The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Deric J. Oehlers - One of the best experts on this subject based on the ideXlab platform.
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Debonding of steel plates adhesively bonded to the Compression Faces of RC beams
Construction and Building Materials, 2005Co-Authors: M.s. Mohamed Ali, Deric J. Oehlers, Mark A. BradfordAbstract:Abstract Reinforced concrete beams in buildings and bridges are increasingly being retrofitted by adhesively bonding steel or FRP plates to their tension Faces. However, tests have shown that tension Face plates are prone to premature debonding. One way of preventing or inhibiting debonding of tension Face plates in continuous beams is to extend the plate-ends past the points of contraflexure into the Compression Faces. In this paper: it is shown that Compression Face plates are less likely to debond than tension Face plates; results of thirteen tests on debonding due to vertical shear forces (critical diagonal crack debonding) and curvature (flexural end plate debonding) are described; and critical diagonal crack and flexural end plate debonding models are developed for Compression Face plates that can be used to ensure that beams with tension Face plates that are extended into the Compression Faces do not debond prematurely.
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a structural engineering approach to adhesive bonding longitudinal plates to rc beams and slabs
Composites Part A-applied Science and Manufacturing, 2003Co-Authors: Deric J. Oehlers, S M ParkAbstract:Retrofitting by plating structures has been found to be very efficient. However, tests have shown that externally bonded longitudinal plates are prone to premature debonding. Furthermore, a comprehensive study of published research has also shown that there can be large discrepancies between debonding mathematical models and tests. To overcome this problem and to allow structural engineers to adhesively bond plates with safety and efficiently, a structural engineering approach is suggested whereby many of the debonding mechanisms can be prevented by judicious detailing; this approach can be applied to tension Face plates, Compression Face plates, side plates, U-sectioned plates, and angle-sectioned plates. Four continuous reinforced concrete beams have been retrofitted with adhesively bonded longitudinal plates and tested in order to illustrate this design approach, to directly compare the performance of longitudinal side plates with longitudinal tension Face plates, to compare FRP plating with steel plating, and in particular to illustrate the effect of debonding on the sectional ductility of longitudinally plated continuous RC beams.
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Improving the strength and ductility of rectangular reinforced concrete columns through composite partial interaction: Tests
Journal of Structural Engineering, 2003Co-Authors: Michael C. Griffith, Deric J. OehlersAbstract:A new structural approach that uses composite partial interaction to improve the strength and ductility of rectangular reinforced concrete columns has been studied experimentally. By increasing the compressive resistance of concrete columns, through composite partial interaction such as by bolting a steel plate to the Compression Face of a column, this new composite action approach is shown to successfully delay concrete crushing in the plastic hinge zone. The experimental results confirm theoretical predictions that composite partial interaction can be used to increase either the strength or ductility (or both) of concrete columns. The paper also briefly describes a design procedure for the retrofit strategy to achieve a specified displacement, or interstory drift.
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Strengthening of reinforced concrete bridges by external plates
2002Co-Authors: Msm Ali, Deric J. OehlersAbstract:Experience in India has shown that bonding plates to the surFaces of reinforced concrete beams and slabs is an inexpensive, unobtrusive and efficient method for strengthening and stiffening. Steel plates or fibre-reinforced plastic plates with virtually any mechanical property can be used. These plates may be bolted and/or adhesively bonded to beams. They may be attached to the tension Face, Compression Face or sides of the beam, or flat plates, angle sections or channel sections may be used. The choice is governed by consideration of durability, strength, stiffness and ductility. Different failure mechanisms are illustrated and factors relevant to the selection of methods are considered using two bridges in Australia as examples.
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Interaction between Flexure and Shear on the Debonding of RC Beams Retrofitted with Compression Face Plates
Advances in Structural Engineering, 2002Co-Authors: M.s. Mohamed Ali, Deric J. Oehlers, Mark A. BradfordAbstract:Steel and FRP plating reinforced concrete structures is increasingly being used for retrofitting. Plates can be bonded to any surFace of a beam or slab, although it is common practice to adhesively bond plates to the tension Faces. The addition of these tension Face plates reduces the sectional ductility of the beam. Furthermore, these tension Face plates are prone to premature debonding because the stress concentrations induced by these plates overlap with those induced by the tension reinforcing bars adjacent to the plate. Solutions to these two problems, which are the subject of this paper, consist of: adhesively bonding plates to the Compression Faces to counterbalance the tension Face plates and, hence, improve the beam sectional ductility; and to extend the tension Face plates, in continuous beams, past the points of contraflexure so that they terminate in a Compression Face. In this paper, eleven new tests on 340 mm deep beams are presented that show that Compression Face plates are less prone to d...
Nan Jiang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication, properties and failure of 3D integrated woven spacer composites with thickened Face sheets
Materials Letters, 2015Co-Authors: Chuang-qi Zhao, Nan Jiang, Lei JiangAbstract:Abstract In this letter, 3D integrated woven spacer composites with thickened Face sheets were fabricated successfully by 3D integrated woven technology and VARIM process. The three-point bending properties and failure mechanism were first analyzed to evaluate the effect of thickened Face sheets. The results show that the thickness of Face sheets is an important parameter influencing the mechanical properties of 3D integrated woven spacer composite. The bending load-bearing ability is improved significantly than that of composite without thickened Face. Moreover, the strength of thickened Face sheets dominates the failure of composite, and the destruction is a gradual process from external layers of the Compression Face to the interior “8”-shaped core layers. The better mechanical properties of this new composite indicate it has a good potential application in many engineering fields.
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Experimental study on the bending properties and failure mechanism of 3D integrated woven spacer composites at room and cryogenic temperature
Composite Structures, 2014Co-Authors: Dian-sen Li, Chuang-qi Zhao, Lei Jiang, Nan JiangAbstract:Abstract Three-point bending tests at room and liquid nitrogen temperature (as low as −196 °C) are conducted on the 3D integrated woven spacer composites with different core heights. Macrofracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that the bending properties at liquid nitrogen temperature are improved significantly than those at room temperature. Meanwhile, the bending properties both at room and liquid nitrogen temperature can be affected greatly by the core height. Moreover, the damage and failure patterns of composites vary with the core height and test temperature. At room temperature, three typical failure mechanism have been obtained for composites with different core heights. At liquid nitrogen temperature, the composites show gradual failure process which extends from the external layers of the Compression Face to the interior core layers. Furthermore, the brittle failure feature becomes more obvious and the interfacial adhesion capacity is enhanced significantly.
Lei Jiang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication, properties and failure of 3D integrated woven spacer composites with thickened Face sheets
Materials Letters, 2015Co-Authors: Chuang-qi Zhao, Nan Jiang, Lei JiangAbstract:Abstract In this letter, 3D integrated woven spacer composites with thickened Face sheets were fabricated successfully by 3D integrated woven technology and VARIM process. The three-point bending properties and failure mechanism were first analyzed to evaluate the effect of thickened Face sheets. The results show that the thickness of Face sheets is an important parameter influencing the mechanical properties of 3D integrated woven spacer composite. The bending load-bearing ability is improved significantly than that of composite without thickened Face. Moreover, the strength of thickened Face sheets dominates the failure of composite, and the destruction is a gradual process from external layers of the Compression Face to the interior “8”-shaped core layers. The better mechanical properties of this new composite indicate it has a good potential application in many engineering fields.
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Experimental study on the bending properties and failure mechanism of 3D integrated woven spacer composites at room and cryogenic temperature
Composite Structures, 2014Co-Authors: Dian-sen Li, Chuang-qi Zhao, Lei Jiang, Nan JiangAbstract:Abstract Three-point bending tests at room and liquid nitrogen temperature (as low as −196 °C) are conducted on the 3D integrated woven spacer composites with different core heights. Macrofracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that the bending properties at liquid nitrogen temperature are improved significantly than those at room temperature. Meanwhile, the bending properties both at room and liquid nitrogen temperature can be affected greatly by the core height. Moreover, the damage and failure patterns of composites vary with the core height and test temperature. At room temperature, three typical failure mechanism have been obtained for composites with different core heights. At liquid nitrogen temperature, the composites show gradual failure process which extends from the external layers of the Compression Face to the interior core layers. Furthermore, the brittle failure feature becomes more obvious and the interfacial adhesion capacity is enhanced significantly.
Chuang-qi Zhao - One of the best experts on this subject based on the ideXlab platform.
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Fabrication, properties and failure of 3D integrated woven spacer composites with thickened Face sheets
Materials Letters, 2015Co-Authors: Chuang-qi Zhao, Nan Jiang, Lei JiangAbstract:Abstract In this letter, 3D integrated woven spacer composites with thickened Face sheets were fabricated successfully by 3D integrated woven technology and VARIM process. The three-point bending properties and failure mechanism were first analyzed to evaluate the effect of thickened Face sheets. The results show that the thickness of Face sheets is an important parameter influencing the mechanical properties of 3D integrated woven spacer composite. The bending load-bearing ability is improved significantly than that of composite without thickened Face. Moreover, the strength of thickened Face sheets dominates the failure of composite, and the destruction is a gradual process from external layers of the Compression Face to the interior “8”-shaped core layers. The better mechanical properties of this new composite indicate it has a good potential application in many engineering fields.
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Experimental study on the bending properties and failure mechanism of 3D integrated woven spacer composites at room and cryogenic temperature
Composite Structures, 2014Co-Authors: Dian-sen Li, Chuang-qi Zhao, Lei Jiang, Nan JiangAbstract:Abstract Three-point bending tests at room and liquid nitrogen temperature (as low as −196 °C) are conducted on the 3D integrated woven spacer composites with different core heights. Macrofracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that the bending properties at liquid nitrogen temperature are improved significantly than those at room temperature. Meanwhile, the bending properties both at room and liquid nitrogen temperature can be affected greatly by the core height. Moreover, the damage and failure patterns of composites vary with the core height and test temperature. At room temperature, three typical failure mechanism have been obtained for composites with different core heights. At liquid nitrogen temperature, the composites show gradual failure process which extends from the external layers of the Compression Face to the interior core layers. Furthermore, the brittle failure feature becomes more obvious and the interfacial adhesion capacity is enhanced significantly.
Mark A. Bradford - One of the best experts on this subject based on the ideXlab platform.
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Debonding of steel plates adhesively bonded to the Compression Faces of RC beams
Construction and Building Materials, 2005Co-Authors: M.s. Mohamed Ali, Deric J. Oehlers, Mark A. BradfordAbstract:Abstract Reinforced concrete beams in buildings and bridges are increasingly being retrofitted by adhesively bonding steel or FRP plates to their tension Faces. However, tests have shown that tension Face plates are prone to premature debonding. One way of preventing or inhibiting debonding of tension Face plates in continuous beams is to extend the plate-ends past the points of contraflexure into the Compression Faces. In this paper: it is shown that Compression Face plates are less likely to debond than tension Face plates; results of thirteen tests on debonding due to vertical shear forces (critical diagonal crack debonding) and curvature (flexural end plate debonding) are described; and critical diagonal crack and flexural end plate debonding models are developed for Compression Face plates that can be used to ensure that beams with tension Face plates that are extended into the Compression Faces do not debond prematurely.
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Interaction between Flexure and Shear on the Debonding of RC Beams Retrofitted with Compression Face Plates
Advances in Structural Engineering, 2002Co-Authors: M.s. Mohamed Ali, Deric J. Oehlers, Mark A. BradfordAbstract:Steel and FRP plating reinforced concrete structures is increasingly being used for retrofitting. Plates can be bonded to any surFace of a beam or slab, although it is common practice to adhesively bond plates to the tension Faces. The addition of these tension Face plates reduces the sectional ductility of the beam. Furthermore, these tension Face plates are prone to premature debonding because the stress concentrations induced by these plates overlap with those induced by the tension reinforcing bars adjacent to the plate. Solutions to these two problems, which are the subject of this paper, consist of: adhesively bonding plates to the Compression Faces to counterbalance the tension Face plates and, hence, improve the beam sectional ductility; and to extend the tension Face plates, in continuous beams, past the points of contraflexure so that they terminate in a Compression Face. In this paper, eleven new tests on 340 mm deep beams are presented that show that Compression Face plates are less prone to d...