Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Combination of superplasticizers with hydroxypropyl guar, effect on cement-paste properties
https://orcid.org/0000-0002-0528-4079
Highlights A specific method is proposed for adsorption quantification of PCE combined with HPG. The adsorption of the HPG is decreased by the presence of PCE. The adsorption of only the lowest charged PCE is affected by the HPG. The change in adsorption modifies the yield stress and the viscosity of the pastes.
Abstract Viscosity-modifying agent (VMA) are used in several applications of concrete, such as underwater concrete, Self-Compacting Concrete (SCC) or Self-Levelling Underlayments (SLU) in order to improve the washout resistance and the stability. The study focuses on the modifications of cement pastes properties implied when a VMA (hydroxypropyl guars or HPG) and a superplasticizer are introduced together. For reaching this objective, two chemically different polycarboxylate-based superplasticizers (PCE) and two HPGs exhibiting different molar substitution ratios (MSHP), were studied. A method, combining total organic carbon and size exclusion chromatography, was developed in order to quantify the adsorption of the both admixtures. The adsorption of HPGs appears being significantly lowered by the presence of PCE, while only the adsorption of the less charged PCE is slightly affected by the HPG. As consequence, strong modifications of the rheological properties of cement pastes were noticed when HPG and PCE are combined. The desorption of HPG leads to higher yield stress and residual viscosity than with PCE alone.
Combination of superplasticizers with hydroxypropyl guar, effect on cement-paste properties
https://orcid.org/0000-0002-0528-4079
Highlights A specific method is proposed for adsorption quantification of PCE combined with HPG. The adsorption of the HPG is decreased by the presence of PCE. The adsorption of only the lowest charged PCE is affected by the HPG. The change in adsorption modifies the yield stress and the viscosity of the pastes.
Abstract Viscosity-modifying agent (VMA) are used in several applications of concrete, such as underwater concrete, Self-Compacting Concrete (SCC) or Self-Levelling Underlayments (SLU) in order to improve the washout resistance and the stability. The study focuses on the modifications of cement pastes properties implied when a VMA (hydroxypropyl guars or HPG) and a superplasticizer are introduced together. For reaching this objective, two chemically different polycarboxylate-based superplasticizers (PCE) and two HPGs exhibiting different molar substitution ratios (MSHP), were studied. A method, combining total organic carbon and size exclusion chromatography, was developed in order to quantify the adsorption of the both admixtures. The adsorption of HPGs appears being significantly lowered by the presence of PCE, while only the adsorption of the less charged PCE is slightly affected by the HPG. As consequence, strong modifications of the rheological properties of cement pastes were noticed when HPG and PCE are combined. The desorption of HPG leads to higher yield stress and residual viscosity than with PCE alone.
Combination of superplasticizers with hydroxypropyl guar, effect on cement-paste properties
https://orcid.org/0000-0002-0528-4079
Highlights A specific method is proposed for adsorption quantification of PCE combined with HPG. The adsorption of the HPG is decreased by the presence of PCE. The adsorption of only the lowest charged PCE is affected by the HPG. The change in adsorption modifies the yield stress and the viscosity of the pastes.
Abstract Viscosity-modifying agent (VMA) are used in several applications of concrete, such as underwater concrete, Self-Compacting Concrete (SCC) or Self-Levelling Underlayments (SLU) in order to improve the washout resistance and the stability. The study focuses on the modifications of cement pastes properties implied when a VMA (hydroxypropyl guars or HPG) and a superplasticizer are introduced together. For reaching this objective, two chemically different polycarboxylate-based superplasticizers (PCE) and two HPGs exhibiting different molar substitution ratios (MSHP), were studied. A method, combining total organic carbon and size exclusion chromatography, was developed in order to quantify the adsorption of the both admixtures. The adsorption of HPGs appears being significantly lowered by the presence of PCE, while only the adsorption of the less charged PCE is slightly affected by the HPG. As consequence, strong modifications of the rheological properties of cement pastes were noticed when HPG and PCE are combined. The desorption of HPG leads to higher yield stress and residual viscosity than with PCE alone.
Combination of superplasticizers with hydroxypropyl guar, effect on cement-paste properties
Govin, Alexandre (Autor:in) / Bartholin, Marie-Claude (Autor:in) / Schmidt, Wolfram (Autor:in) / Grosseau, Philippe (Autor:in)
Construction and Building Materials ; 215 ; 595-604
16.04.2019
10 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Admixture , Rheology , Adsorption , Polymers , Pore solution
Effect of Various Superplasticizers on Rheological Properties of Cement Paste and Mortars
| British Library Online Contents | 1994
Effect of Various Superplasticizers on Rheological Properties of Cement Paste and Mortars
| Online Contents | 1994
Effect of retarding superplasticizers on the properties of cement paste, mortar and concrete
| Online Contents | 2019
Effect of retarding superplasticizers on the properties of cement paste, mortar and concrete
| Springer Verlag | 2019