Cui Dong, Wei Hao, Zuo Xiaobao, Zheng Keren, Wang Qiannan
Department of Civil Engineering, School of Science, Nanjing University of Science & Technology, Nanjing 210094, China.
Department of Civil Engineering, Central South University, Changsha 410075, China.
Nanomaterials (Basel). 2020 Nov 29;10(12):2385. doi: 10.3390/nano10122385.
Nanomaterials have received increased concentration in the field of civil engineering, as their incorporation can effectively modify the mechanical and transport properties of cementitious composites. In this study, to understand the effect of graphene oxide (GO) nanoparticles on the durability and mechanical properties of cementitious composites serving underwater, mortars incorporated with GO were taken for study. To match the real circumstance, all specimens were immersed directly in a flowing river for three years, and their transport properties, mechanical properties and microstructure before, and after, river experience were studied separately. The results showed that the incorporation of GO could reduce both early-age permeation coefficient and later-age chloride migration coefficient of mortar specimens. The average porosities of mortars could be reduced by the range of 3.37-11% with GO incorporation. Moreover, through a novel dual-scan method, GO incorporation was confirmed effective in enhancing both the leaching and cracking resistance. Furthermore, the compressive strengths, flexural strengths and splitting tensile strengths could be improved by the range of 4.37-9.82%, 7.78-22.33%, 8.14-28.73%, respectively with GO incorporation, and the tested mechanical strengths for GO-incorporated mortar after three-year river experience could be retained to a higher extent. Finally, based on durability and mechanical properties, the optimum mix proportion of GO was determined to be 0.06 wt.% in this study. The work presented here is of high reference value for the designing of marine infrastructure and can help promote the application of nanomaterials in civil engineering.
纳米材料在土木工程领域受到了越来越多的关注，因为它们的加入可以有效地改善水泥基复合材料的力学性能和传输性能。在本研究中，为了解氧化石墨烯（GO）纳米颗粒对水下服役水泥基复合材料耐久性和力学性能的影响，对掺入GO的砂浆进行了研究。为了匹配实际情况，将所有试件直接浸入流动的河流中三年，并分别研究了它们在河流浸泡前后的传输性能、力学性能和微观结构。结果表明，掺入GO可以降低砂浆试件的早期渗透系数和后期氯离子迁移系数。掺入GO后，砂浆的平均孔隙率可降低3.37%-11%。此外，通过一种新颖的双扫描方法，证实掺入GO对提高抗浸出性和抗裂性均有效。此外，掺入GO后，抗压强度、抗折强度和劈裂抗拉强度分别可提高4.37%-9.82%、7.78%-22.33%、8.14%-28.73%，且经过三年河流浸泡后，掺入GO的砂浆的测试力学强度能在更大程度上得以保留。最后，基于耐久性和力学性能，本研究确定GO的最佳掺量为0.06 wt.%。本文的工作对海洋基础设施的设计具有很高的参考价值，并有助于推动纳米材料在土木工程中的应用。
