The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Peter W Jones - One of the best experts on this subject based on the ideXlab platform.
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flexural strain and crack width measurement of steel fibre reinforced concrete by optical grid and electrical gauge methods
Cement and Concrete Research, 2001Co-Authors: P J Robins, Simon A Austin, Jim H Chandler, Peter W JonesAbstract:A research programme is discussed, which has investigated the fracture of steel-fibre-reinforced sprayed concrete under flexural loading, with the aim of developing a Stress-Block model to predict flexural behaviour in the form of a load–deflection response. This paper reports the work associated with establishing the strain and crack width profiles in relation to mid-span beam deflection. A strain analysis technique is described, which combines the use of electrical strain gauges with a semiautomated grid method (using digital image processing) for measuring and monitoring the strain and crack width profile over the depth of a fibre-reinforced beam during a flexural test. This novel strain analysis technique has established strain/crack width data, which forms a key part of a Stress-Block approach for predicting residual flexural strength, an essential requirement of a much needed design rationale for steel-fibre-reinforced concrete.
P J Robins - One of the best experts on this subject based on the ideXlab platform.
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predicting the flexural load deflection response of steel fibre reinforced concrete from strain crack width fibre pull out and distribution data
Materials and Structures, 2008Co-Authors: Peter A Jones, Simon A Austin, P J RobinsAbstract:A semi-analytical model is presented, based on conventional principles of mechanics, to predict the flexure behaviour of steel fibre reinforced concrete. The model uses a Stress-Block approach to represent the Stresses that develop at a cracked section by three discrete Stress zones: (a) a compressive zone; (b) an uncracked tensile zone; and (c) a cracked tensile zone. It is further shown that the Stress-Block, and hence flexural behaviour, is a function of five principal parameters: compressive Stress–strain relation; tensile Stress–strain relation; fibre pull-out behaviour; the number and distribution of fibres across the cracked section in terms of their positions, orientations and embedment lengths; and the strain/crack-width profile in relation to the deflection of the beam. An experimental investigation was undertaken on both cast and sprayed specimens to obtain relationships for use in the model. The results of the study showed a reasonable agreement between the model predictions and experimental results. However, the accuracy of the model is probably unacceptable for it to be currently used in design. A subsequent analysis highlighted the single fibre pull-out test and the sensitivity of the strain analysis tests as being the main cause of the discrepancies.
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flexural strain and crack width measurement of steel fibre reinforced concrete by optical grid and electrical gauge methods
Cement and Concrete Research, 2001Co-Authors: P J Robins, Simon A Austin, Jim H Chandler, Peter W JonesAbstract:A research programme is discussed, which has investigated the fracture of steel-fibre-reinforced sprayed concrete under flexural loading, with the aim of developing a Stress-Block model to predict flexural behaviour in the form of a load–deflection response. This paper reports the work associated with establishing the strain and crack width profiles in relation to mid-span beam deflection. A strain analysis technique is described, which combines the use of electrical strain gauges with a semiautomated grid method (using digital image processing) for measuring and monitoring the strain and crack width profile over the depth of a fibre-reinforced beam during a flexural test. This novel strain analysis technique has established strain/crack width data, which forms a key part of a Stress-Block approach for predicting residual flexural strength, an essential requirement of a much needed design rationale for steel-fibre-reinforced concrete.
Simon A Austin - One of the best experts on this subject based on the ideXlab platform.
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predicting the flexural load deflection response of steel fibre reinforced concrete from strain crack width fibre pull out and distribution data
Materials and Structures, 2008Co-Authors: Peter A Jones, Simon A Austin, P J RobinsAbstract:A semi-analytical model is presented, based on conventional principles of mechanics, to predict the flexure behaviour of steel fibre reinforced concrete. The model uses a Stress-Block approach to represent the Stresses that develop at a cracked section by three discrete Stress zones: (a) a compressive zone; (b) an uncracked tensile zone; and (c) a cracked tensile zone. It is further shown that the Stress-Block, and hence flexural behaviour, is a function of five principal parameters: compressive Stress–strain relation; tensile Stress–strain relation; fibre pull-out behaviour; the number and distribution of fibres across the cracked section in terms of their positions, orientations and embedment lengths; and the strain/crack-width profile in relation to the deflection of the beam. An experimental investigation was undertaken on both cast and sprayed specimens to obtain relationships for use in the model. The results of the study showed a reasonable agreement between the model predictions and experimental results. However, the accuracy of the model is probably unacceptable for it to be currently used in design. A subsequent analysis highlighted the single fibre pull-out test and the sensitivity of the strain analysis tests as being the main cause of the discrepancies.
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flexural strain and crack width measurement of steel fibre reinforced concrete by optical grid and electrical gauge methods
Cement and Concrete Research, 2001Co-Authors: P J Robins, Simon A Austin, Jim H Chandler, Peter W JonesAbstract:A research programme is discussed, which has investigated the fracture of steel-fibre-reinforced sprayed concrete under flexural loading, with the aim of developing a Stress-Block model to predict flexural behaviour in the form of a load–deflection response. This paper reports the work associated with establishing the strain and crack width profiles in relation to mid-span beam deflection. A strain analysis technique is described, which combines the use of electrical strain gauges with a semiautomated grid method (using digital image processing) for measuring and monitoring the strain and crack width profile over the depth of a fibre-reinforced beam during a flexural test. This novel strain analysis technique has established strain/crack width data, which forms a key part of a Stress-Block approach for predicting residual flexural strength, an essential requirement of a much needed design rationale for steel-fibre-reinforced concrete.
Jim H Chandler - One of the best experts on this subject based on the ideXlab platform.
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flexural strain and crack width measurement of steel fibre reinforced concrete by optical grid and electrical gauge methods
Cement and Concrete Research, 2001Co-Authors: P J Robins, Simon A Austin, Jim H Chandler, Peter W JonesAbstract:A research programme is discussed, which has investigated the fracture of steel-fibre-reinforced sprayed concrete under flexural loading, with the aim of developing a Stress-Block model to predict flexural behaviour in the form of a load–deflection response. This paper reports the work associated with establishing the strain and crack width profiles in relation to mid-span beam deflection. A strain analysis technique is described, which combines the use of electrical strain gauges with a semiautomated grid method (using digital image processing) for measuring and monitoring the strain and crack width profile over the depth of a fibre-reinforced beam during a flexural test. This novel strain analysis technique has established strain/crack width data, which forms a key part of a Stress-Block approach for predicting residual flexural strength, an essential requirement of a much needed design rationale for steel-fibre-reinforced concrete.
Joh Mande - One of the best experts on this subject based on the ideXlab platform.
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Stress Block parameters for unconfined and confined concrete based on a unified Stress strain model
Journal of Structural Engineering-asce, 2011Co-Authors: Madhu M Karthik, Joh MandeAbstract:Equations to obtain equivalent rectangular Stress-Block parameters for unconfined and confined concrete are derived for rapid (hand) analysis and design purposes. To overcome a shortcoming of existing commonly used Stress-strain models that are not easy to integrate, a new Stress-strain model is proposed and validated for a wide range of concrete strengths and confining Stresses. The efficacy of the equivalent rectangular Stress-Block parameters is demonstrated for hand calculations in predicting key moment-curvature results for a confined concrete column. Results are compared with those obtained from a computational fiber-element analysis using the proposed Stress-strain model and another widely used existing model; good agreement between the two is observed.
