Title: Effect of Solution Chemistry on Superplasticizers in Alkali-Activated Slag

Author(s): C. Paillard, N. Sanson, J.-B. d’Espinose de Lacaillerie, G. Ducouret, P. Boustingorry, M. Jachiet, C. Giraudeau and V. Kocaba

Publication: Symposium Paper

Volume: 354

Issue:

Appears on pages(s): 157-164

Keywords: alkali activator, slag, polycarboxylates ethers

DOI: 10.14359/51736069

Date: 7/1/2022

Abstract:
The hardening of alkali-activated slags is a complicated process that leads to the formation of cementitious materials with a lower carbon footprint than ordinary Portland cement. These materials present varying rheological, mechanical, and chemical properties, depending on the used activators and the preparation method. With a rapid stiffening often observed, the last major hindrance to their industrialization at a large scale is the control of their workability. However, the use of traditional superplasticizers as polycarboxylates ethers has had only limited effects. To shed some light on the interactions between the three components, samples of slag activated with sodium hydroxide and admixed with polycarboxylate ethers are analyzed by isothermal calorimetry, rheology, adsorption measurements, and pore solution chemical analysis. Depending on the polymer structure, we discuss a possible coupling between the adsorption and conformation of the polymer at the slag surface on the one hand, and solution chemistry on the other hand.