Abstract
The effect of montmorillonite on the hydration reactions and fluidity of cement paste was investigated using comb-type superplasticizer or sodium gluconate. When comb-type superplasticizer was added, montmorillonite affected the retar-dation action of the initial hydration reaction in the cement and the dispersion significantly. When sodium gluconate was added, the effect of the montmorillonite on the retardation action was smaller compared with that of the comb-type su-perplasticizer. The amount of comb-type superplasticizer adsorbed on the cement particles is reduced significantly by the addition of montmorillonite. In the case of sodium gluconate, the amount adsorbed on the cement particles is also de-creased by the addition of montmorillonite. However the adsorbed amount of sodium gluconate on montmorillonite is smaller compared with that of superplasticizer on montmorillonite.
