Download or read book Experimental and Analytical Evaluation of the Behavior of Concrete T Beams with External Prestressing written by Nada Emile Khairallah and published by . This book was released on 1997 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior and flexural resistance of reinforced concrete T beams strengthened using external prestressing were experimentally and analytically investigated. The behavior at both serviceability and limit states were evaluated. A total of twelve beams was tested. The main test variables included ratio of the ordinary reinforcing steel, magnitude of the external prestressing force (or area of external prestressing steel), and profile of the external prestressing tendons. The results indicated clearly that external prestressing is a very powerful technique for strengthening concrete flexural members. The use of external prestressing delayed the formation of flexural cracks, reduced the service load deflections, enhanced the shear performance, and increased the ultimate flexural strength up to 14percent in comparison with conventional reinforced concrete specimens. However, the corresponding improvement in the strength and behavior is accompanied by reduction in the ductility of flexural failure. Everything else being constant, external tendons with deviated profile were more effective in increasing the flexural strength than tendons with straight profile. The experimental results were reproduced analytically using a nonlinear analysis method. The nonlinear analysis method requires constitutive analytical relationships of the stress-strain curves of the constituent materials, namely, concrete, prestressing steel, and ordinary steel, and iteration procedure to satisfy deformation compatibility and force equilibrium at every stage during the load-deformation response of the member. The analytical results based on nonlinear analysis were in very good agreement with the experimental results. Furthermore, comparison was made between the experimental results of the stress in the external prestressing steel and available design equations. Based on this comparison, it was found that the stress in the external prestressing steel and the nominal flexural resistance of externally prestressed members can be predicted with reasonable accuracy using the ACI Building Code approach for beams prestressed with internal unbonded tendons.

Download or read book Experimental and Analytical Evaluation of the Behavior of Continuous Concrete Beams Prestressed with External Tendons written by Jack Adel al-Hajj and published by . This book was released on 2001 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: After a short introduction of the electron spin resonance theory, the theory of the g-factor, and a discussion of the asymmetry of the spectra, a survey of the literature on the phenoxazines is presented. Two specific ways of preparation of free radicals have been described in detail. The experiment shows that two free radicals are obtained from resazurin. The first one is proved to be the free radical of resazurin, while the second one is shown to belong to resorufin, which is obtained from resazurin by breaking the N-0 bond. The spectra of phenoxazine, resorufin, and resazurin are analyzed and the hyperfine structure constants are compared with the calculation of spin densities based on Hfickel Molecular Orbital theory. In the case of resorufin and resazurin, better agreement is obtained than in the case of phenoxazine* The g-values of the above molecules have been measured accurately. The asymmetry of the obtained spectra has been interpreted and is found to be in accordance with the relaxation theory presented in the literature.

Download or read book Experimental and Analytical Study of the Behavior of Concrete Beams Prestressed with Unbonded Tendons written by Muhamed H. Harajli and published by . This book was released on 1990 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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

Download or read book Research Report written by American University of Beirut and published by . This book was released on 1995 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of SECON 19 written by Kaustubh Dasgupta and published by Springer Nature. This book was released on 2019-12-17 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers peer-reviewed contributions presented at the 3rd National Conference on Structural Engineering and Construction Management (SECON’19), held in Angamaly, Kerala, India, on 15-16 May 2019. The meeting served as a fertile platform for discussion, sharing sound knowledge and introducing novel ideas on issues related to sustainable construction and design for the future. The respective contributions address various aspects of numerical modeling and simulation in structural engineering, structural dynamics and earthquake engineering, advanced analysis and design of foundations, BIM, building energy management, and technical project management. Accordingly, the book offers a valuable, up-to-date tool and essential overview of the subject for scientists and practitioners alike, and will inspire further investigations and research.

Download or read book Externally Bonded FRP Reinforcement for RC Structures written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2001-01-01 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: In December 1996, the then CEB established a Task Group with the main objective to elaborate design guidelines for the use of FRP reinforcement in accordance with the design format of the CEB-FIP Model Code and Eurocode2. With the merger of CEB and FIP into fib in 1998, this Task Group became fib TG 9.3 FRP Reinforcement for concrete structures in Commission 9 Reinforcing and Prestressing Materials and Systems. The Task Group consists of about 60 members, representing most European universities, research institutes and industrial companies working in the field of advanced composite reinforcement for concrete structures, as well as corresponding members from Canada, Japan and USA. Meetings are held twice a year and on the research level its work is supported by the EU TMR (European Union Training and Mobility of Researchers) Network "ConFibreCrete”. The work of fib TG 9.3 is performed by five working parties (WP): Material Testing and Characterization (MT&C) Reinforced Concrete (RC) Prestressed Concrete (PC) Externally Bonded Reinforcement (EBR) Marketing and Applications (M&A) This technical report constitutes the work conducted as of to date by the EBR party. This bulletin gives detailed design guidelines on the use of FRP EBR, the practical execution and the quality control, based on the current expertise and state-of-the-art knowledge of the task group members. It is regarded as a progress report since it is not the aim of this report to cover all aspects of RC strengthening with composites. Instead, it focuses on those aspects that form the majority of the design problems. several of the topics presented are subject of ongoing research and development, and the details of some modelling approaches may be subject to future revisions. as knowledge in this field is advancing rapidly, the work of the EBR WP will continue. Inspite of this limit in scope, considerable effort has been made to present a bulletin that is today’s state-of-art in the area of strengthening of concrete structures by means of externally bonded FRP reinforcement.

Download or read book written by and published by World Scientific. This book was released on with total page 771 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ACI Materials Journal written by and published by . This book was released on 2002 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book An experimental and analytical study of prestressed concrete beams made continuous by local post stressing with particular reference to ultimate moment distribution written by Hosagrahar Chandrasekharaiya Visvesvaraya and published by . This book was released on 1956 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Analytical and Experimental Investigation of the Shear Strength of Prestressed Concrete Tee Beams written by K. Van Dalen and published by . This book was released on 1960 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book PCI Journal written by and published by . This book was released on 2009 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Procedures for the Use of Composites in Strengthening of Reinforced Concrete Structures written by Carlo Pellegrino and published by Springer. This book was released on 2015-08-25 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book analyses the current knowledge on structural behaviour of RC elements and structures strengthened with composite materials (experimental, analytical and numerical approaches for EBR and NSM), particularly in relation to the above topics, and the comparison of the predictions of the current available codes/recommendations/guidelines with selected experimental results. The book shows possible critical issues (discrepancies, lacunae, relevant parameters, test procedures, etc.) related to current code predictions or to evaluate their reliability, in order to develop more uniform methods and basic rules for design and control of FRP strengthened RC structures. General problems/critical issues are clarified on the basis of the actual experiences, detect discrepancies in existing codes, lacunae in knowledge and, concerning these identified subjects, provide proposals for improvements. The book will help to contribute to promote and consolidate a more qualified and conscious approach towards rehabilitation and strengthening existing RC structures with composites and their possible monitoring.

Download or read book Reliability Based Analysis of Concrete T Beams Prestressed with Unbonded Tendons written by Ozgur Ozkul and published by . This book was released on 2002 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of 6th International Conference on Civil Engineering and Architecture Vol 2 written by Thomas Kang and published by Springer Nature. This book was released on with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Experimental and Analytical Investigation of the Behaviour of Reinforced Concrete Beams Subjected to Combined Bending and Torsion written by Daniel Rosie Fairbairn and published by . This book was released on 1967 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: