

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9

Yolanda, Devy, and Priyanto Saelan. "Studi Analisis Batasan Persentase Prategang Parsial pada Struktur Balok Prategang (Hal. 48-59)." RekaRacana: Jurnal Teknil Sipil 4, no. 3 (September 25, 2018): 48. http://dx.doi.org/10.26760/rekaracana.v4i3.48.

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ABSTRAKPengurangan gaya prategang yang diperlukan pada suatu penampang beton prategang penuh (full prestressed) menyebabkan diperlukannya baja tulangan, dan beton prategang berperilaku menjadi beton prategang parsial. Pengurangan gaya prategang akan menimbulkan tegangan tarik yang bilamana tegangan tarik yang terjadi melampaui kuat tarik lentur beton maka akan terjadi retak. SNI 03-2847-2002 membolehkan penggunaan beton prategang parsial namun belum mensyaratkan batasan persentase prategang yang harus digunakan. Oleh karena itu dilakukan studi analisis untuk mengetahui persentase prategang minimal yang dapat digunakan. Studi kasus dilakukan pada persentase prategang 50, 60, 70, 80, dan 90. Dari hasil studi kasus didapatkan bahwa persentase prategang yang semakin kecil akan berakibat tegangan tarik dan lebar retak yang terjadi semakin besar. Persentase prategang harus dipilih sedemikian rupa sehingga lebar retak yang terjadi tidak melampaui lebar retak yang diizinkan. Pada kelima variabel penelitian, batasan minimal persentase prategang yang lebar retaknya tidak melebihi lebar retak yang diizinkan adalah 60%.Kata kunci: beton prategang parsial, persentase prategang, tegangan tarik, lebar retak ABSTRACTReducing the required prestressing force on a full prestressed concrete section requires the need for reinforcing steel, and prestressing concrete behaves to partial prestressed concrete. Reduction of the prestressing force will cause tensile stress when the tensile stress that goes beyond the tensile strength of the concrete will result in cracking. SNI 03-2847-2002 allows the use of partial prestressed concrete but does not require the limitation of the prestress percentage to be used. Therefore, an analytical study was conducted to determine the minimum prestressed percentage that can be used. The case study was carried out at 50, 60, 70, 80, and 90 prestressed percentages. From the case study it was found that the smaller the prestress percentage would result in greater tensile stress and crack width. The percentage of prestress shall be chosen so that the crack width does not exceed the allowable crack width. In the five research variables, the minimum limit of prestressing percentage whose crack width does not exceed the allowable crack width is 60%.Keywords: partial prestressed concrete, prestress percentage, tensile stress, crack width

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10

Freyermuth, Clifford L. "Practice of Partial Prestressing for Continuous Post-Tensioned Structures in North America." PCI Journal 30, no. 1 (January 1, 1985): 154–82. http://dx.doi.org/10.15554/pcij.01011985.154.182.

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11

Zhou, Y. X., F. B. Jin, M. Huang, J. W. Huang, Z. H. Liu, and L. C. Lu. "Effects of DC prestressing on partial discharge in oil-impregnated pressboard insulation." IEEE Transactions on Dielectrics and Electrical Insulation 23, no. 1 (February 2016): 460–68. http://dx.doi.org/10.1109/tdei.2015.005114.

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12

Selvachandran, P., S. Anandakumar, and K. L. Muthuramu. "Deflection of Steel Reinforced Concrete Beam Prestressed With CFRP Bar." Archives of Metallurgy and Materials 62, no. 3 (September 26, 2017): 1915–22. http://dx.doi.org/10.1515/amm-2017-0289.

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AbstractCarbon Fiber Reinforced polymer (CFRP) bars are weak in yielding property which results in sudden failure of structure at failure load. Inclusion of non-pretensioned steel reinforcement in the tension side of CFRP based prestressed concrete beam will balance the yielding requirements of member and it will show the definite crack failure pattern before failure. Experimental investigation has been carried out to study the deflection behavior of partially prestressed beam. Experimental works includes four beam specimens stressed by varying degree of prestressing. The Partial Prestressing Ratio (PPR) of specimen is considered for experimental works in the range of 0.6 to 0.8. A new deflection model is recommended in the present study considering the strain contribution of CFRP bar and steel reinforcement for the fully bonded member. New deflection model converges to experimental results with the error of less than 5% .

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13

De Stefani, Lorenzo, Roberto Scotta, Massimiliano Lazzari, and Anna Saetta. "Seismic improvement of slender masonry tower by using hysteretic devices and partial prestressing technique." Bulletin of Earthquake Engineering 12, no. 2 (October 17, 2013): 829–53. http://dx.doi.org/10.1007/s10518-013-9532-6.

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14

Shahawi, M. El, and B. deV Batchelor. "Design methods for partially prestressed concrete—a review." Canadian Journal of Civil Engineering 14, no. 2 (April 1, 1987): 269–77. http://dx.doi.org/10.1139/l87-039.

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Methods for use in the flexural analysis and design of a partially prestressed concrete section are outlined. A typical design example is presented and the results obtained by different design methods are compared. Methods proposed by Moustafa, Naaman and Siriaksorn, Bachmann, and Nilson are all suitable for design purposes. The graphs developed by Moustafa are useful in expediting design. The method proposed by Abeles, which is based on the use of a fictitious tensile stress in the concrete, is generally not recommended. Key words: concrete (prestress), design, flexure, partial prestressing.

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15

Zafar, Muhammad Naveed, Muhammad Azhar Saleem, Jun Xia, and Muhammad Mazhar Saleem. "Experimental Characterization of Prefabricated Bridge Deck Panels Prepared with Prestressed and Sustainable Ultra-High Performance Concrete." Applied Sciences 10, no. 15 (July 26, 2020): 5132. http://dx.doi.org/10.3390/app10155132.

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Enhanced quality and reduced on-site construction time are the basic features of prefabricated bridge elements and systems. Prefabricated lightweight bridge decks have already started finding their place in accelerated bridge construction (ABC). Therefore, the development of deck panels using high strength and high performance concrete has become an active area of research. Further optimization in such deck systems is possible using prestressing or replacement of raw materials with sustainable and recyclable materials. This research involves experimental evaluation of six full-depth precast prestressed high strength fiber-reinforced concrete (HSFRC) and six partial-depth sustainable ultra-high performance concrete (sUHPC) composite bridge deck panels. The composite panels comprise UHPC prepared with ground granulated blast furnace slag (GGBS) with the replacement of 30% cement content overlaid by recycled aggregate concrete made with replacement of 30% of coarse aggregates with recycled aggregates. The experimental variables for six HSFRC panels were depth, level of prestressing, and shear reinforcement. The six sUHPC panels were prepared with different shear and flexural reinforcements and sUHPC-normal/recycled aggregate concrete interface. Experimental results exhibit the promise of both systems to serve as an alternative to conventional bridge deck systems.

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16

Yang, Keun-Hyeok, Ju-Hyun Moon, and Hang-Yong Byun. "Effect of Partial Prestressing Ratio and Effective Prestress on the Flexural Behavior of Prestressed Lightweight Concrete Beams." Journal of the Korea Concrete Institute 23, no. 1 (February 28, 2011): 39–48. http://dx.doi.org/10.4334/jkci.2011.23.1.039.

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17

Batchelor, B. deV, and M. El Shahawi. "A review of cracking of partially prestressed concrete members." Canadian Journal of Civil Engineering 12, no. 3 (September 1, 1985): 645–52. http://dx.doi.org/10.1139/l85-071.

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A selective review of cracking of partially prestressed concrete members is presented. The main studies, together with the resulting methods for calculating maximum crack width, are critically examined. From an analysis of published test results it is shown that, in the light of the sparse data available, there is no point in using a complicated crack width formula for partially prestressed members. A simple expression for calculating crack width is proposed, which involves only the calculation of stress in the non-prestressed reinforcement. A strong case is made for further research in this area so that effects of the controlling parameters may be considered, where necessary. Key words: concrete (prestressed), cracking, crack width, partial prestressing.

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18

Kien, Nguyen Dinh. "Vibration frequency of prestress slender beams resting on Winkler elastic foundation." Vietnam Journal of Mechanics 28, no. 4 (December 31, 2006): 241–51. http://dx.doi.org/10.15625/0866-7136/28/4/5583.

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The present paper investigates the vibration frequency of slender beams prestressing by axial force and resting on an elastic Winkler foundation by the finite element method. A beam element taking the effects of both the prestress and foundation support into account is formulated using the expression of strain energy. Using the developed element, the natural frequencies of beams having various boundary conditions are computed for different values of the axial force and foundation stiffness. The influence of the axial force and the foundation stiffness on the frequency of the beams is investigated. The effect of partial support by the foundation and the type of mass matrices on the vibration frequency of the beam is also studied and highlighted.

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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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Cohn, M. Z., and Z. Lounis. "Moment redistribution in structural concrete codes." Canadian Journal of Civil Engineering 18, no. 1 (February 1, 1991): 97–108. http://dx.doi.org/10.1139/l91-012.

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Features of current moment redistribution provisions in American and European structural concrete standards are reviewed and compared. Some major differences are identified, along with their common objective of ensuring the rotation compatibility at the ultimate limit state of continuous structures. High amounts of moment redistribution (and the related economic advantages) sometimes tend to go against satisfactory service behaviour, particularly for prestressed members. Examination of moment redistribution formulae and main serviceability criteria suggests that some major variables currently neglected play a considerable role in ensuring the largest moment redistribution together with satisfactory service behaviour. Among these variables the dead to live load ratio, the degree of prestressing, the specified partial load factors, and the allowable performance target values (cracks, deflections, stresses) are investigated. Appropriate formulae to allow for their contribution are proposed, which may be easily implemented in any code. Finally, two numerical examples illustrate the practical implications of the theoretical aspects investigated in the paper. Key words: moment redistribution, reinforced and prestressed concrete, serviceability control, structural codes.

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Sun, Xiang-Tao, Dan Li, Wen-Yu He, Zuo-Cai Wang, and Wei-Xin Ren. "Grouting Quality Evaluation in Post-Tensioning Tendon Ducts Using Wavelet Packet Transform and Bayes Classifier." Sensors 19, no. 24 (December 5, 2019): 5372. http://dx.doi.org/10.3390/s19245372.

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The grouting quality of tendon ducts is very important for post-tensioning technology in order to protect the prestressing reinforcement from environmental corrosion and to make a smooth stress distribution. Unfortunately, various grouting defects occur in practice, and there is no efficient method to evaluate grouting compactness yet. In this study, a method based on wavelet packet transform (WPT) and Bayes classifier was proposed to evaluate grouting conditions using stress waves generated and received by piezoelectric transducers. Six typical grouting conditions with both partial grouting and cavity defects of different dimensions were experimentally investigated. The WPT was applied to explore the energy of received stress waves at multi-scales. After that, the Bayes classifier was employed to identify the grouting conditions, by taking the traditionally used total energy and the proposed energy vector of WPT components as input, respectively. The experimental results demonstrated that the Bayes classifier input with the energy vector could identify different grouting conditions more accurately. The proposed method has the potential to be applied at key spots of post-tensioning tendon ducts in practice.

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Taha, M. M. Reda, X. Xiao, J. Yi, and N. G. Shrive. "Evaluation of flexural fracture toughness for quasi-brittle structural materials using a simple test method." Canadian Journal of Civil Engineering 29, no. 4 (August 1, 2002): 567–75. http://dx.doi.org/10.1139/l02-044.

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As new structural concepts such as partial prestressing and steel-free bridge decks are more widely accepted and used, there is an increasing need for a reliable and reproducible fracture performance criterion that can describe resistance to crack growth. The required criterion should also be easy to determine experimentally so that it can be incorporated in structural specifications. The nonlinear behaviour of concrete and masonry materials suggested that quasi-brittle fracture mechanics approaches may be the most suitable for determining their fracture performance. The effective elastic crack model originally developed by Karihaloo and Nallathambi (1989) was modified to evaluate the critical crack depth under pure flexural stresses. A computer program was developed to calculate this depth iteratively from the experimental results. An experimental programme examining the fracture performance of four different structural materials (high performance concrete, mortar, fibre reinforced concrete, and masonry units) was carried out to examine the applicability of the model. As no post-peak data are required for the analysis, the model allows the use of a simple test setup to evaluate the fracture performance of quasi-brittle materials experimentally.Key words: fracture toughness, linear elastic fracture mechanics (LEFM), elastoplastic fracture mechanics (EPFM), quasi-brittle fracture mechanics, effective elastic crack, high performance concrete, masonry, fibre reinforced concrete.

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23

Kai, Yan, Zhang Yao, Cai Hao, Fan Lili, and Xin Zhang. "Postfire Safety Investigation on Prestressed RPC Beams after Exposure to Elevated Temperatures." Advances in Materials Science and Engineering 2020 (May 8, 2020): 1–14. http://dx.doi.org/10.1155/2020/7837418.

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Since the postfire safety of prestressed RPC beams after exposure to elevated temperatures needs to be studied and proved, this paper prepares eight smart prestressed RPC beams with intelligent sensors built in to monitor the internal temperature, force, and strain. The residual bearing tests after fire are carried out. The failure process of the beams under static load with different fire durations cover thickness of tendons, load ratio, bonded and unbonded tendons, and partial prestressing ratio, which are investigated. The load-deflection curves, crack distributions and developments, and strain variations are obtained, in addition to the damage mechanism and failure mode of the beams. The results show that the load-deflection curve of the prestressed RPC beam after fire has obviously three polylines, and the deflection points are where the cracks expand and the tendons yield. The failure procedure is the same as that of under-reinforced beams, while the height of the crushing zone is much lower than that of the balanced-reinforced beam at room temperature. The whole span deformation demonstrates a strong catenary effect, and the midspan deflection is approximately 1/40 of the effective span. The postfire safety of the bonded prestressed RPC beams is superior to that of unbonded prestressed RPC beams. The test results of this paper provide a basis for the safety performance evaluation and control of prestressed RPC beams after fire.

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"Partial Prestressing in Concrete Corbels and Deep Beams." ACI Structural Journal 89, no. 3 (1992). http://dx.doi.org/10.14359/9638.

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Chang, Zhaoqun, Guohua Xing, Jiahua Zhao, and Jiao Huang. "Feasibility and flexural behavior of RC beams prestressed with straight unbonded aluminum alloy tendons." Advances in Structural Engineering, December 18, 2020, 136943322098166. http://dx.doi.org/10.1177/1369433220981662.

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This paper investigates the feasibility and flexural behavior of reinforced concrete beams internally prestressed with straight unbonded aluminum alloy tendons by testing five partially prestressed beams and one reference beam. For each beam specimen, load-deflection curves, failure modes and cracking behavior, the relationship between load and strains in steel and prestressing aluminum alloy tendons were examined and analyzed. In particular, the effects of effective prestress, combined reinforcement index (CRI), and partial prestressing ratio (PPR) on flexure of concrete beams were discussed. The test results indicated that the spacing and width of concrete cracks of prestressed beams containing the same amount of bonded longitudinal steel reinforcement decreased with the increase of effective prestress, and the combined reinforcement index governs flexural behavior of the prestressed beams. The flexural crack width and displacement ductility exhibited a reduction with the increase of CRI. In addition, an analytical model was established to calculate the flexural strength and corresponding deflection at midspan of the concrete beams internally prestressed with unbonded aluminum alloy tendons by suggesting a new simplified curvature distribution, which is more accordant with the original curvature distribution. The proposed model provides a relatively good estimation of the flexural capacity and midspan deflection of the prestressed beams.

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Oukaili, Nazar, and Mohammed Khattab. "FLEXURAL DUCTILITY OF STRUCTURAL CONCRETE MEMBERS SUBJECTED TO LIMITED CYCLES OF REPEATED LOADING." Proceedings of International Structural Engineering and Construction 6, no. 1 (May 2019). http://dx.doi.org/10.14455/isec.res.2019.81.

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For structural concrete members that may expose to serious earthquake, overload or accident impact, the design of ductility must be given the same importance as the flexural strength. The aim of this investigation is to study the change in ductility of structural concrete flexural members during their exposure to limited cycles of repeated loading. Twenty full-scale beam specimens have been fabricated in to two identical groups; each group consisted of ten specimens. The first group was tested under monotonic static loading to failure and regarded as control beams, while the specimens of the second group were subjected to ten cycles of repeated loading with constant load interval, which ranged between 40% and 60% of ultimate load. Specimens in each group were categorized as follows: two traditional reinforced concrete specimens with different intensity of tension reinforcement; three partially prestressed specimens with bonded strands; three partially prestressed specimens with unbonded strands; and two fully prestressed concrete specimens. The main variable, which was considered for all specimens was the partial prestressing ratio (PPR). It was observed that, the ductility of reinforced concrete beams was insignificantly increased during subjecting to limited repeated loading. For fully prestressed and partially prestressed concrete beams with high level of PPR, the ductility was significantly enhanced, while, it was decreased for specimens with small level of PPR.

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Journal articles on the topic 'Partial Prestressing'

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