Research on the self-sensing and mechanical properties of aligned stainless steel fiber-reinforced reactive powder concrete
Research on the self-sensing and mechanical properties of aligned stainless steel fiber-reinforced reactive powder concrete
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DOI：
10.1016/j.cemconcomp.2021.104001
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发表时间：
2021-05
影响因子：
10.5
通讯作者：
Hui Wang;Feiting Shi;Jia-Man Shen;Ai-lian Zhang;Lin-chun Zhang;Huanghuang Huang;Junzhe Liu;
中科院分区：
文献类型：
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作者：
Hui Wang;Feiting Shi;Jia-Man Shen;Ai-lian Zhang;Lin-chun Zhang;Huanghuang Huang;Junzhe Liu;
将不锈钢纤维（SSFs）掺入活性粉末混凝土（RPC）中，制备了定向排列（通过L型装置改进）和随机定向分布的SSFs导电RPC。SSF的长径比范围为30 ~ 150，SSF的含量为RPC体积的0.2%~ 1.2%。RPC的养护龄期为7 ~ 60 d。研究了样品的导电性能（电阻和交流阻抗）、超声波通过样品的速度和随后的压阻率。并对养护60 d后的试件进行了抗压强度、抗折强度和韧性测试。最后，获得了SSF的分散和取向的高分辨率图像。结果表明，SSFs-RPC的声速和电阻随养护龄期的增加呈二次函数增长。SSFs-RPC的逾渗阈值为0.4%。此外，具有较高长径比和定向纤维的RPC具有更好的导电性、压阻性和力学性能。SSFs-RPC的导电机理可以通过三个串联电元件的导电模型来解释。图像分析表明，长径比越大的SSF在RPC中分散越均匀，L型装置能有效地改善纤维的排列。
Stainless steel fibers (SSFs) were added into reactive powder concrete (RPC) to fabricate aligned (improved by L-shaped device) and random directional distributed SSFs conductive RPC. The aspect ratio of SSFs ranged from 30 to 150, while the SSFs amount was 0.2%–1.2% by volume of RPC. Curing ages for RPC ranged from 7 d to 60 d. The conductive performances (electrical resistance and AC impedance spectroscopy), the speed of ultrasonic passing through specimens and the following piezoresistivity were investigated. Moreover, the compressive strength, flexural strength and toughness of specimens cured for 60 d were tested. Finally, high-resolution images of SSFs’ dispersion and orientation were gained. Results showed that the ultrasonic velocity and electrical resistance of SSFs-RPC grew in the form of a quadratic function with the increasing curing ages. The SSFs content of 0.4% was the percolation threshold value of SSFs-RPC. Additionally, RPC with higher aspect ratio and aligned fibers performed better conductivity, piezoresistivity and mechanical performance. The conductive mechanism of SSFs-RPC can be explained through the conduction models of three series connected electrical components. The image analysis showed that SSFs with higher aspect ratio dispersed more uniformly in RPC and the L-shaped device could effectively improve the alignment of fibers.