【摘要】 对掺纳米SiO2和掺硅粉高强混凝土性能进行了研究,同时应用XRD和SEM对纳米SiO2、硅粉与水泥硬化浆体/大理石界面中氢氧化钙的反应程度进行了探讨.结果表明,掺入1%～3%纳米SiO2能显著提高混凝土的抗折强度、提高混凝土早期抗压强度和劈裂抗拉强度.掺3%纳米SiO2的混凝土,与掺10%硅粉的混凝土相比,其抗折强度约提高4%～6%,而与不掺硅粉的混凝土相比,其抗折强度约提高31%～57%.在3%相同掺量的条件下,与硅粉比较,纳米SiO2能更有效地吸收水泥硬化浆体/大理石界面中所富集的氢氧化钙,更有效地细化界面中的氢氧化钙晶粒,从而起到改善界面的积极作用.更多还原

【Abstract】 The comparison of properties of high strength concrete(HSC) with nanoSiO2 (NS) or silica fume(SF) added was made according to Chinese standard for cement and concrete and by the means of XRD and SEM. Results indicate that the flexural strength, compressive strength and tensile splitting strength of HSC with NS added are higher than those of HSC with SF, and their developments are normal. It is obvious that the flexural strength of HSC added with 3%NS is increased by 31%～57% compared with that of HSC without NS and SF, and by 4%～6% compared with that of HSC with 10%SF added. Portlandite in interface between marble and HCP added with 3%NS is digested obviously and its crystal size is reduced more than those with 10%SF added. In summary the properties of HSC with nanoSiO2 added are better than that of HSC with silica fume added.更多还原