Effect of activator nature on property development of alkali-activated slag binders

Abstract

Alkali-activated material (AAS) is a potentially sustainable alternative binding material for Portland cement. This study focuses on the development of AAS properties and their interrelationships. The nature of the activating media, including sodium oxide content (Na₂O%) and silica modulus (Ms), is the main aspect of this work. The effects of Na₂O% and Ms on hydration evolution, setting time, compressive strength, autogenous, and drying shrinkage of AAS mortars have been evaluated. Results showed that the effects of Na₂O% and Ms differ from one property to another. Setting time and compressive strength were highly influenced by varying Na₂O% value, while Ms value had dominated the heat evolution and drying shrinkage of AAS. Moreover, the effects of activator nature on hydration product formation rate around slag particles substantially controlled properties development. Hence, the optimum values for Na₂O% and Ms need to be adapted based on the targeted performance.

Keywords:

• Heat of hydration
• autogenous shrinkage
• drying shrinkage
• compressive strength
• alkali-activated slag

Disclosure statement

No potential conflict of interest was reported by the authors.