For the improvement of mechanical and microstructural properties of UHPC with fiber alignment using carbon nanotube and graphite nanoplatelet. (May 2022)

• Record Type: Journal Article
• Authors: Huang, Huanghuang; Teng, Le; Khayat, Kamal H.; Gao, Xiaojian; Wang, Fazhou; Liu, Zhichao
• Is Part Of: Cement & concrete composites. Volume 129(2022)
• Publication Date: 2022-05
• Subjects: Carbon nanotube -- Fiber alignment -- Graphite nanoplatelet -- Microstructure and mechanical properties -- UHPC; Composite-reinforced concrete -- Periodicals; Concrete -- Periodicals; Composite materials -- Periodicals; Composites de ciment -- Périodiques; Béton -- Périodiques; Composites -- Périodiques; Béton léger -- Périodiques; Cement composites; Composite materials; Composite-reinforced concrete; Concrete; Lightweight concrete; Periodicals; Electronic journals; 620.135
• DOI: 10.1016/j.cemconcomp.2022.104462
• Languages: English
• ISSNs: 0958-9465

Abstract

Abstract: This paper investigates the influence of carbon nanotube (CNT) and graphite nanoplatelet (GNP) on the microstructure and mechanical characteristics of UHPC with steel fiber alignment. The content of CNT and GNP ranged from 0 to 0.3%, by mass of binder. Predominant fiber alignment was manipulated using a flow-induced casting method during UHPC placement. Experiment results indicated that the increase of CNT and GNP content from 0 to 0.3% led to 15%, 40%, and 50% improvement in compressive strength, flexural strength, and T150 (dissipated energy) of UHPC, respectively. Fiber alignment was shown to increase flexural strength and T150 by 30% and 35%, respectively, compared to UHPC with random finer orientation. Moreover, the synergy of nanomaterial and fiber alignment can lead to a maximum enhancement of 80% and 90% in flexural strength and T150, respectively. Microstructural analysis indicated that CNT and GNP can enhance cement hydration and enable the bridging of cracks at nano or microscale. Moreover, the use of CNT and GNP reduced the porosities of fiber-matrix interface from 6%-12.5% to 4%–7% and UHPC matrix from 5.5% to 4%. This consequently contributed to the significant improvement in mechanical properties of UHPC.