Research On Nano-ZrO₂ Powders Prepared By Super-Alkaline Synthetic Method At Low Temperature And The Effects Of Them On Modified Cement

The development of composite-cement and nanometer-materials at home and abroad is briefly introduced in this thesis, and physical properties of OPC are summarized. On basis of completely summing up the preparation methods and applications of nano-zirconia powder and aiming at the practical conditions, a feasible method, namely super-alkaline method at low temperature is chosen, which is a convenient operation without environmental pollution .Then, nano-ZrO2 powders by calcined at different temperatures are added into cement and, compound effect of the composite-cement are also discussed. In addition to compressive strength testing, the relation among components, microstructure and performance is evaluated by XRD,TEM and DTA testing.The properties of nano-ZrO2 powder prepared by super-alkaline methodat low temperature are different from those of ordinary ZrO2 powder, and the phase-change temperature is lower. The nano-ZrO2 powder has quasi-phase transformation rules.Nano-ZrO2 powders by calcined at different temperatures is added into cement in different amounts and hydration tests are carried on. The results show that the nano-ZrO2 powder by calcined at 1200癈 is a kind of more prefect intensifier, and the compressive strength of 3d and 28d rises mostly. And the tests of XRD, TEM and DTA indicate that the nano-ZrOa powder has nano-meter inducement hydration effect.The obvious relation between compressive strength and porosity existed in the composite-cement. Commonly, the less porosity of hydrates is, the higher compressive strength is. So the anti- permeability is better.In this paper, quasi-phase change rules and nano-meter inducement hydration effect are put forward. And the studies indicate that the cement mixed with nano-ZrO2 has higher compressive strength and better anti-permeability, so the materials take on excellent properties and advanced exploitation potential.