Influence of β-cyclodextrin modified PCE on fluidity and hydration behavior of cement paste

Abstract

A series of β-cyclodextrin (β-CD) modified polycarboxylate (PCE) was prepared. β-CD was first grafted onto polyethylene oxide chain to produce β-CD-HPEG, and β-CD-HPEG was then adopted to replace part of HPEG to fabricate β-CD modified PCE. The adsorption-dispersing performance of PCEs and cement hydration properties were investigated. Results showed that the insertion of β-CD into the side chain led to impaired adsorption behavior of PCE polymer onto cement particle, but performed higher steric hindrance effect. The dispersing behavior of β-CD modified PCE varied with the insertion ratio of β-CD modified HPEG. β-CD modified PCE exhibited enhanced retardation effect on cement hydration, resulting in prolonged induction period, decreased hydrates at early age. But, due to the enhanced dispersing performance of β-CD modified PCE, the hydration degree was promoted at 28d, resulting in more hydrates formed in the matrix and denser microstructure.