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Book Flexural Behavior of Concrete Beams Prestressed with Bonded and Unbonded Tendons

Download or read book Flexural Behavior of Concrete Beams Prestressed with Bonded and Unbonded Tendons written by Adi Abu-Obeidah and published by . This book was released on 2017 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of unbonded tendons in prestressed concrete beams has been widely utilized in bridges, parking structures, and residential buildings for strengthening, rehabilitation or repair of such members. With the growth of live load and the increase of damaged concrete members, there is a need to develop and utilize new techniques for more efficient and improved designs in prestressed concrete members. This research presents an experimental and analytical investigation for the use of combination of bonded and unbonded tendons in the same concrete members. With the availability of high strength concrete, as well as the development of new prestressing technologies, the process can be easily performed at the site for repair or capacity upgrading resulting in longer spans for the same section depth or shallower sections. There is a knowledge gap on the behavior of concrete beams prestressed with hybrid tendons and a need to fully understand their overall behavior under full service loads. The hybrid technique introduces unbonded CFRP tendons, which is resistant to corrosion. In addition, CFRP tendons exhibit linear stress-strain relationship resulting in more accurate predictions for the tendon stress at ultimate. This hybrid system presents a challenge in developing an analytical model that could predict their behavior since the unbonded tendon is not bonded with the concrete. This investigation included the testing of 15 High Strength Concrete (HSC) beams prestressed with hybrid tendons. Results from the experimental study included number of cracks, load-deflection behavior, and strains in prestressing strand, reinforcing steel, and concrete. This study emphasizes the prediction of the ultimate stress of the unbonded tendon (fps) in unbonded or hybrid system for computing the ultimate moment resistance. Finite element modeling and analysis of various beams is performed. Based on a comparison of equations available in the literature as well as code provisions with the experimental results, a simplified prediction equation for predicting the stress in the unbonded tendons at ultimate is recommended.

Book Full Range Behaviour of Concrete Beams Partially Prestressed with Unbonded Tendons

Download or read book Full Range Behaviour of Concrete Beams Partially Prestressed with Unbonded Tendons written by Karmen Tso and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Full-range Behaviour of Concrete Beams Partially Prestressed With Unbonded Tendons" by Karmen, Tso, 曹嘉雯, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: ABSTRACT OF THESIS ENTITLED Full-range Behaviour of Concrete Beams Partially Prestressed with Unbonded Tendons submitted by TSO Karmen for the degree of Master of Philosophy at The University of Hong Kong in February 2007 External prestressing can be applied to both new construction and retrofitting of existing reinforced and prestressed concrete structures. The behaviour of prestressed concrete structures with unbonded tendons differs significantly from that of those with bonded tendons after the working stage. To assess the safety of such structures, it is necessary to carry out full-range analysis, with particular attention to the post-peak behaviour. This thesis presents the results of an experimental study of externally prestressed concrete beams with either conventional or non-conventional tendons, which were tested to failure. The specimens tested all had T-sections prestressed by two external tendons with one on each side. Two types of tendon were used, namely 7-wire steel strands of 10.5 mm diameter and aramid fibre reinforced polymer (AFRP) tendons of 13.5 mm diameter. Unlike the steel tendons, the fibre reinforced polymer (FRP) tendons are not prone to corrosion. However, the prestressing operations for FRP tendons had to be modified to suit. In the experiments, different factors were taken into consideration. They included the level of prestressing force, concrete strength, area of non-prestressed steel reinforcement and partial prestressing ratio. - 1 - The full-range behaviour of partially prestressed concrete with either external unbonded steel or fibre reinforced polymer (FRP) tendons was significantly affected by second-order effects, as demonstrated in the strain profiles of top and bottom non- prestressed reinforcement and the variations of curvature and neutral axis depth. During the investigation of tendon force, the friction loss at deviator was found to be much greater than the friction loss estimated from the coefficients of friction given by the manufacturers. The equivalent coefficients of friction of steel and AFRP tendon were studied. Lastly, by using various ductility and deformability indices, the ductility or deformability of partially prestressed concrete with external unbonded tendons were investigated. The most suitable ductility or deformability index is proposed. (TSO Karmen) (302 words) - 2 - DOI: 10.5353/th_b3822557 Subjects: Tendons (Prestressed concrete) - Testing Prestressed concrete beams - Testing

Book ON THE FLEXURAL BEHAVIOR OF CONCRETE BEAMS PRESTRESSED WITH UNBONDED INTERNAL AND EXTERNAL TENDONS UNBONDED TENDONS BEAMS

Download or read book ON THE FLEXURAL BEHAVIOR OF CONCRETE BEAMS PRESTRESSED WITH UNBONDED INTERNAL AND EXTERNAL TENDONS UNBONDED TENDONS BEAMS written by FADI MAAZ ALKHAIRI and published by . This book was released on 1991 with total page 916 pages. Available in PDF, EPUB and Kindle. Book excerpt: from 15 different investigations. Excellent correlation was obtained between predicted vs. experimental results. The present investigation suggests that shear deformations may have some effect on the stress increase in unbonded tendons for beams having low span-to-depth ratios, while eccentricity variations in external tendons significantly affect the overall behavior for beams having high span-to-depth ratios.

Book Flexural Behavior of High Strength Concrete Beams Prestressed with Unbonded Tendons

Download or read book Flexural Behavior of High Strength Concrete Beams Prestressed with Unbonded Tendons written by Padit Tanchan and published by . This book was released on 2001 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Flexural Behavior Strength and Ultimate Design of Prestressed Concrete Beams

Download or read book Flexural Behavior Strength and Ultimate Design of Prestressed Concrete Beams written by Narbey Khachaturian and published by . This book was released on 1963 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Flexural Behaviour of Unbonded Post tensioned Partially Prestressed Concrete Beams

Download or read book Flexural Behaviour of Unbonded Post tensioned Partially Prestressed Concrete Beams written by Ashraf Elzanaty and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Flexural Behavior of Prestressed Concrete Composite Tee beams

Download or read book Flexural Behavior of Prestressed Concrete Composite Tee beams written by James Bryson and published by . This book was released on 1970 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestressed Tee-beams constructed by the split-beam method were tested to failure in flexure to study the behavior and ultimate strength of these beams and to compare their flexural characteristics with those of prestressed beams of conventional construction. Results showed that composite split-beams behaved similarly to the monolithically constructed beams on the basis of flexural response and ultimate load.

Book Flexural Behavior of Unbonded Prestressed Concrete Beams

Download or read book Flexural Behavior of Unbonded Prestressed Concrete Beams written by David Wai Sum Ho and published by . This book was released on 1972 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Bond and Flexural Behaviour of Self Consolidating Concrete Beams Reinforced and Prestressed with FRP Bars

Download or read book Bond and Flexural Behaviour of Self Consolidating Concrete Beams Reinforced and Prestressed with FRP Bars written by Slamah Krem and published by . This book was released on 2013 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self consolidating concrete (SCC) is widely used in the construction industry. SCC is a high performance concrete with high workability and consistency allowing it to flow under its own weight without vibration and making the construction of heavily congested structural elements and narrow sections easier. Fiber reinforced polymer (FRP) reinforcement, with its excellent mechanical properties and non-corrosive characteristic, is being used as a replacement for conventional steel reinforcement. In spite of the wide spread of SCC applications, bond and flexural behaviour of SCC beams reinforced or prestressed with FRP bars has not been fully studied. Furthermore, the ACI 440.1R-06 equation for determining the development length of FRP bars is based on Glass FRP (GFRP) bars and may not be applicable for Carbon FRP (CFRP) bars. This research program included an experimental and analytical study to investigate the flexural and bond behaviour of SCC beams reinforced with FRP bars and SCC beams prestressed with CFRP bars.

Book Flexural Behaviour of Steel Fibre Prestressed Concrete Beams

Download or read book Flexural Behaviour of Steel Fibre Prestressed Concrete Beams written by Alberto Kenneth and published by . This book was released on 2012 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: