纳米SiO_(2)、纳米TiO_(2)和纳米CaCO_(3)对水泥基材料早期性能的影响

Effects of nano-SiO_(2),nano-TiO_(2) and nano-CaCO_(3) on early properties of cement concrete

采用纳米SiO_(2)、纳米TiO_(2)和纳米CaCO_(3)分别替代部分水泥,研究了3种不同类型的纳米颗粒对水泥基材料流变性能、早期水化过程、早期强度和微观特性的影响。通过压汞孔隙度测定法(MIP)、热重分析仪(TG)、X射线衍射法(XRD)和扫描电子显微镜(SEM)观察纳米材料对水泥基材料早期微观结构及形貌的影响。探讨了3种纳米颗粒在改善水泥混凝土材料早期强度方面的差异。结果表明,纳米材料的填充效应、火山灰活性、成核效应,纳米尺寸效应及分散性等对水泥混凝土材料的早期力学性能有显著影响。

Nano-SiO_(2),nano-TiO_(2),and nano-CaCO_(3) were used to replace part of cement and the effects of different dosages and types of nano-particles on rheological properties,the early hydration process,early strength,and microscopic properties of cement-based materials were investigated.The microstructure morphology was observed by the mercury intrusion porosimetry(MIP),thermos gravimetric and differential thermal analysis(TG/DTG),and X-ray diffraction(XRD),and scanning electron microscope(SEM)were used to illuminate the formation of hydration and changes of the microstructure and morphology in cement paste at early age.The differences of the three nanoparticles in improving the early strength of cement concrete materials were discussed.The results showed that nanomaterials significantly influence the early-age mechanical properties because of their filler effects,pozzolanic activity,nucleation effects,nano-size effect and dispersion.