Effect Of Superplasticizer On The Performance And Early Hydration Of Less Clinker Cementitious Material

Cement production consuming power, mineral resource and produce CO_2- From the view of protect the environment and product the high performance concrete, the trend of cement & concrete is improve the performance, increase the amount of cement replacement by industrial waste and used less of clinker.In order to further explore the effect of superplasticizer on grinding clinker, two different kinds of superplasticizer, including naphthalene and polycarboxylate, were taken while grinding cement. The Blaine fineness and particle size distribution result shows that, added superplasticizer when cement clinker grinding, it decrease the Blaine fineness of cement while the amount of superplasticizer smaller than 0.03% but increase more than this amount of it. The result of particle size distribution show that the particle which small than 45μm have the most while the superplasticizer amount is 0.03%.The properties of grinding samples were measured by the viscosity, losing of water, compressive strength and flexural strength, Used the grinding samples and mineral admixture produced the less clinker cementitious material, at the same time, the conductivity and heat of hydration and the chemical shrinkage of samplers were measured to study the early hydration. The result show that, taking superplasticizer while grinding, decrease the compressive strength and flexural strength of mortar and the viscosity of flesh pastes, increase the losing of water. By measured the change of conductivity and the heat of hydration, the superplasticizer also decrease the change of conductivity and early heat evolution ratio from the beginning of cement hydration. While the replacement of mineral admixture up to 70%, the delay hydration effect of superplasticizer become no more distinctness. Mineral admixture and superplasticizer together can apparently decrease the chemical shrinkage. Only hydration of cement is fast, the superplasticizer can decrease the chemical shrinkage apparently while the same amount mineral admixture.