A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Robustness of cement suspensions - superplasticizer adsorption, particle separation and interparticle forces
The robustness of cement suspensions is directly related to the volumetric water/powder ratio of the cement paste and the superplasticizer adsorption on particle surfaces. The robustness of mortar with respect to overdosage of water at similar initial flowability increases with water/powder ratio and decreases with superplasticizer dosage. High specified water contents in the mix combined with low superplasticizer dosages affect the robustness positively. A model based on inter-particle interactions between powder particles (< 100 microns) is presented which qualitatively explains the rheological behaviour of fresh concrete and enables the prediction of robustness for a given mix. The model considers the interactions between particles in direct contact and interactions between surrounding particles not in direct contact. This permits the control of yield stress, thixotropy, robustness and thus the required workability during mix design phase by the choice of suitable combinations of cement and additions. The model contributes towards understanding the properties of fresh concrete such as segregation and formwork pressure which are difficult to control under field conditions. This leads to better reliability in the production of, in particular, flowable high performance concretes such as SCC.
Robustness of cement suspensions - superplasticizer adsorption, particle separation and interparticle forces
The robustness of cement suspensions is directly related to the volumetric water/powder ratio of the cement paste and the superplasticizer adsorption on particle surfaces. The robustness of mortar with respect to overdosage of water at similar initial flowability increases with water/powder ratio and decreases with superplasticizer dosage. High specified water contents in the mix combined with low superplasticizer dosages affect the robustness positively. A model based on inter-particle interactions between powder particles (< 100 microns) is presented which qualitatively explains the rheological behaviour of fresh concrete and enables the prediction of robustness for a given mix. The model considers the interactions between particles in direct contact and interactions between surrounding particles not in direct contact. This permits the control of yield stress, thixotropy, robustness and thus the required workability during mix design phase by the choice of suitable combinations of cement and additions. The model contributes towards understanding the properties of fresh concrete such as segregation and formwork pressure which are difficult to control under field conditions. This leads to better reliability in the production of, in particular, flowable high performance concretes such as SCC.
Robustness of cement suspensions - superplasticizer adsorption, particle separation and interparticle forces
Stabilität von Zementsuspensionen - Adsorption von Superplastifizierern, Partikeltrennung und interpartikuläre Kräfte
Lowke, D. (author) / Schießl, P. (author)
2009
10 Seiten, 7 Bilder, 3 Tabellen, 13 Quellen
Conference paper
English
| British Library Conference Proceedings | 2009
Interparticle forces and superplasticizers in cement suspensions
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Cement and Superplasticizer Combinations: Compatibility and Robustness
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Cement and Superplasticizer Combinations: Compatibility and Robustness
| British Library Online Contents | 2004