2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
Comparative Analysis of Reaction Kinetics of One and Two Parts Geopolymers

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Author(s)
Ms. Wala'a Almakhadmeh, Concordia University (Presenter)
Dr. Ahmed Soliman, Concordia University
Abstract

W. Almakhadmeh1 and A.M. Soliman2

1. PhD student, Department of Building, Civil and Environmental Engineering,

 Concordia University, Montreal Quebec Canada

2. Assistant Professor, Department of Building, Civil and Environmental Engineering,

 Concordia University, Montreal Quebec Canada 

Alkali-activated materials (AAMs) are recognized as potential alternatives to ordinary Portland cement (OPC). AAMs have a low carbon dioxide emission as well as consume industrial byproducts instead of sending to landfilled. Concentrated aqueous alkali solutions is used to start the activation process of the solid aluminosilicate precursor and form the binding material in AAMs. Alkali activate slag is one of the promising AAMs, however, its high drying shrinkage strain is one of the main disadvantages. Effect of varying the silica modulus (Ms) with 4% concentration of alkaline activator Na2O% has been investigated. Fresh and hardened properties, including setting time, heat of hydration, compressive strength, and drying and autogenous shrinkage tests were evaluated for all tested mixtures. Results show that increasing Ms shortened the final setting time, and increased the 28 days’ compressive strength. Correspondingly, the autogenous and drying shrinkage also increase as Ms values increased. This highlighted the importance of controlling the Ms value to achieve adequate strength while maintaining lower shrinkage.

Key Words: Silica modulus, Cement, pastes, Alkali activated slag; Heat of hydration.