The Experts below are selected from a list of 25464 Experts worldwide ranked by ideXlab platform
Evernden M - One of the best experts on this subject based on the ideXlab platform.
-
Serviceability of non-prismatic concrete beams: Combined-interaction method
Elsevier Ltd., 2019Co-Authors: Tayfur Y, Darby A, Ibell T, Orr J, Evernden MAbstract:© 2019 Elsevier Ltd Interest in the shape optimisation of concrete members is increasing alongside the availability of fabric formwork as a relatively simple technique to cast non-prismatic concrete structures. Research has shown that up 40% of concrete can be saved when shape optimised concrete beams are cast in fabric forms. However, optimisation results in members with non-uniform cross-sections and the resulting beam is less stiff than an equivalent strength prismatic beam. Serviceability, rather than strength, may govern the design of such members and therefore understanding the Serviceability behaviour (deflection and cracking)of shape optimised concrete members becomes is a critical design consideration. There are many methods which can be used to evaluate Serviceability behaviour of reinforced concrete beams, including the full-interaction method, which assumes no slip between the reinforcement and the surrounding concrete, and the partial-interaction method which accounts for slip. The full-interaction method is based on a smeared crack approach and so is unsuited for the prediction of cracking behaviour. The partial-interaction method, on the other hand, assumes that cracks form through bond-stress transfer only. In the case of non-prismatic concrete beams, the cracking capacity varies along the member. Therefore, cracking can occur over extended regions (full and partial bond interaction regions)and so it can be argued that neither of these models is fully suitable for the prediction of deflections and cracking of shape-optimised concrete beams. In this paper, a novel combined-interaction method is, for the first time, presented to predict the Serviceability behaviour of non-prismatic statically determinate concrete beams by simulating both full and partial bond interactions at different cracked and uncracked regions along the length of the member. In order to validate this approach, two non-prismatic simply supported beams were cast and tested. The test results for deflections, crack widths and crack spacings were in good agreement with the predicted results
-
Serviceability of non-prismatic concrete beams: Combined-interaction method
'Organisation for Economic Co-Operation and Development (OECD)', 2019Co-Authors: Tayfur Y, Darby A, Ibell Timothy, Orr John, Evernden MAbstract:Interest in the shape optimisation of concrete members is increasing alongside the availability of fabric formwork as a relatively simple technique to cast non-prismatic concrete structures. Research has shown that up 40% of concrete can be saved when shape optimised concrete beams are cast in fabric forms. However, optimisation results in members with non-uniform cross-sections and the resulting beam is less stiff than an equivalent strength prismatic beam. Serviceability, rather than strength, may govern the design of such members and therefore understanding the Serviceability behaviour (deflection and cracking) of shape optimised concrete members becomes is a critical design consideration. There are many methods which can be used to evaluate Serviceability behaviour of reinforced concrete beams, including the full-interaction method, which assumes no slip between the reinforcement and the surrounding concrete, and the partial-interaction method which accounts for slip. The full-interaction method is based on a smeared crack approach and so is unsuited for the prediction of cracking behaviour. The partial-interaction method, on the other hand, assumes that cracks form through bond-stress transfer only. In the case of non-prismatic concrete beams, the cracking capacity varies along the member. Therefore, cracking can occur over extended regions (full and partial bond interaction regions) and so it can be argued that neither of these models is fully suitable for the prediction of deflections and cracking of shape-optimised concrete beams. In this paper, a novel combined-interaction method is, for the first time, presented to predict the Serviceability behaviour of non-prismatic concrete beams by simulating both full and partial bond interactions at different cracked and uncracked regions along the length of the member. In order to validate this approach, two non-prismatic simply supported beams were cast and tested. The test results for deflections, crack widths and crack spacings were in good agreement with the predicted results
-
Serviceability of non-prismatic concrete beams: Combined-interaction method
Elsevier Ltd., 2019Co-Authors: Tayfur Y, Darby A, Ibell T, Orr J, Evernden MAbstract:Interest in the shape optimisation of concrete members is increasing alongside the availability of fabric formwork as a relatively simple technique to cast non-prismatic concrete structures. Research has shown that up 40% of concrete can be saved when shape optimised concrete beams are cast in fabric forms. However, optimisation results in members with non-uniform cross-sections and the resulting beam is less stiff than an equivalent strength prismatic beam. Serviceability, rather than strength, may govern the design of such members and therefore understanding the Serviceability behaviour (deflection and cracking)of shape optimised concrete members becomes is a critical design consideration. There are many methods which can be used to evaluate Serviceability behaviour of reinforced concrete beams, including the full-interaction method, which assumes no slip between the reinforcement and the surrounding concrete, and the partial-interaction method which accounts for slip. The full-interaction method is based on a smeared crack approach and so is unsuited for the prediction of cracking behaviour. The partial-interaction method, on the other hand, assumes that cracks form through bond-stress transfer only. In the case of non-prismatic concrete beams, the cracking capacity varies along the member. Therefore, cracking can occur over extended regions (full and partial bond interaction regions)and so it can be argued that neither of these models is fully suitable for the prediction of deflections and cracking of shape-optimised concrete beams. In this paper, a novel combined-interaction method is, for the first time, presented to predict the Serviceability behaviour of non-prismatic statically determinate concrete beams by simulating both full and partial bond interactions at different cracked and uncracked regions along the length of the member. In order to validate this approach, two non-prismatic simply supported beams were cast and tested. The test results for deflections, crack widths and crack spacings were in good agreement with the predicted results
Dan M Frangopol - One of the best experts on this subject based on the ideXlab platform.
-
bridge deck replacement for minimum expected cost under multiple reliability constraints
Journal of Structural Engineering-asce, 2004Co-Authors: Mark G Stewart, Allen C Estes, Dan M FrangopolAbstract:The present paper investigates the effect of limit state selection (strength versus Serviceability) on bridge deck life-cycle costs and thus on optimal repair strategies. Such a comparison may then help determine whether safety or functionality (or both) are important criteria when optimizing bridge life-cycle performance and costs. The structural element under consideration is a reinforced concrete bridge deck; namely, a State Highway Bridge in Colorado. Two limit states are considered: ultimate strength and Serviceability. The exceedence of either of the limit states considered herein will result in deck replacement; namely, if the reliability index falls below a target reliability index or if widespread cracking and spalling occurs. The life-cycle cost analysis includes expected replacement costs as well as the random variability of material properties, loads, section dimensions, model errors, chloride penetration, and corrosion rates. Life-cycle costs can then be compared for strength and serviceabili...
Mark G Stewart - One of the best experts on this subject based on the ideXlab platform.
-
bridge deck replacement for minimum expected cost under multiple reliability constraints
Journal of Structural Engineering-asce, 2004Co-Authors: Mark G Stewart, Allen C Estes, Dan M FrangopolAbstract:The present paper investigates the effect of limit state selection (strength versus Serviceability) on bridge deck life-cycle costs and thus on optimal repair strategies. Such a comparison may then help determine whether safety or functionality (or both) are important criteria when optimizing bridge life-cycle performance and costs. The structural element under consideration is a reinforced concrete bridge deck; namely, a State Highway Bridge in Colorado. Two limit states are considered: ultimate strength and Serviceability. The exceedence of either of the limit states considered herein will result in deck replacement; namely, if the reliability index falls below a target reliability index or if widespread cracking and spalling occurs. The life-cycle cost analysis includes expected replacement costs as well as the random variability of material properties, loads, section dimensions, model errors, chloride penetration, and corrosion rates. Life-cycle costs can then be compared for strength and serviceabili...
-
structural safety and Serviceability of concrete bridges subject to corrosion
Journal of Infrastructure Systems, 1998Co-Authors: Mark G Stewart, David V RosowskyAbstract:A structural reliability analysis model is developed to include interaction between transverse cracking, diffusion of chlorides, and corrosion initiation; influence of design specifications on corrosion initiation and propagation; and Serviceability limit states (e.g., spalling). The reliability model is used to evaluate probabilities of structural and Serviceability failures for flexure and spalling limit states, for a typical reinforced concrete bridge continuous slab. Chloride contamination will occur from the application of deicing salts. It was confirmed that the application of deicing salts caused a significant reduction in structural and Serviceability reliabilities; this observation is in agreement with field data of bridge performance. Moreover, the reliability analysis allowed the effect of corrosion to be measured in a quantitative manner. The influence of concrete cover and specified concrete compressive strength was found to be particularly significant on the probability of spalling. The reli...
Ma Erki - One of the best experts on this subject based on the ideXlab platform.
-
prestressed frp sheets for poststrengthening reinforced concrete beams
Journal of Composites for Construction, 2001Co-Authors: R G Wight, Mark F Green, Ma ErkiAbstract:Four large-scale reinforced concrete beams were constructed and tested to investigate the effectiveness of external poststrengthening with prestressed fiber reinforced polymer (FRP) sheets. One of the beams served as a control specimen, another was strengthened with nonprestressed carbon FRP sheets, and the remaining two were strengthened with prestressed carbon FRP sheets. Presented is a method of prestressing multiple layers of the carbon fiber sheets during the application process and the experimental and analytical behavior of the beams under quasi-static loading. Comparisons are made between the control beam, the beam reinforced with nonprestressed carbon FRP sheets, and the beams strengthened with prestressed sheets. Serviceability and ultimate conditions are considered in the theoretical prediction of beam behavior, including the effects of multiple layer prestressing and external loading. The bonding of prestressed FRP sheets to the tensile face of concrete beams improved both the Serviceability a...
Tayfur Y - One of the best experts on this subject based on the ideXlab platform.
-
Serviceability of non-prismatic concrete beams: Combined-interaction method
Elsevier Ltd., 2019Co-Authors: Tayfur Y, Darby A, Ibell T, Orr J, Evernden MAbstract:© 2019 Elsevier Ltd Interest in the shape optimisation of concrete members is increasing alongside the availability of fabric formwork as a relatively simple technique to cast non-prismatic concrete structures. Research has shown that up 40% of concrete can be saved when shape optimised concrete beams are cast in fabric forms. However, optimisation results in members with non-uniform cross-sections and the resulting beam is less stiff than an equivalent strength prismatic beam. Serviceability, rather than strength, may govern the design of such members and therefore understanding the Serviceability behaviour (deflection and cracking)of shape optimised concrete members becomes is a critical design consideration. There are many methods which can be used to evaluate Serviceability behaviour of reinforced concrete beams, including the full-interaction method, which assumes no slip between the reinforcement and the surrounding concrete, and the partial-interaction method which accounts for slip. The full-interaction method is based on a smeared crack approach and so is unsuited for the prediction of cracking behaviour. The partial-interaction method, on the other hand, assumes that cracks form through bond-stress transfer only. In the case of non-prismatic concrete beams, the cracking capacity varies along the member. Therefore, cracking can occur over extended regions (full and partial bond interaction regions)and so it can be argued that neither of these models is fully suitable for the prediction of deflections and cracking of shape-optimised concrete beams. In this paper, a novel combined-interaction method is, for the first time, presented to predict the Serviceability behaviour of non-prismatic statically determinate concrete beams by simulating both full and partial bond interactions at different cracked and uncracked regions along the length of the member. In order to validate this approach, two non-prismatic simply supported beams were cast and tested. The test results for deflections, crack widths and crack spacings were in good agreement with the predicted results
-
Serviceability of non-prismatic concrete beams: Combined-interaction method
'Organisation for Economic Co-Operation and Development (OECD)', 2019Co-Authors: Tayfur Y, Darby A, Ibell Timothy, Orr John, Evernden MAbstract:Interest in the shape optimisation of concrete members is increasing alongside the availability of fabric formwork as a relatively simple technique to cast non-prismatic concrete structures. Research has shown that up 40% of concrete can be saved when shape optimised concrete beams are cast in fabric forms. However, optimisation results in members with non-uniform cross-sections and the resulting beam is less stiff than an equivalent strength prismatic beam. Serviceability, rather than strength, may govern the design of such members and therefore understanding the Serviceability behaviour (deflection and cracking) of shape optimised concrete members becomes is a critical design consideration. There are many methods which can be used to evaluate Serviceability behaviour of reinforced concrete beams, including the full-interaction method, which assumes no slip between the reinforcement and the surrounding concrete, and the partial-interaction method which accounts for slip. The full-interaction method is based on a smeared crack approach and so is unsuited for the prediction of cracking behaviour. The partial-interaction method, on the other hand, assumes that cracks form through bond-stress transfer only. In the case of non-prismatic concrete beams, the cracking capacity varies along the member. Therefore, cracking can occur over extended regions (full and partial bond interaction regions) and so it can be argued that neither of these models is fully suitable for the prediction of deflections and cracking of shape-optimised concrete beams. In this paper, a novel combined-interaction method is, for the first time, presented to predict the Serviceability behaviour of non-prismatic concrete beams by simulating both full and partial bond interactions at different cracked and uncracked regions along the length of the member. In order to validate this approach, two non-prismatic simply supported beams were cast and tested. The test results for deflections, crack widths and crack spacings were in good agreement with the predicted results
-
Serviceability of non-prismatic concrete beams: Combined-interaction method
Elsevier Ltd., 2019Co-Authors: Tayfur Y, Darby A, Ibell T, Orr J, Evernden MAbstract:Interest in the shape optimisation of concrete members is increasing alongside the availability of fabric formwork as a relatively simple technique to cast non-prismatic concrete structures. Research has shown that up 40% of concrete can be saved when shape optimised concrete beams are cast in fabric forms. However, optimisation results in members with non-uniform cross-sections and the resulting beam is less stiff than an equivalent strength prismatic beam. Serviceability, rather than strength, may govern the design of such members and therefore understanding the Serviceability behaviour (deflection and cracking)of shape optimised concrete members becomes is a critical design consideration. There are many methods which can be used to evaluate Serviceability behaviour of reinforced concrete beams, including the full-interaction method, which assumes no slip between the reinforcement and the surrounding concrete, and the partial-interaction method which accounts for slip. The full-interaction method is based on a smeared crack approach and so is unsuited for the prediction of cracking behaviour. The partial-interaction method, on the other hand, assumes that cracks form through bond-stress transfer only. In the case of non-prismatic concrete beams, the cracking capacity varies along the member. Therefore, cracking can occur over extended regions (full and partial bond interaction regions)and so it can be argued that neither of these models is fully suitable for the prediction of deflections and cracking of shape-optimised concrete beams. In this paper, a novel combined-interaction method is, for the first time, presented to predict the Serviceability behaviour of non-prismatic statically determinate concrete beams by simulating both full and partial bond interactions at different cracked and uncracked regions along the length of the member. In order to validate this approach, two non-prismatic simply supported beams were cast and tested. The test results for deflections, crack widths and crack spacings were in good agreement with the predicted results
