Roshan Mohammad Jawed, Abedi Mohammadmahdi, Gomes Correia António, Fangueiro Raul
Department of Civil Engineering, ISISE, ARISE, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
Department of Textile Engineering, Centre for Textile Science and Technology, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
Sensors (Basel). 2024 Mar 7;24(6):1737. doi: 10.3390/s24061737.
Numerous elements, such as the composition and characteristics of carbon nanomaterials, the composition and characteristics of the matrix material, moisture levels, temperature, and loading circumstances, influence the piezoresistive behavior of self-sensing cementitious composites. While some past research has explored the impact of some of these factors on the performance of self-sensing cementitious composites, additional investigations need to be conducted to delve into how loading conditions affect the sensitivity of self-sensing cement-stabilized composites. Therefore, this study explores the influences of various loading conditions (i.e., location of loading regarding the location of recording electrodes, and loading level) on the electromechanical performance of self-sensing cement-stabilized sand. To this end, firstly, the evaluation of the percolation threshold based on 10% cement-stabilized sand specimens containing various multiwall carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) was performed. Then, 10% cement-stabilized sand containing 4% MWCNTs/GNPs was tested under various cyclic compressive stresses. The results suggested that the distance between the loading area and the electrode location used for recording the electrical resistance significantly impacted the sensitivity of cement-stabilized sand. Optimal sensitivity was achieved when the electrodes were positioned directly beneath the loading area. Moreover, the study showed that the stress sensitivity of self-sensing cement-stabilized sand increased proportionally with the stress level. An examination through scanning electron microscopy (SEM) demonstrated that the loading condition influences the bridging characteristics of carbon nanomaterials in cement-stabilized sand, leading to diverse electromechanical behaviors emerging based on the loading condition. This study underscores the importance of considering specific parameters when designing self-sensing cement-stabilized sand for application in practical field use.
许多因素，如碳纳米材料的组成和特性、基体材料的组成和特性、湿度水平、温度以及加载情况，都会影响自传感水泥基复合材料的压阻行为。虽然过去的一些研究探讨了其中一些因素对自传感水泥基复合材料性能的影响，但仍需要进行更多研究，以深入了解加载条件如何影响自传感水泥稳定复合材料的灵敏度。因此，本研究探讨了各种加载条件（即加载位置与记录电极位置的关系以及加载水平）对自传感水泥稳定砂机电性能的影响。为此，首先对含有不同多壁碳纳米管（MWCNT）和石墨烯纳米片（GNP）的10%水泥稳定砂试件进行了渗流阈值评估。然后，对含有4%MWCNT/GNP的10%水泥稳定砂在各种循环压缩应力下进行了测试。结果表明，加载区域与用于记录电阻的电极位置之间的距离对水泥稳定砂的灵敏度有显著影响。当电极直接位于加载区域下方时，可实现最佳灵敏度。此外，研究表明，自传感水泥稳定砂的应力灵敏度随应力水平成比例增加。通过扫描电子显微镜（SEM）检查表明，加载条件会影响水泥稳定砂中碳纳米材料的桥接特性，从而导致基于加载条件出现不同的机电行为。本研究强调了在设计用于实际现场应用的自传感水泥稳定砂时考虑特定参数的重要性。
