Influence of new laboratory prepared superplasticizers on the hydration and adsorption characters of cement pastes

New superplasticizers for cement and concrete were prepared in the laboratory; these materials are based on water-soluble melamine (formaldehyde-free) polycondensate products. The condensation firstly performed between the melamine and the glyoxalic acid in acid medium and, secondly the product condensed with monoethanolamine or diethanolamme. The chemical structures of the products are confirmed through different spectroscopic techniques. The effect of these polymers on the fluidity of the sulfate resisting cement pastes was investigated through the minislump test. Meanwhile the amount of adsorption of these polymers on cement particles during 30 min of hydration was determined by total organic carbon TOC, in the pastes solution. The influence of adsorption of these polymers on the hydration kinetics of the sulfate resisting cement SRC pastes was investigated through the determination of the chemically combined water content of dried pastes, Ca+2 Concentrations and conductivity of the samples solution. The results reflect that the new superplasticizers increase the fluidity and the ministump of cement pastes, due to the adsorption of these polymers on the cement particles, which results in an increase of cement particles repulsion and decreases the rate of hydration.