纳米级SiO_2改性水泥胶砂作用机理研究

Research on Reaction Mechanism of Cement-Motar by Nano-SiO_2

用XRD、TGA-DTA分析了纳米级SiO2改性水泥砂浆后的水泥基材料的性能变化,探索了纳米级SiO2的改性机理。XRD、TGA-DTA分析表明水泥砂浆被改性后,Ca(OH)2晶体取向程度降低,晶粒细化且呈无定型。改性后水化产物增多,导致强度增大。除了进行微观力学性能测试之外,用SEM测试评价了纳米级SiO2改性水泥砂浆后的微观形貌,发现在水泥基中添加纳米级SiO2能使水化速率增快,水化产物增多,龄期结构变得致密,导致强度增大,耐久性提高。

The characteristics of nano-SiO2 powder investigated with XRD and TGA-DTA for cementing composite materials were discussed and the mechanism were quested. The result of XRD and TGA-DTA test show that, cementing composite materials were modified, and Ca（ OH）2 crystal degree of orientation decreases , crystal grain subdivides and shows itself amorphism . After modified, the hydration products increase and results to the increasing of the strength. The microstructure of the modified cementing composite materials was evaluated with SEM testing besides the testing of micro mechanics property. The result shows, after adding nano-SiO2 to cementing composite materials the hydration speed accelerates, the hydration products increase, the stadium structure gets tight, and the intensity strengthened.