Academic literature on the topic 'Bonded post-tensioning'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Bonded post-tensioning.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Bonded post-tensioning"
1
Sayed-Ahmed, Ezzeldin Y., and Nigel G. Shrive. "A new steel anchorage system for post-tensioning applications using carbon fibre reinforced plastic tendons." Canadian Journal of Civil Engineering 25, no. 1 (January 1, 1998): 113–27. http://dx.doi.org/10.1139/l97-054.
Full textAbstract:
During the past half century, the use of prestressing in different structures has increased tremendously. One of the most important techniques of prestressing is post-tensioning. The main problem associated with post-tensioning in different structures is the corrosion of the prestressing steel tendons even with well-protected steel. New materials, fibre reinforced plastics or polymers (FRP), which are more durable than steel, can be used for these tendons/strands and thus overcome the corrosion problem. However, different shortcomings appear when FRP tendons are introduced to post-tensioning prestressing applications. For carbon fibre plastic tendons (CFRP), there is no suitable anchorage system for post-tensioning applications. Some of the anchorages developed by others for use with FRPs are therefore described and assessed. A new anchorage system developed by the authors, which can be used with bonded or unbonded CFRP tendons in post-tensioning applications, is described. The results of direct tension and fatigue tests on CFRPs anchored with the new system are presented.Key words: anchorage system, cyclic loading, fatigue, fibre reinforced plastics, finite element analysis, post-tension, prestressed concrete, prestressed masonry, strands, tendons.
2
Aziz, Mohamad Abdel, George Abdel-Sayed, Faouzi Ghrib, Nabil F. Grace, and Murty K. S. Madugula. "Analysis of concrete beams prestressed and post-tensioned with externally unbonded carbon fiber reinforced polymer tendons." Canadian Journal of Civil Engineering 32, no. 6 (December 1, 2005): 1138–51. http://dx.doi.org/10.1139/l05-071.
Full textAbstract:
Fiber reinforced polymer (FRP) tendons are being increasingly used nowadays in prestressing and (or) post-tensioning concrete structures. However, designers are faced with lack of practical analysis procedure that leads to proper evaluation of their structural performance, especially when bonded prestressing is combined with unbonded post-tensioning. This paper presents an analytical procedure for these beams. It examines the load–defelction characteristics and proceeds to estimate the ultimate load carrying capacity by taking into consideration the change of stress that occurs in the externally unbonded tendons during different stages of loading. The analytical procedure uses the concept of effective moment of inertia of concrete beams. The equations used are developed by ACI Committee 440, the Intelligent Sensing for Innovative Structures (ISIS) Canada Research Network, and the Comité Euro-International du Béton - Fédération International de la Précontrainte (CEB-FIP), for calculating the deflection of beams reinforced with carbon fiber reinforced polymer (CFRP) tendons. Finite element analyses have been conducted to verify the proposed analytical method. Two experimental programs were used to validate the proposed analytical method. The experimental findings of two box beams reinforced with bonded and unbonded external tendons are compared with finite element analyses and the analytical results. A full-scale test for an internally and externally prestressed double-T beam was undertaken at Construction Technology Laboratories Inc., Skokie, Illinois. The results from this experimental work were used to validate the analytical procedure.Key words: bonded CFRP tendons, concrete, post-tensioning, unbonded CFRP tendons.
3
Mohammed, Abbas, Khattab Saleem Abdul-Razzaq, Nildem Tayşi, and Awat FAQE. "Modelling of Bonded Post-Tensioned Concrete Cantilever Beams under Flexural Loading." Civil Engineering Journal 3, no. 7 (July 30, 2017): 463–79. http://dx.doi.org/10.28991/cej-2017-00000105.
Full textAbstract:
Prestressing is widely used technic all over the world for constructions of buildings, bridges, towers, offshore structures etc. due to its efficiency and economy for achieving requirements of long span with small depth. It is used for flexural strengthening of reinforced concrete structures for improving cracking loads and decreasing deflections due to service loads. There are two methods for prestressing (pre-tensioning and post-tensioning). In this paper, a three-dimensional nonlinear Finite Element (FE) method is used to determine the behaviour of Post-Tensioned (PT) concrete cantilever beams with different tendon profiles. Numerical analyses ANSYS package program is used for analysis of beams. The results from FE analysis is verified by experimental reference test result and good agreement is achieved. This paper is focused on the effect of different tendon profiles on the flexural behaviour of Bonded Post Tensioned (BPT) reinforced concrete cantilever beams. Six models with different tendon profiles are investigated. These models are without tendons, two tendons at the bottom, middle, top, parabolic tendons with one draped point and two draped points. Failure loads, deflections, and load versus deflection relationships for all models are examined and it is seen that the beam with one draped tendon profile shows a highest performance.
4
Cupać, Jagoda, Christian Louter, and Alain Nussbaumer. "Post-tensioning of glass beams: Analytical determination of the allowable pre-load." Glass Structures & Engineering 6, no. 2 (March 30, 2021): 233–48. http://dx.doi.org/10.1007/s40940-021-00150-0.
Full textAbstract:
AbstractThe effectiveness of post-tensioning in enhancing the fracture resistance of glass beams depends on the level of compressive pre-stress introduced at the glass edge surface that will in service be exposed to tensile stresses induced by bending. Maximum pre-load that can be applied in a post-tensioned glass beam system, yielding maximum compressive pre-stress, is limited by various failure mechanisms which might occur during post-tensioning. In this paper, failure mechanisms are identified for a post-tensioned glass beam system with a flat stainless steel tendon adhesively bonded at the bottom glass edge, including the rupture of the tendon, glass failure in tension and adhesive/glass failure in the load introduction zone. Special attention is given to the load introduction failure given that the transparent nature of glass limits the use of vertical confinement usually applied in concrete. An analytical model for determination of the allowable pre-load in post-tensioned glass beams is proposed, based on the model applied for externally post-tensioned concrete beams. The model is verified with the results of a numerical model, showing good correlation, and applied in a parametric study to determine the influence of various beam parameters on the effectiveness of post-tensioning glass beams.
5
Mohammed, Khaleel, M. Jameel, Zainah Ibrahim, and Chee Tan. "Performance of a Ductile Hybrid Post-Tensioned Beam-to-Column Connection for Precast Concrete Frames under Seismic Loads: A Review." Applied Sciences 11, no. 16 (August 16, 2021): 7497. http://dx.doi.org/10.3390/app11167497.
Full textAbstract:
The performance of precast concrete frame structures against seismic loads mainly depends on the beam-to-column connection. A ductile hybrid connection consists of unbonded post-tensioning steel and bonded reinforcement bars, both of which provide overall moment resistance to the frame. Post-tensioning steel acts as a restoring force which brings the structure back to its initial position upon unloading. Mild steel acts as an energy dissipator which yields in tension and compression. To evaluate the performance of precast frame structures, the structural engineer requires extensive knowledge of the complex nonlinear behavior of the connection. Standardization to mass produce is one of the benefits of precast construction, but with standardization in design there is severe risk. All previous earthquakes have clearly shown that continuous repetition of accepted practice without proper engineering review can lead to disaster. It is important to understand how different parameters of the connection influence the behavior and performance of the frame against seismic loads. The present study helps structural engineers and researchers with a detailed review of hybrid post-tensioned connections. This review is focused mainly on precast beam-to-column connections, studies on the development of hybrid connections, performance evaluations of hybrid connections, and the performance evaluation of precast frames with hybrid connections.
6
Rocha, Jorge, Eduardo Pereira, and José Sena-Cruz. "Feasibility of mechanical post-tensioning of annealed glass beams by activating externally bonded Fe-SMA reinforcement." Construction and Building Materials 365 (February 2023): 129953. http://dx.doi.org/10.1016/j.conbuildmat.2022.129953.
Full text
7
Al-Baghdadi, Nadher H., and Balqees A. Ahmed. "Field tests of grouted ground anchors in the sandy soil of Najaf, Iraq." Open Engineering 12, no. 1 (January 1, 2022): 905–17. http://dx.doi.org/10.1515/eng-2022-0359.
Full textAbstract:
Abstract This article presents test results documentation for four grouted ground anchors embedded in sandy soil. Three anchors were trial, while one was a working anchor. One trial anchor is instrumented with eight resistance-type strain gauges glued on the corrugated pipe and embedded within the grouted body. An acceptance test was made for all anchors to determine the working load. Acceptance criteria suggested by the Post-Tensioning Institute were applied, and the working anchor did not pass the creep criterion, so it was taken out of service. The strain measurements indicated that the compression stresses were generated along the free length, while the tension stresses were generated along the bonded length. The transition point, which is the point with zero axial stress within the grouted body, was located at a distance of 10–12% of the bonded length, measured from the proximal end of the bonded length. The skin friction distribution along the grouted body was nonuniform, and it had a peak at the transition point. The maximum measured value of the skin friction is almost compatible with the estimated one by Fujita’s formula. The skin friction developed along the free length indicates a significant contribution of the free length to the pullout capacity.
8
Sayed-Ahmed, Ezzeldin Y., Amr H. Riad, and Nigel G. Shrive. "Flexural strengthening of precast reinforced concrete bridge girders using bonded carbon fibre reinforced polymer strips or external post-tensioning." Canadian Journal of Civil Engineering 31, no. 3 (June 1, 2004): 499–512. http://dx.doi.org/10.1139/l04-005.
Full textAbstract:
Strengthening of reinforced concrete bridge girders has become a major concern. Many reinforced concrete highway bridges were constructed in Canada using precast reinforced concrete girders, and currently many of them need rehabilitation. Thus, two techniques for flexural strengthening of precast reinforced concrete bridge girders (HC-type) were investigated experimentally. The first technique involved bonding carbon fibre reinforced polymer (CFRP) strips to the soffits of the girders. The second technique was classical external post-tensioning with steel bars. A simple, yet innovative method was developed for applying the external prestressing to these girders. The experimental investigation was performed on full-scale girders from a dismantled bridge in Alberta (Canada). Outcomes of the experimental investigation led to the conclusion that classical methods of flexural strengthening (e.g., external prestressing) should not be completely disregarded. Also, an additional mode of failure needs to be added to currently available prediction models for estimating the gain in flexural strength of reinforced concrete girders retrofitted using bonded CFRP strips.Key words: bridges, CFRP, flexure strengthening, precast girders, post tension, prestressing, rehabilitation.
9
Azad, Fathima. "Analysis of Columns Strengthened using Fibre Reinforced Cementitious Matrix Jackets." International Journal for Research in Applied Science and Engineering Technology 9, no. 9 (September 30, 2021): 1795–800. http://dx.doi.org/10.22214/ijraset.2021.38272.
Full textAbstract:
Abstract: Maintenance, repair and strengthening of existing concrete structures, either reinforced or prestressed,are important activities of civil engineers. Nowadays different techniques are available for the strengthening. Various techniques were adopted for strengthening RC structures, namely, steel plates, external post tensioning, externally bonded Fibre-Reinforced Polymer (FRP), and near- surface-mounted FRP systems to increase shear and flexural capacity. During the last few decades, strengthening of concrete structural elements by fibre-reinforced polymer has become a widely used technique. But it has several disadvantages due to the epoxy resin like debonding of FRP from the concrete structure, unstable nature of the epoxy at higher temperatures etc. To overcome this, an upgraded system was introduced as an alternative for FRP known as Fibre Reinforced Cementitious Matrices (FRCM). The objective of this paper is to investigate the feasibility of Fibre-Reinforced Cementitious-Matrix materials as an alternative external strengthening technique for RC members. Columns with circular geometry were wrapped with different fibre materials using cementitious matrix. The analysis was done using ANSYS software. Keywords: RC columns, FRCM, Strengthening, fibre, ANSYS
10
Zhang, Burong, and Brahim Benmokrane. "Large model test of prestressed carbon fibre reinforced polymer ground anchors." Canadian Journal of Civil Engineering 32, no. 6 (December 1, 2005): 1064–74. http://dx.doi.org/10.1139/l05-058.
Full textAbstract:
This paper presents a full-scale prestressed ground anchor model test with carbon fibre reinforced polymer (CFRP) 9-bar tendons. The main objectives of this laboratory study were to evaluate the serviceability of the developed bond-type anchorage for post-tensioning applications with CFRP multibar tendons and to study load transfer mechanism of CFRP multibar tendons to surrounding rock mass. A cement-based mortar-filled steel tube was used to simulate a rock mass environment. Extensive instrumentation including resistance strain gauges, fibre optic sensors, embedded strain gauges, and linear variable displacement transducers (LVDTs) were used to monitor the behaviour of the anchor. The test results show that the tested CFRP 9-bar anchor presents an acceptable tensile behaviour under a load of 0.6fpu in accordance with existing codes. The CFRP multibar anchor presents a similar strain distribution profile as that for conventional steel anchors, except giving a shorter load transfer length. It is expected that CFRP 9-bar anchors require a minimum anchor bonded length of 2000 mm with plain cement grouts.Key words: anchor, anchorage, FRP, tendon, slip.
Dissertations / Theses on the topic "Bonded post-tensioning"
1
Sabri, Amirreza. "Seismic Retrofit of Load Bearing URM Walls with Internally Placed Reinforcement and Surface-Bonded FRP Sheets." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40675.
Full textAbstract:
Concrete block masonry is a common building material used worldwide, including Canada. Reinforced masonry buildings, designed according to the requirements of recent building codes, may result in seismically safe structures. However, unreinforced masonry (URM) buildings designed and constructed prior to the development of modern seismic design codes are extremely vulnerable to seismic induced damage. Replacement of older seismically deficient buildings with new and seismically designed structures is economically not feasible in most cases. Therefore, seismic retrofitting of deficient buildings remains to be a viable seismic risk mitigation strategy. Masonry load bearing walls are the most important elements of such buildings, potentially serving as lateral force resisting systems.
A seismic retrofit research program is currently underway at the University of Ottawa, consisting of experimental and analytical components for developing new seismic retrofit systems for unreinforced masonry walls. The research project presented in this thesis forms part of the same overall research program. The experimental component includes design, construction, retrofit and testing of large-scale load bearing masonry walls. Two approaches were developed as retrofit methodologies, both involving reinforcing the walls for strength and deformability. The first approach involves the use of ordinary deformed steel reinforcement as internally added reinforcement to attain reinforced masonry behaviour. The second approach involves the use of internally placed post-tensioning tendons to attain prestressed masonry behaviour. The analytical component of research consists of constructing a Finite Element computer model for nonlinear analysis of walls and conducting a parametric study to assess the significance of retrofit design parameters. The results have led to the development of a conceptual retrofit design framework for the new techniques developed, while utilizing the seismic provisions of the National Building Code of Canada and the relevant CSA material standards.
2
Kam, Weng Yuen. "Selective Weakening and Post-Tensioning for the Seismic Retrofit of Non-Ductile RC Frames." Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2010. http://hdl.handle.net/10092/5237.
Full textAbstract:
This research introduces and develops a counter-intuitive seismic retrofit strategy, referred to as “Selective Weakening” (SW), for pre-1970s reinforced concrete (RC) frames with a particular emphasis on the upgrading of exterior beam-column joints. By focusing on increasing the displacement and ductility capacities of the beam-column joints, simple retrofit interventions such as selective weakening of the beam and external post-tensioning of the joint can change the local inelastic mechanism and result in improved global lateral and energy dissipation capacities.
The thesis first presents an extensive review of the seismic vulnerability and assessment of pre-1970s RC frames. Following a review of the concepts of performance-based seismic retrofit and existing seismic retrofit solutions, a thorough conceptual development of the SW retrofit strategy and techniques is presented. A “local-to-global” design procedure for the design of SW retrofit is proposed. Based on the evaluation of the hierarchy of strength at a subassembly level, a capacity-design retrofit outcome can be achieved using various combinations of levels of beam-weakening and joint post-tensioning. Analytical tools for the assessment and design of the SW-retrofitted beam-column joints are developed and compared with the test results.
Nine 2/3-scaled exterior joint subassemblies were tested under quasi-static cyclic loading to demonstrate the feasibility and effectiveness of SW retrofit for non-ductile unreinforced beam-column connections. Parameters considered in the tests included the presence of column lap-splice, slab and transverse beams, levels of post-tensioning forces and location of beam weakening. Extensive instrumentation and a rigorous testing regime allowed for a detailed experimental insight into the seismic behaviour of these as-built and retrofitted joints. Experimental-analytical comparisons highlighted some limitations of existing seismic assessment procedures and helped in developing and validating the SW retrofit design expressions. Interesting insights into the bond behaviour of the plain-round bars, joint shear cracking and post-tensioned joints were made based on the experimental results.
To complement the experimental investigation, refined fracture-mechanic finite-element (FE) modelling of the beam-column joint subassemblies and non-linear dynamic time-history analyses of RC frames were carried out. Both the experimental and numerical results have shown the potential of SW retrofit to be a simple and structurally efficient structural rehabilitation strategy for non-ductile RC frames.
3
Muhaj, Helisa. "Seismic strengthening of reinforced concrete beams by post-tensioning with anchorages by bonding." Doctoral thesis, 2020. http://hdl.handle.net/10362/103102.
Full textAbstract:
RC moment resisting frame buildings are one of the most used structural systems in seismic
prone regions. These structures dissipate energy by concentrating the inelastic behaviour (i.e. the damage)
in the plastic hinge regions of the structural elements, that form preferably on the beams ends.
Since Capacity Design has been part of the Design Codes for some years now, some moment resisting
frame buildings have suffered seismic events. Although in most of the cases the ductile performance
of structures has successfully preserved the human lives and no collapse has occurred, deficiencies
regarding the residual capacity and high level of post-earthquake damages have surfaced. The importance
of other solutions that offer higher cost-efficiency and are more resilient has emerged.
Some studies have shown that damage limitation leads to high seismic performance of structural
systems even. This technology was developed at first for application in precast industry, PRESSS
program. Considering the vast amount of existing structures built following the Capacity Design and
the advantages of Damage Avoidance Design, strengthening by post-tensioning with adhesive anchorages
is proposed in this dissertation as a promising intervention for improving the seismic behaviour
of ductile beams. This solution takes advantage of self-centering capacity of unbonded PT strands,
whereas development of bonded anchorages turns this solution suitable for application in residential
/ business frame buildings. The results obtained from four RC beams tested experimentally will be
presented herein, including one reference and three strengthened specimens. The strengthened beams
had reduced residual deformation and enhanced load capacity. The behaviour of the beams tested
experimentally was also studied through numerical analysis. The attained results show that strengthening
by post-tensioning with bonded anchorages represents a suitable intervention for reducing the
impact of seismic events. Reduced damage of structural elements in RC frame after a seismic event
leads to reduced (or absence) cost of repair and building downtime.
Books on the topic "Bonded post-tensioning"
1
Corrugated plastic ducts for internal bonded post-tensioning: Technical report. Lausanne, Switzerland: International Federation for Structural Concrete, 2000.
Find full textConference papers on the topic "Bonded post-tensioning"
1
Grüske-Weißenbach, Nils, and Chris Fielding. "Design validation via Infrastructure Health Monitoring of the Circular bridge project." In IABSE Conference, Seoul 2020: Risk Intelligence of Infrastructures. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2020. http://dx.doi.org/10.2749/seoul.2020.358.
Full textAbstract:
<p>As part of the Dutch Government's plan to implement schemes to make bridges re-usable, we are presenting a completed Rijkswaterstaat (Road Authority of the Netherlands) pilot project. The ambitious plan to become "circular" (i.e. re-usable) by 2030 requires to rethink the traditional construction process from the ground up. That means that the conventional way in which bridges are commissioned and build, is no longer applicable. The lifecycle process from design stage to execution and demolition needs to change.</p><p>The Circular bridge pilot project demonstrates how bridge engineers designed the structure that utilizing standardized pre-cast concrete segments for a 200-year lifespan. These elements are assembled akin to Lego pieces and post-tensioned (PT) in the longitudinal and transversal directions. When the initial in-place service life of the bridge is reached (say 40 years), these blocks can be de-installed and re-assembled at a different location, hence the term circular.</p><p>In order to confirm the design principles and overcome the requirement that the post-tensioning always needs to be bonded within the structure it was necessary to monitor the performance of the bridge during the execution phase. This, in EC terms, is referred to as "design-by-testing". To validate the design, a multi-component Infrastructure Health Monitoring (IHM) system was deployed. The IHM system consisted of camera control of traffic flows (CCTV) measuring vehicle counts, speeds and directions and featured the following sensing instrumentation: temperatures, bridge deflections, bird-gapping between the blocks and force monitoring. As part of the IHM system, alerts and alarms were programmed to be sent to engineers in case measurements exceeded pre-defined thresholds.</p>
2
Sherif, Muhammad, Osman Ozbulut, Asheesh Landa, and Reginald F. Hamilton. "Self-Post-Tensioning for Concrete Beams Using Shape Memory Alloys." In ASME 2014 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/smasis2014-7564.
Full textAbstract:
This study explores the use of shape memory alloys for self-post-tensioning concrete beams. SMAs have the ability to regain their original shape after being deformed up to 6–8% strain. This shape recovery is a result of an underlying reversible solid-solid phase transformation, which can be induced by either a stress (superelastic effect) or a temperature change (shape memory effect). The shape memory effect can be exploited to prestress concrete. The heat of hydration of grout can thermally activate SMA tendons to obtain self-post-tensioned (SPT) concrete. NiTi-based SMAs are promising due to their corrosion resistance and resistance against low frequency/cycle fatigue failure. NiTiNb alloys are a class of SMAs that exhibit a wide temperature hysteresis and transformation temperatures near the service temperatures required for practical application. Here, NiTiNb shape memory alloys are studied to design an optimized SMA that can be activated using hydration heat. The material design and characterization of the SMA tendons are discussed. The temperature increase due to the heat of hydration of four commercially available grouts is investigated. The bond behavior of SMA tendons is evaluated through pullout tests. Digital Image Correlation method is used for monitoring the slippage of the SMA tendons. The feasibility of developing SPT concrete is assessed through experimental studies. The use of SMAs, which possess high fatigue and corrosion resistance, as post-tensioning tendons in concrete members will increase the service life and provide life cycle cost savings for concrete bridges. The replacement of steel tendons with SMA prestressing tendons will prevent corrosion-induced deterioration of tendons in concrete structures. The use of heat of hydration of grout to activate the shape memory effect of SMA tendons will provide self-stressing capability. This will greatly simplify the tendon installation. The need for jacking equipment or electrical source will be eliminated.