Liu Shuangshuang, Lu Fenglei, Chen Ya, Dong Biqin, Du Hongxiu, Li Xiangyu
College of Civil Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
Guangdong Province Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China.
Materials (Basel). 2022 Mar 16;15(6):2181. doi: 10.3390/ma15062181.
Graphene oxide (GO) has been found to be an attractive nanomaterial to improve the properties of cementitious composites. However, the use of GO in the industry is limited by its high cost. To achieve a higher cost/performance ratio, GO can be strategically applied in certain parts of cementitious composites structure according to the principle of functionally graded materials. In this study, graded distribution of GO in cement mortar was achieved by sequentially casting a fresh GO-incorporated cement layer on another cement mortar layer. The mechanical properties, especially flexural strength, of layered cement mortar were found to be dependent on the GO content, the delay time, and the interface formed due to layering fabrication. With the GO incorporated in the tensile region only (30% of the total depth), the flexural strength of the layered beam attained 90.91% of that of the beam, with GO uniformly distributed throughout the sample. Based on the results of rapid chloride migration tests, when 12 mm GO-incorporated cement mortar layer was used, the chloride migration coefficient was reduced by 21.45%. It was also found that the measured chloride migration coefficient of layered cement mortar agreed with the series model. The present investigation provides an efficient approach to use GO in cement-based materials from the perspective of mechanical and durability properties.
氧化石墨烯（GO）已被发现是一种有吸引力的纳米材料，可用于改善水泥基复合材料的性能。然而，GO在工业中的应用受到其高成本的限制。为了实现更高的性价比，根据功能梯度材料的原理，GO可以策略性地应用于水泥基复合材料结构的某些部位。在本研究中，通过在另一水泥砂浆层上依次浇筑新鲜的含GO水泥层，实现了GO在水泥砂浆中的梯度分布。发现层状水泥砂浆的力学性能，特别是抗弯强度，取决于GO含量、延迟时间以及分层制造形成的界面。当GO仅掺入拉伸区域（总深度的30%）时，层状梁的抗弯强度达到GO均匀分布在整个样品中的梁的抗弯强度的90.91%。基于快速氯离子迁移试验的结果，当使用12 mm厚的含GO水泥砂浆层时，氯离子迁移系数降低了21.45%。还发现层状水泥砂浆的实测氯离子迁移系数与串联模型相符。本研究从力学和耐久性性能的角度提供了一种在水泥基材料中使用GO的有效方法。
