Effect of activator nature on property development of alkali-activated slag binders
W. Al Makhadmeh, Ahmed Soliman
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.