Effect of curing environment on length changes of alkali-activated slag/cement kiln by-pass dust mixtures

Abstract

This paper investigates the combination of commonly used blast furnace slag (BFS) and quite non-traditional cement kiln by-pass dust (BD) for the preparation of alkali-activated binder. More specifically, the possibilities of alkali-activated slag (AAS) shrinkage compensation and cracking mitigation using BD were studied. For this purpose, mixtures with ratios of BFS/BD ranging from 100/0 to 60/40 were prepared and cured in different environment, namely autogenous conditions, water curing, air curing and their combinations. The results showed that curing regime is a determinative parameter for performance of the mixtures: BD containing specimens showed a certain expansion during the first days of water curing leading to AAS shrinkage compensation, while in absence of water curing increasing dose of BD increased drying shrinkage significantly.This paper investigates the combination of commonly used blast furnace slag (BFS) and quite non-traditional cement kiln by-pass dust (BD) for the preparation of alkali-activated binder. More specifically, the possibilities of alkali-activated slag (AAS) shrinkage compensation and cracking mitigation using BD were studied. For this purpose, mixtures with ratios of BFS/BD ranging from 100/0 to 60/40 were prepared and cured in different environment, namely autogenous conditions, water curing, air curing and their combinations. The results showed that curing regime is a determinative parameter for performance of the mixtures: BD containing specimens showed a certain expansion during the first days of water curing leading to AAS shrinkage compensation, while in absence of water curing increasing dose of BD increased drying shrinkage significantly.