Al Qader Huda, Jasim Ahmed M, Salim Hani, Xing Yangchuan, Stalla David
Department of Environmental and Civil Engineering, University of Missouri, Columbia, MO 65211, USA.
Department of Biomedical, Biological, and Chemical Engineering, University of Missouri, Columbia, MO 65211, USA.
Materials (Basel). 2022 Apr 9;15(8):2768. doi: 10.3390/ma15082768.
This study evaluated the effect of carbon nanofibers (CNFs) coated by aluminum oxide AlO as a reinforcement on compressive strength, frost resistance, and drying shrinkage of cement mortars. Three weight ratios of 0.125%, 0.25%, and 0.5% of AlO/CNFs and bare CNF cement mortars were compared with reference cement mortar samples. The reactive porous and high surface area layer of alumina induced the hydration reaction and promoted the production of well-distributed hydration gel. Derivative thermal analysis-differential thermogravimetric (TGA-DTG) and X-ray powder diffraction (XRD) characterization showed that AlO/CNFs reinforcement led to greater hydration gel production than bare CNFs. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to study the coating and microstructure of the cement mortars evaluated in this paper. The results show that the optimum enhancement of the cement mortar properties was obtained at ratios of 0.125% for AlO/CNFs and 0.25% for CNFs. This enhancement was greater with AlO/CNFs-reinforced specimens in terms of high compressive strength, less compressive strength degradation after 150 cycles, and less drying shrinkage. The low use of the CNFs in AlO/CNFs samples indicates the coating is an economical and promising approach for improving the performance of cement mortars.
本研究评估了用氧化铝（AlO）包覆的碳纳米纤维（CNFs）作为增强材料对水泥砂浆抗压强度、抗冻性和干燥收缩的影响。将AlO/CNFs的三种重量比0.125%、0.25%和0.5%的水泥砂浆以及裸露的CNF水泥砂浆与参考水泥砂浆样品进行了比较。氧化铝的活性多孔且高表面积层引发了水化反应，并促进了分布均匀的水化凝胶的生成。导数热分析-差示热重分析（TGA-DTG）和X射线粉末衍射（XRD）表征表明，AlO/CNFs增强材料比裸露的CNFs产生了更多的水化凝胶。进行了透射电子显微镜（TEM）和扫描电子显微镜（SEM）分析，以研究本文评估的水泥砂浆的包覆情况和微观结构。结果表明，AlO/CNFs重量比为0.125%、CNFs重量比为0.25%时，水泥砂浆性能得到最佳增强。在高抗压强度、150次循环后抗压强度降解较小以及干燥收缩较小方面，AlO/CNFs增强的试件增强效果更显著。AlO/CNFs样品中CNFs用量较低，表明这种包覆是一种经济且有前景的改善水泥砂浆性能的方法。
