中文摘要：

研究了不同水灰比条件下聚丙烯纤维增强水泥基复合材料界面过渡区（ITZ）的纳米力学性能。通过纳米压痕试验测试界面过渡区及其附近区域的载荷一深度（P勘）曲线，运用Oliver-Pharr方法得到各测点弹性模量和压痕硬度，采用高倍显微镜成像与扫描电子显微镜技术绘制了界面过渡区微结构表征云图。利用反褶积法对水泥基体及界面过渡区的弹性模量及压痕硬度进行多峰拟合，得到了各相的频率分布。结果表明：不同水灰比条件下界面过渡区的厚度均处于10-20μm之间，且其弹性模量和压痕硬度均低于水泥基体的；随着水灰比的变化，界面过渡区水化产物的成分及体积分数也产生相应改变。

英文摘要：

The nanoscale mechanical properties of interfacial transition zone （ITZ） in polypropylene fiber reinforced cementitious composite for different water/cement ratios were investigated. The load-depth（P-h） curves of ITZ were determined via nanoindentation test. The corresponding elastic modulus and hardness were calculated by the Oliver-Pharr method. The microstructure nephograms were obtained by high-resolution microscopy and scanning electron microscopy. Furthermore, the frequency distribution of different phases in ITZ and cement was determined by a multi-peak fitting deconvolution method. The results indicate that the ITZs width ranged from 10 μm to 20 μm appears in all the cases. The hydration products vary at various water cement ratios.