In this work, a methodology is presented in order to assess the microstructure of Portland Cement through advanced characterisation. Nanoindentation is used to determine reduced elastic modulus and hardness, which are involved in the design of construction materials. Elemental mapping and X-ray scanning microtomography were also used to establish structure-property relations through porosity distribution and morphology as well as phase identification by nanoindentation and image analysis. The variation of carbon nanotubes (CNTs) concentration between 0.02 and 1.0 wt% demonstrated alterations in phase composition, and thus the effect of CNTs reinforcement in hydration progress was clarified. Characterisation by all techniques identified 0.5 wt% concentration as promising due to the formation of higher density hydrated phases, even though total porosity was not minimized. This fact was explained by nanoindentation as enhanced Calcium-Silicate-Hydrates connectivity in the porous network was detected. The voids of cement were filled with low stiffness hydrated gel phases as a result of enhanced hydration in the presence of CNTs.

在这项工作中，提出了一种方法，以通过高级表征评估波特兰水泥的微观结构。纳米压痕用于确定降低的弹性模量和硬度，这与建筑材料的设计有关。元素映射和X射线扫描显微照相术还用于通过孔隙率分布和形态以及通过纳米压痕和图像分析进行相鉴定来建立结构-性质关系。碳纳米管（CNT）浓度在0.02和1.0 wt％之间的变化表明相组成发生了变化，因此阐明了CNTs增强对水合作用的影响。所有技术的鉴定都表明，由于形成了更高密度的水合相，因此0.5 wt％的浓度很有希望，即使总孔隙率没有最小化。纳米压痕解释了这一事实，因为在多孔网络中检测到钙硅酸盐水合物的连接性增强。由于在CNT的存在下增强了水合作用，所以水泥的空隙被低刚度的水合凝胶相填充。