Synthesis, characterisation and performance of piezo-resistive cementitious nanocomposites

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• 作者：Saptarshi Sasmal ; ^{saptarshi@serc.res.in} ; ^{sasmalsap@gmail.com} ; N. Ravivarman ; B.S. Sindu
• 关键词：Multi walled carbon nanotubes (MWNTs) ; Surfactant ; Dispersion ; Cyclic loading ; Piezo-resistivity ; Conductance ; Nano-composite
• 刊名：Cement and Concrete Composites
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：75
• 期：Complete
• 页码：10-21
• 全文大小：2940 K
• 卷排序：75

文摘

Smart material reinforced non-destructive structural health monitoring technique has been evolving as the most predominated route for assessing the performance of the civil structures. In the present study, multiwalled nanotubes (MWNT) were suitably incorporated into the cement matrix, which act as actively embedded sensor for monitoring real-time flaws in structures. Initially, the stable homogenous MWNT dispersion was prepared by using ionic surfactant technique with high-intensity ultrasonic agitation process. Since, a suitable and adequate synthesis procedure to incorporate MWNT in cement matrix is essential, but complicated, the role of amplitude and frequency of sonication on dispersion of nanotubes was categorically evaluated. Further, this paper focuses to find out the effect of surfactant on MWNT dispersion by using the UV Visible spectroscopy and by evaluating the effective hydro-dynamic diameter. Based on micromechanics based analytical model, the influence of the interface layer thickness and geometrical configuration of nanotubes on the electrical conductivity of cement nano-composite are also analyzed. Further, the electrical conductivity of MWNT incorporated cement system, as developed in the present study, is measured using four probe method. Piezo-resistivity of the oven dried samples is measured to evaluate the change in potential drop under cyclic loading regime. It is found that the efficiency of the piezo-resistive strain sensors greatly depends on synthesis process and the circuit system. Appropriately proportioned and properly synthesized MWNTs incorporated in cement matrix were capable of providing consistent and steady response under the variable external stress. Thus, the material can be used as embedded sensor for health monitoring and identifying initiation of any damage in reinforced concrete structure.