The Experts below are selected from a list of 657 Experts worldwide ranked by ideXlab platform
Herbert A. Mang - One of the best experts on this subject based on the ideXlab platform.
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Structural behavior of reinforced concrete segments of tunnel linings strengthened by a steel-concrete composite
Composites Part B: Engineering, 2019Co-Authors: Jiao-long Zhang, Xian Liu, Tian-yu Ren, Yong Yuan, Herbert A. MangAbstract:Abstract Structural defects of existing segmental tunnel linings call for strengthening techniques. This was the motivation for conducting real-scale bearing-capacity tests and computational analysis of strengthened segments by means of a steel-concrete composite (SCC). Two load cases were considered: (i) a Sagging Moment, resulting in intrados and extrados fibers in tension and compression, respectively, and, conversely, (ii) a hogging Moment. The experimental observation has shown that, for both load cases, the strengthened segments failed in a ductile fashion. In case of Sagging Moments, the strengthening effect of the SCC is characterized by the fact that the yield Moment and the post-cracking stiffness of the strengthened segments with a 40-mm-thick SCC are by 393 % and 315 %, respectively, larger than those of the unstrengthened segments. As for hogging Moments, the strengthening effect of the SCC is considerable, albeit less significant than that for Sagging Moments. The derived formulae allow for description of the structural behavior of the strengthened segments and for quantification of the tractions at the interface between the steel shell and the concrete. Two main conclusions are drawn from the computational analyses: (i) Concerning the increase of the strengthening effect, in case of a Sagging Moment, an increase of the thickness of the steel shell is more efficient than that of the new concrete. The converse situation occurs in case of a hogging Moment. (ii) For a Sagging Moment, the interface is in shear-tension, whereas for a hogging Moment it is in shear-compression.
Edoardo Cosenza - One of the best experts on this subject based on the ideXlab platform.
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Non-linear analysis of composite beams under positive bending
Computers & Structures, 1999Co-Authors: Giovanni Fabbrocino, Gaetano Manfredi, Edoardo CosenzaAbstract:Abstract The structural behaviour of steel–concrete composite beams depends on the interaction between the steel beam and the concrete slab. Therefore, the connection largely influences the global behaviour of the beam and its modelling is a key issue in the analysis of these structures. An effective model requires the introduction of an explicit relationship between slip and interaction force given by each connector, which is strongly non-linear. In this paper, a numerical procedure that allows a reliable analysis of the structural behaviour of composite beams subjected to Sagging Moment due to short term loads, both in serviceability and ultimate state, is proposed.
Jiao-long Zhang - One of the best experts on this subject based on the ideXlab platform.
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Structural behavior of reinforced concrete segments of tunnel linings strengthened by a steel-concrete composite
Composites Part B: Engineering, 2019Co-Authors: Jiao-long Zhang, Xian Liu, Tian-yu Ren, Yong Yuan, Herbert A. MangAbstract:Abstract Structural defects of existing segmental tunnel linings call for strengthening techniques. This was the motivation for conducting real-scale bearing-capacity tests and computational analysis of strengthened segments by means of a steel-concrete composite (SCC). Two load cases were considered: (i) a Sagging Moment, resulting in intrados and extrados fibers in tension and compression, respectively, and, conversely, (ii) a hogging Moment. The experimental observation has shown that, for both load cases, the strengthened segments failed in a ductile fashion. In case of Sagging Moments, the strengthening effect of the SCC is characterized by the fact that the yield Moment and the post-cracking stiffness of the strengthened segments with a 40-mm-thick SCC are by 393 % and 315 %, respectively, larger than those of the unstrengthened segments. As for hogging Moments, the strengthening effect of the SCC is considerable, albeit less significant than that for Sagging Moments. The derived formulae allow for description of the structural behavior of the strengthened segments and for quantification of the tractions at the interface between the steel shell and the concrete. Two main conclusions are drawn from the computational analyses: (i) Concerning the increase of the strengthening effect, in case of a Sagging Moment, an increase of the thickness of the steel shell is more efficient than that of the new concrete. The converse situation occurs in case of a hogging Moment. (ii) For a Sagging Moment, the interface is in shear-tension, whereas for a hogging Moment it is in shear-compression.
Ehab El-salakawy - One of the best experts on this subject based on the ideXlab platform.
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Behavior of Glass Fiber–Reinforced Polymer Reinforced Concrete Continuous T-Beams
Journal of Composites for Construction, 2017Co-Authors: S. M. Hasanur Rahman, Karam Mahmoud, Ehab El-salakawyAbstract:AbstractIn this paper, test results of six large-scale glass fiber–reinforced polymer (GFRP) RC continuous T-beams are presented. The test specimens include one steel RC beam to serve as reference, one GFRP RC beam designed to meet the serviceability criteria at the service load level calculated for the reference beam, and four GFRP RC beams designed to achieve the same theoretical ultimate load of the reference beam. The test variables included the assumed percentage of Moment redistribution, the spacing of lateral reinforcement in flange, and the arrangement of shear reinforcement. The test results showed that Moment redistribution from the hogging to the Sagging Moment region occurred in GFRP RC beams with T-sections and that a small spacing of stirrups enhanced the Moment redistribution percentage. In addition, decreasing the spacing of lateral reinforcement in the flange improved the Moment redistribution through enhancing the stiffness of the Sagging Moment region.
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Shear Strength of GFRP-Reinforced Concrete Continuous Beams with Minimum Transverse Reinforcement
Journal of Composites for Construction, 2014Co-Authors: Karam Mahmoud, Ehab El-salakawyAbstract:AbstractThis paper investigates the shear behavior of continuous concrete beams reinforced with glass fiber–reinforced polymer (GFRP) bars and stirrups. A total of six beams, with 200×300 mm rectangular cross section and continuous over two spans of 2,800 mm each, were constructed and tested. Three main variables, namely, concrete strength, longitudinal reinforcement ratio, and transverse shear-reinforcement ratio, were investigated. Two beams were without transverse reinforcement to evaluate the concrete contribution to the shear strength and four beams had GFRP stirrups to examine the minimum shear-reinforcement contribution to the shear strength. All test specimens were designed to satisfy an assumed 20% Moment redistribution. It was observed that all test specimens failed in shear near the interior support after significant Moment redistribution from hogging Moment to Sagging Moment regions. In addition, the test results were compared with the predictions of the CSA-S806-12, CSA-S6-06, and ACI 440.1R-06.
Marian Abramowicz - One of the best experts on this subject based on the ideXlab platform.
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Premature destruction of two-span RC beams exposed to high temperature caused by a redistribution of shear forces
Vilnius Gedinimas Technical University, 2017Co-Authors: Robert Kowalski, Michał Głowacki, Marian AbramowiczAbstract:When multi-span RC elements are exposed to fire one usually observes a yielding of span cross-sections while a safety reserve of support cross-sections is still significant. Due to this phenomenon a redistribution of bending Moments occurs and the values of Sagging Moment in span cross-sections decrease while the values of hogging Moment in support cross-sections increase. This paper shows the results of tests conducted on two-span RC beams in a situation when only one span has been exposed to high temperature from the bottom. The beams were 12×16 cm in their cross-section. The length of the span was 165 cm. The load has been applied by two forces put on each span. The beams were made of C25/30 concrete with siliceous aggregate. As a result of significant stiffness decrease of the heated span, redistribution of shear forces and bending Moment occurs. Due to this redistribution the tested beams were prematurely damaged due to exhaust of the shear load bearing capacity in the middle part of the beam span where there was no transverse reinforcement. First published online: 27 Jun 201
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Premature destruction of two-span RC beams exposed to high temperature caused by a redistribution of shear forces
JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT, 2016Co-Authors: Robert Kowalski, Michał Głowacki, Marian AbramowiczAbstract:AbstractWhen multi-span RC elements are exposed to fire one usually observes a yielding of span cross-sections while a safety reserve of support cross-sections is still significant. Due to this phenomenon a redistribution of bending Moments occurs and the values of Sagging Moment in span cross-sections decrease while the values of hogging Moment in support cross-sections increase. This paper shows the results of tests conducted on two-span RC beams in a situation when only one span has been exposed to high temperature from the bottom. The beams were 12×16 cm in their crosssection. The length of the span was 165 cm. The load has been applied by two forces put on each span. The beams were made of C25/30 concrete with siliceous aggregate. As a result of significant stiffness decrease of the heated span, redistribution of shear forces and bending Moment occurs. Due to this redistribution the tested beams were prematurely damaged due to exhaust of the shear load bearing capacity in the middle part of the beam ...
