纳米TiO_2对水泥基材料的增韧效果及作用机制  

The influence and mechanism of nano-TiO_2 on the toughness of cement-based materials

作　　者：马保国[1] 李海南[1] 梅军鹏[1] 韩磊[1] 陈方颉 

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《功能材料》2015年第12期12065-12069,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51378408);中央高校基本科研业务费专项资金资助项目(2013-YB-25)

摘　　要：通过力学强度、SEM、XRD和MIP测试手段,研究了NT对水泥砂浆机械性能与微观结构的影响。结果表明,3%NT可显著提高水泥砂浆的抗拉和抗折强度,28 d时相比空白样分别提高了68.2%和63.2%;促进AFt的结晶析出,其含量较空白样提高了62.6%,并与水泥砂浆的抗拉和抗折强度呈现明显的正向关系;使28 d时硬化浆体内部孔隙率降低了37.0%,无害孔增加了41.0%,有害孔降低了37.9%,即孔结构明显细化并向无害孔转移。研究结果说明了3%NT可明显改善水泥砂浆韧性与密实度,并提出了NT对水泥水化晶体的形成具有模板成核作用和调控晶体生长效应。The influences of nano-Ti O2(NT) on microstructures and mechanical properties of cement mortars were studied by strength test,scanning electron microscope( SEM),X-ray diffraction( XRD) and mercury intrusion porosimetry(MIP). Results show that,3% NT can significantly improve the tensile and flexural strengths,which increase by 68.2% and 63. 2% at 28 days respectively compared those without NT. And it also promotes the precipitation of AFt crystals,which increase by 62. 6%. The tensile and flexural strengths have significant positive correlation to the formation amount of AFt. The internal porosity,and harmful pore of hardened mortars at 28 d decrease by 37. 0% and 37. 9% respectively,while the harmless pores increase by 41. 0%,namely pores of mortars are significantly refined and shift to harmless pores. The result of research indicates that 3% NT can effectively improve the toughness and compactness of mortars,and the template nucleation effect and crystal growth regulation effects of NT on the formation of hydration products are presented.

关 键 词：砂浆 纳米TIO2 抗拉强度 抗折强度 韧性 

分 类 号：TU528.0[建筑科学—建筑技术科学]