Effect of cement kiln dust and lignosulfonate on cement paste: a rheology and hydration kinetics study

Abstract

This research provides a comprehensive analysis of the influence of cement kiln dust (CKD) and lignosulfonate (LS) on the rheology and hydration kinetics of cement paste. The interaction effect, dispersion potential, and adsorption kinetics of LS on the cement/CKD paste were obtained using UV spectroscopy and zeta potential measurements. The results indicate that the addition of LS reduces the yield stress and plastic viscosity through the dispersion effect of LS, which alters the adhesion of the particles and improves the rheology of the CKD/cement paste. The competing adsorption of LS by the cement and CKD particles increased the flowability of the cement paste and a maximum was obtained due to the stable combined action of two different mechanisms of steric hindrance and electrostatic repulsion by LS. The X-ray Diffraction analysis performed to evaluate the hydration response of cement with LS and CKD showed greater conversion potentials of SiO2 to stable CSH.