Journal article
Measuring interparticle forces: Evaluation of superplasticizers for microsilica via colloidal probe technique



Publication Details
Authors:
Glotzbach, C.; Stephan, D.; Schmidt, M.
Publication year:
2013
Journal:
Cement and Concrete Composites
Pages range:
42-47
Volume number:
36
ISSN:
0958-9465

Abstract
Recent concretes like ultra-high performance concrete (UHPC) are comprised of large quantities of fines following a well-defined gradation to fill the voids between coarser particles, such as cement grains. The filling of voids displaces water, which positively influences the flowability. As the rheological properties of these fresh concretes depend mainly on the forces acting between the fines due to their high specific surface areas, understanding of these forces has become crucial. In this study, the atomic force microscopy technique of colloidal probes has been used to study the adhesive forces acting between individual silica particles placed in superplasticizer and electrolyte solutions, as silica exhibit the largest fraction of inner surface in common UHPC mixtures. Pairs of individual amorphous glass particles were approached and retracted from each other. Using this technique and silica particles as a model system, several commercial superplasticizers could be evaluated regarding their influence on the interparticle adhesion.


Keywords
Adhesion, Aggregation, Atomic force microscopy, Rheology, Silica fume, Surfactant

Last updated on 2019-25-07 at 14:28