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Bhushan Lal Karihaloo - One of the best experts on this subject based on the ideXlab platform.
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proportioning of self compacting concrete mixes based on target Plastic Viscosity and compressive strength part ii experimental validation
Journal of Sustainable Cement-Based Materials, 2016Co-Authors: Mohammed Abo S Dhaheer, Bhushan Lal Karihaloo, Muna M Alrubaye, Wajde S Alyhya, Sivakumar KulasegaramAbstract:A companion paper by the authors described the mix design procedure and gave several examples on the use of the design charts. This paper is concerned with the experimental validation of the mix design procedure on a series of SCC mixes in both the fresh and hardened states. A series of SCC mixes that contained different volumetric ratios of paste to solid phases were prepared using the design charts. All these mixes were extensively tested in the fresh state using the slump cone, J-ring, L-box, and V-funnel apparatus. These tests proved conclusively the validity of the mix proportioning method in the sense that all the mixes satisfied the self-compacting criteria and achieved the desired target Plastic Viscosity and compressive strength.
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proportioning of self compacting concrete mixes based on target Plastic Viscosity and compressive strength part i mix design procedure
Journal of Sustainable Cement-Based Materials, 2016Co-Authors: Mohammed Abo S Dhaheer, Bhushan Lal Karihaloo, Muna M Alrubaye, Wajde S Alyhya, Sivakumar KulasegaramAbstract:A companion paper by the authors described the mix design procedure and gave several examples on the use of the design charts. This paper is concerned with the experimental validation of the mix design procedure on a series of SCC mixes in both the fresh and hardened states. A series of SCC mixes that contained different volumetric ratios of paste to solid phases were prepared using the design charts. All these mixes were extensively tested in the fresh state using the slump cone, J-ring, L-box, and V-funnel apparatus. These tests proved conclusively the validity of the mix proportioning method in the sense that all the mixes satisfied the self-compacting criteria and achieved the desired target Plastic Viscosity and compressive strength.
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Proportioning of self–compacting concrete mixes based on target Plastic Viscosity and compressive strength: Part I - mix design procedure
Journal of Sustainable Cement-Based Materials, 2015Co-Authors: Mohammed Abo S Dhaheer, Bhushan Lal Karihaloo, Wajde S Alyhya, Muna M. Al-rubaye, Sivakumar KulasegaramAbstract:A companion paper by the authors described the mix design procedure and gave several examples on the use of the design charts. This paper is concerned with the experimental validation of the mix design procedure on a series of SCC mixes in both the fresh and hardened states. A series of SCC mixes that contained different volumetric ratios of paste to solid phases were prepared using the design charts. All these mixes were extensively tested in the fresh state using the slump cone, J-ring, L-box, and V-funnel apparatus. These tests proved conclusively the validity of the mix proportioning method in the sense that all the mixes satisfied the self-compacting criteria and achieved the desired target Plastic Viscosity and compressive strength.
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Accurate estimation of rheological properties of self-compacting concrete
2015Co-Authors: Bhushan Lal Karihaloo, Sivakumar Kulasegaram, Firas BadryAbstract:We describe how the rheological properties of self-compacting concrete (SCC), namely its yield stress and Plastic Viscosity can be accurately estimated. Currently these properties are measured using a rheometer, but these measurements are unreliable because they are very different depending on the rheometer used. This is to do with the heterogeneous nature of the SCC mix. To get a reliable estimate of these properties, a micromechanical procedure is described for estimating the Plastic Viscosity of the heterogeneous mix from the Plastic Viscosity of the homogeneous viscous paste and the mix composition. The yield stress on the other hand is estimated in an inverse manner from the measured t500 and flow spread of the mix in a cone flow test using the three-dimensional smooth particle hydrodynamics (SPH) method for simulating the flow of SCC.
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prediction of the Plastic Viscosity of self compacting steel fibre reinforced concrete
Cement and Concrete Research, 2009Co-Authors: Akbar Ghanbari, Bhushan Lal KarihalooAbstract:Micromechanical constitutive models are used to predict the Plastic Viscosity of self-compacting steel fibre reinforced concrete (SCFRC) from the measured Plastic Viscosity of the paste. The concrete is regarded as a two-phase composite in which the solid phase is suspended in a viscous liquid phase. The liquid matrix phase consists of cement, water and any Viscosity modifying agent (VMA) to which the solids (fine and coarse aggregates and fibres) are added in succession. The predictions are shown to correlate very well with available experimental data. Comments are made on the practical usefulness of the predicted Plastic Viscosity in simulating the flow of SCFRC.
Akbar Ghanbari - One of the best experts on this subject based on the ideXlab platform.
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Development of self-compacting high and ultra high performance concretes with and without steel fibres
Cement & Concrete Composites, 2012Co-Authors: Rola Deeb, Akbar Ghanbari, B. L. KarihalooAbstract:This paper describes the steps taken to develop self-compacting high and ultra high-performance concretes with and without steel fibres. For the self-compacting concrete mixes without steel fibres the fulfilment of flow and cohesiveness criteria are sufficient for the mix design. However, for the design of self-compacting concrete mixes with steel fibres it is found, as expected, that they must additionally meet the passing ability criterion. The Plastic Viscosity of the mixes with and without steel fibres has been estimated from the known Plastic Viscosity of the cement paste using simple micromechanical relations.
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prediction of the Plastic Viscosity of self compacting steel fibre reinforced concrete
Cement and Concrete Research, 2009Co-Authors: Akbar Ghanbari, Bhushan Lal KarihalooAbstract:Micromechanical constitutive models are used to predict the Plastic Viscosity of self-compacting steel fibre reinforced concrete (SCFRC) from the measured Plastic Viscosity of the paste. The concrete is regarded as a two-phase composite in which the solid phase is suspended in a viscous liquid phase. The liquid matrix phase consists of cement, water and any Viscosity modifying agent (VMA) to which the solids (fine and coarse aggregates and fibres) are added in succession. The predictions are shown to correlate very well with available experimental data. Comments are made on the practical usefulness of the predicted Plastic Viscosity in simulating the flow of SCFRC.
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Prediction of the Plastic Viscosity of self-compacting steel fibre reinforced concrete
Cement and Concrete Research, 2009Co-Authors: Akbar Ghanbari, Bhushan Lal KarihalooAbstract:Micromechanical constitutive models are used to predict the Plastic Viscosity of self-compacting steel fibre reinforced concrete (SCFRC) from the measured Plastic Viscosity of the paste. The concrete is regarded as a two-phase composite in which the solid phase is suspended in a viscous liquid phase. The liquid matrix phase consists of cement, water and any Viscosity modifying agent (VMA) to which the solids (fine and coarse aggregates and fibres) are added in succession. The predictions are shown to correlate very well with available experimental data. Comments are made on the practical usefulness of the predicted Plastic Viscosity in simulating the flow of SCFRC. © 2009 Elsevier Ltd. All rights reserved.
Christof Schrofl - One of the best experts on this subject based on the ideXlab platform.
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effect of superabsorbent polymers saps on rheological properties of fresh cement based mortars development of yield stress and Plastic Viscosity over time
Cement and Concrete Research, 2015Co-Authors: Viktor Mechtcherine, Egor Secrieru, Christof SchroflAbstract:Abstract Superabsorbent polymers (SAPs) are a new, promising, multipurpose chemical admixture for concrete. This article addresses the rheological behaviour of fresh, cement-based mortars modified with SAP. Two types of SAP with differing water absorption and desorption kinetics were used. Additionally, for one the grading was varied. Three reference mortars were investigated. The rheological properties of these fresh mortars were tested for 90 min by continuous flow rheometry. It was found that the distinct kinetics of water uptake inherent in the SAP samples, as governed by their particular chemical structures, is the major factor that governs the rheological properties of fresh mortar. Furthermore, the grading of SAP distinctly affects the development of yield stress and Plastic Viscosity over time. The particular effects of specific SAP addition on the rheological characteristics of a mortar depend on the water-to-binder ratio, the dosage of superPlasticizer, and the dosage of silica fume, if present.
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Effect of superabsorbent polymers (SAPs) on rheological properties of fresh cement-based mortars — Development of yield stress and Plastic Viscosity over time
Cement and Concrete Research, 2014Co-Authors: Viktor Mechtcherine, Egor Secrieru, Christof SchroflAbstract:Abstract Superabsorbent polymers (SAPs) are a new, promising, multipurpose chemical admixture for concrete. This article addresses the rheological behaviour of fresh, cement-based mortars modified with SAP. Two types of SAP with differing water absorption and desorption kinetics were used. Additionally, for one the grading was varied. Three reference mortars were investigated. The rheological properties of these fresh mortars were tested for 90 min by continuous flow rheometry. It was found that the distinct kinetics of water uptake inherent in the SAP samples, as governed by their particular chemical structures, is the major factor that governs the rheological properties of fresh mortar. Furthermore, the grading of SAP distinctly affects the development of yield stress and Plastic Viscosity over time. The particular effects of specific SAP addition on the rheological characteristics of a mortar depend on the water-to-binder ratio, the dosage of superPlasticizer, and the dosage of silica fume, if present.
S E Chidiac - One of the best experts on this subject based on the ideXlab platform.
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rheological models for predicting Plastic Viscosity and yield stress of fresh concrete
Cement and Concrete Research, 2013Co-Authors: F Mahmoodzadeh, S E ChidiacAbstract:Abstract Merits of the rheological models that have been proposed in the literature for characterizing the flow behavior of fresh concrete and concentrated suspensions are briefly assessed. New rheological models which employ the cell method are proposed for predicting the Plastic Viscosity and yield stress of fresh concrete on the basis of the mixture composition. Cell method, a geometric description, is mathematically proven to be representative of fresh concrete. Model predictions are evaluated using two experimental programs that use different testing apparatus, material properties and mixture composition. Statistical evaluation of the models reveals that their predictions are a good fit, display the same trend as the experimental data, are unbiased, yield good estimate, and do not systematically deviate from the measured values.
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Plastic Viscosity of fresh concrete – A critical review of predictions methods
Cement & Concrete Composites, 2009Co-Authors: S E Chidiac, F MahmoodzadehAbstract:Abstract Rheological properties of fresh concrete, namely Plastic Viscosity and yield stress, are critical for the concrete industry because they affect placement and workability. Moreover, these rheological properties influence the productivity and quality of concrete, including mechanical properties and durability. Therefore proper characterization of these properties is needed to control the quality of fresh concrete and ensure sustainability of concrete structures. Fundamental and phenomenological rheological models have been proposed in the literature for characterizing the behaviour of fresh concrete. Establishing a model for predicting the Plastic Viscosity of concrete based on its composition will be extremely valuable for the concrete industry. This paper provides a critical review of the most prevailing models in concrete technology as well as models proposed in the literature for predicting the Plastic Viscosity of dense suspensions to a total of eight models. Review has revealed that Mahmoodzadeh and Chidiac models based on the cell method provides a higher degree of correlation to the experimental data as well as a more consistent and reliable predictions in comparison to the models currently proposed in the literature for concrete and/or dense suspensions.
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Plastic Viscosity of fresh concrete a critical review of predictions methods
Cement & Concrete Composites, 2009Co-Authors: S E Chidiac, F MahmoodzadehAbstract:Abstract Rheological properties of fresh concrete, namely Plastic Viscosity and yield stress, are critical for the concrete industry because they affect placement and workability. Moreover, these rheological properties influence the productivity and quality of concrete, including mechanical properties and durability. Therefore proper characterization of these properties is needed to control the quality of fresh concrete and ensure sustainability of concrete structures. Fundamental and phenomenological rheological models have been proposed in the literature for characterizing the behaviour of fresh concrete. Establishing a model for predicting the Plastic Viscosity of concrete based on its composition will be extremely valuable for the concrete industry. This paper provides a critical review of the most prevailing models in concrete technology as well as models proposed in the literature for predicting the Plastic Viscosity of dense suspensions to a total of eight models. Review has revealed that Mahmoodzadeh and Chidiac models based on the cell method provides a higher degree of correlation to the experimental data as well as a more consistent and reliable predictions in comparison to the models currently proposed in the literature for concrete and/or dense suspensions.
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Plastic Viscosity of fresh concrete - A critical review of predictions methods
Cement and Concrete Composites, 2009Co-Authors: S E Chidiac, F MahmoodzadehAbstract:Rheological properties of fresh concrete, namely Plastic Viscosity and yield stress, are critical for the concrete industry because they affect placement and workability. Moreover, these rheological properties influence the productivity and quality of concrete, including mechanical properties and durability. Therefore proper characterization of these properties is needed to control the quality of fresh concrete and ensure sustainability of concrete structures. Fundamental and phenomenological rheological models have been proposed in the literature for characterizing the behaviour of fresh concrete. Establishing a model for predicting the Plastic Viscosity of concrete based on its composition will be extremely valuable for the concrete industry. This paper provides a critical review of the most prevailing models in concrete technology as well as models proposed in the literature for predicting the Plastic Viscosity of dense suspensions to a total of eight models. Review has revealed that Mahmoodzadeh and Chidiac models based on the cell method provides a higher degree of correlation to the experimental data as well as a more consistent and reliable predictions in comparison to the models currently proposed in the literature for concrete and/or dense suspensions. © 2009 Elsevier Ltd. All rights reserved.
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Controlling the quality of fresh concrete—a new approach
Magazine of Concrete Research, 2000Co-Authors: S E Chidiac, Omran Maadani, A. G. Razaqpur, N. P. MailvaganamAbstract:Traditionally, the slump test has been used to measure concrete consistency. However, many researchers contend that the slump alone is not a sufficient measure of consistency and that other quantifiable rheological properties such as shear yield stress and Plastic Viscosity are more representative and should be considered. A SLump Rate Machine (SLRM) was adapted and calibrated, to consistently measure the Plastic properties for a number of concrete mixes, namely slump rate and slump flow. Furthermore, a theoretical model was developed to correlate the slump flow and slump rate with the shear yield stress and Plastic Viscosity of fresh concrete, respectively. Employing the SLRM and the theoretical model has resulted in an efficient new approach to adequately predict the rheological behaviour of fresh concrete as well as to provide reasonably accurate values for shear yield stress and Plastic Viscosity.
F Mahmoodzadeh - One of the best experts on this subject based on the ideXlab platform.
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rheological models for predicting Plastic Viscosity and yield stress of fresh concrete
Cement and Concrete Research, 2013Co-Authors: F Mahmoodzadeh, S E ChidiacAbstract:Abstract Merits of the rheological models that have been proposed in the literature for characterizing the flow behavior of fresh concrete and concentrated suspensions are briefly assessed. New rheological models which employ the cell method are proposed for predicting the Plastic Viscosity and yield stress of fresh concrete on the basis of the mixture composition. Cell method, a geometric description, is mathematically proven to be representative of fresh concrete. Model predictions are evaluated using two experimental programs that use different testing apparatus, material properties and mixture composition. Statistical evaluation of the models reveals that their predictions are a good fit, display the same trend as the experimental data, are unbiased, yield good estimate, and do not systematically deviate from the measured values.
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Plastic Viscosity of fresh concrete – A critical review of predictions methods
Cement & Concrete Composites, 2009Co-Authors: S E Chidiac, F MahmoodzadehAbstract:Abstract Rheological properties of fresh concrete, namely Plastic Viscosity and yield stress, are critical for the concrete industry because they affect placement and workability. Moreover, these rheological properties influence the productivity and quality of concrete, including mechanical properties and durability. Therefore proper characterization of these properties is needed to control the quality of fresh concrete and ensure sustainability of concrete structures. Fundamental and phenomenological rheological models have been proposed in the literature for characterizing the behaviour of fresh concrete. Establishing a model for predicting the Plastic Viscosity of concrete based on its composition will be extremely valuable for the concrete industry. This paper provides a critical review of the most prevailing models in concrete technology as well as models proposed in the literature for predicting the Plastic Viscosity of dense suspensions to a total of eight models. Review has revealed that Mahmoodzadeh and Chidiac models based on the cell method provides a higher degree of correlation to the experimental data as well as a more consistent and reliable predictions in comparison to the models currently proposed in the literature for concrete and/or dense suspensions.
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Plastic Viscosity of fresh concrete a critical review of predictions methods
Cement & Concrete Composites, 2009Co-Authors: S E Chidiac, F MahmoodzadehAbstract:Abstract Rheological properties of fresh concrete, namely Plastic Viscosity and yield stress, are critical for the concrete industry because they affect placement and workability. Moreover, these rheological properties influence the productivity and quality of concrete, including mechanical properties and durability. Therefore proper characterization of these properties is needed to control the quality of fresh concrete and ensure sustainability of concrete structures. Fundamental and phenomenological rheological models have been proposed in the literature for characterizing the behaviour of fresh concrete. Establishing a model for predicting the Plastic Viscosity of concrete based on its composition will be extremely valuable for the concrete industry. This paper provides a critical review of the most prevailing models in concrete technology as well as models proposed in the literature for predicting the Plastic Viscosity of dense suspensions to a total of eight models. Review has revealed that Mahmoodzadeh and Chidiac models based on the cell method provides a higher degree of correlation to the experimental data as well as a more consistent and reliable predictions in comparison to the models currently proposed in the literature for concrete and/or dense suspensions.
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Plastic Viscosity of fresh concrete - A critical review of predictions methods
Cement and Concrete Composites, 2009Co-Authors: S E Chidiac, F MahmoodzadehAbstract:Rheological properties of fresh concrete, namely Plastic Viscosity and yield stress, are critical for the concrete industry because they affect placement and workability. Moreover, these rheological properties influence the productivity and quality of concrete, including mechanical properties and durability. Therefore proper characterization of these properties is needed to control the quality of fresh concrete and ensure sustainability of concrete structures. Fundamental and phenomenological rheological models have been proposed in the literature for characterizing the behaviour of fresh concrete. Establishing a model for predicting the Plastic Viscosity of concrete based on its composition will be extremely valuable for the concrete industry. This paper provides a critical review of the most prevailing models in concrete technology as well as models proposed in the literature for predicting the Plastic Viscosity of dense suspensions to a total of eight models. Review has revealed that Mahmoodzadeh and Chidiac models based on the cell method provides a higher degree of correlation to the experimental data as well as a more consistent and reliable predictions in comparison to the models currently proposed in the literature for concrete and/or dense suspensions. © 2009 Elsevier Ltd. All rights reserved.