A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Effect of viscosity-modifying admixture-superplasticizer combination on flow properties of SCC equivalent mortar
The understanding of the effect of specialty admixtures on the rheological properties of self-consolidating concrete (SCC) is of special interest for the design of high-performance SCC. This paper reviews the classifications and modes of action of viscosity-modifying admixture (VMA) and investigates the influence of the type and concentration of VMA and high-range water reducing admixture (HRWRA) and on flow properties of concrete equivalent mortars (CEMs) deducted from high-performance SCC mixtures. This includes the influence of admixture combinations on shear stress-shear rate behavior, pseudoplasticity, shear recovery, and thixotropy. Test results show that CEM can exhibit Bingham flow behavior, except in the case of highly flowable mixtures where a Hershell-Bulckely or power flow model can be describe the flow of the CEM. The effectiveness of VMA in use to enhance viscosity and thixotropy depends on the HRWRA in use. The degree of pseudoplasticity is mostly affected by the combination of HRWRA and VMA. Mixtures made with a copolymer HRWR were found to be more viscous than mixtures proportioned with PNS, PMS, or polycarboxylate-based HRWRA. Mixtures with polycarboxylate-based HRWRA exhibited greater pseudoplasticity than those with PNS, PMS, or copolymer HRWRA.
Effect of viscosity-modifying admixture-superplasticizer combination on flow properties of SCC equivalent mortar
The understanding of the effect of specialty admixtures on the rheological properties of self-consolidating concrete (SCC) is of special interest for the design of high-performance SCC. This paper reviews the classifications and modes of action of viscosity-modifying admixture (VMA) and investigates the influence of the type and concentration of VMA and high-range water reducing admixture (HRWRA) and on flow properties of concrete equivalent mortars (CEMs) deducted from high-performance SCC mixtures. This includes the influence of admixture combinations on shear stress-shear rate behavior, pseudoplasticity, shear recovery, and thixotropy. Test results show that CEM can exhibit Bingham flow behavior, except in the case of highly flowable mixtures where a Hershell-Bulckely or power flow model can be describe the flow of the CEM. The effectiveness of VMA in use to enhance viscosity and thixotropy depends on the HRWRA in use. The degree of pseudoplasticity is mostly affected by the combination of HRWRA and VMA. Mixtures made with a copolymer HRWR were found to be more viscous than mixtures proportioned with PNS, PMS, or polycarboxylate-based HRWRA. Mixtures with polycarboxylate-based HRWRA exhibited greater pseudoplasticity than those with PNS, PMS, or copolymer HRWRA.
Effect of viscosity-modifying admixture-superplasticizer combination on flow properties of SCC equivalent mortar
Khayat, K. (author) / Ghezal, A. (author)
2003
17 Seiten, 12 Bilder, 4 Tabellen, 15 Quellen
Conference paper
English
| British Library Conference Proceedings | 2003
| European Patent Office | 2020
| British Library Conference Proceedings | 1994