Repulsion forces of superplasticizers on ground granulated blast furnace slag in alkaline media, from AFM measurements to rheological properties

[EN]The electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these su...

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Detalles Bibliográficos
Autores: Palacios, Marta, Kappl, M., Stuer, M., Aschauer, U., Bowen, Paul, Butt, H.J., Pecharromán, Carlos, Puertas, Francisca
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/73107
Acceso en línea:http://hdl.handle.net/10261/73107
Access Level:acceso abierto
Palabra clave:Dispersion
Ground granulated blast furnace slag
Surfaces
Suspensions
Rheology
Dispersión
Escoria granulada de horno alto
Superficies
Suspensiones
Reología
Descripción
Sumario:[EN]The electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these superplasticizers the slag suspensions had negative zeta potentials, ranging from -3 to -10 mV. For the first time the adsorbed layer thicknesses for superplasticizers on slag using colloidal probe atomic force microscopy has been measured. To model the interparticle force interactions an effective Hamaker constant was computed from dielectric properties measured on a dense slag sample produced by spark plasma sintering. The obtained results conclude that the dispersion mechanism for all the superplasticizers studied in the present work is mainly dominated by the steric repulsion. Results were then used in a yield stress model, YODEL, to predict the yield stress with and without the superplasticizers. Predictions of the yield stress agreed well with experimental results.