Abstract In this study, the pressure sensitivity and temperature sensitivity of the diphasic electric conduction concrete were investigated by measuring the resistivity using the four-electrode method. The diphasic electric conduction concrete was obtained by mixing nano and micro conductive materials (carbon nanofibers, nano carbon black and steel slag powder) into the carbon fiber reinforced concrete (CFRC). The results indicated that, with the increase of conduction time, the resistivity of CFRC decreased slightly at the initial stage and then became steady, while the resistivity of CFRC containing nano carbon black had a sharp decrease at the dosage of 0.6%. With the increase of compression load, the coefficient of resistivity variation of CFRC containing nano carbon black and steel slag powder changed little. The coefficient of resistivity variation increased with the increase of steel slag powder in the dry environment, and CFRC had preferable pressure sensitivity when the mass fractions of carbon fiber and carbon nanofiber were 0.4% and 0.6%, respectively. Besides, in the humid environment, the coefficient of resistivity variation decreased with the increase of steel slag powder, and the diphasic electric conduction concrete containing 0.4% carbon fibers and 20% steel slag powder had the best pressure sensitivity under the damp environment. Moreover, in the dry environment, CFRC containing nano and micro conductive materials presented better temperature sensitivity in the heating stage than in the cooling stage no matter carbon nanofiber, nano carbon black or steel slag powder was used, especially for the CFRC containing steel slag powder.

中文翻译：

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纳米和微导电材料对碳纤维增强混凝土导电性能的影响

摘要 本研究采用四电极法测量电阻率，研究了双相导电混凝土的压力敏感性和温度敏感性。双相导电混凝土是通过将纳米和微导电材料（碳纳米纤维、纳米碳黑和钢渣粉）混合到碳纤维增强混凝土（CFRC）中而得到的。结果表明，随着导电时间的增加，CFRC的电阻率在初始阶段略有下降，然后趋于稳定，而含纳米炭黑的CFRC的电阻率在0.6%的用量下急剧下降。随着压缩载荷的增加，含纳米炭黑和钢渣粉的CFRC电阻率变化系数变化不大。电阻率变化系数随着钢渣粉在干燥环境中的增加而增加，当碳纤维和碳纳米纤维的质量分数分别为0.4%和0.6%时，CFRC具有较好的压敏性。此外，在潮湿环境下，电阻率变化系数随着钢渣粉的增加而降低，含0.4%碳纤维和20%钢渣粉的双相导电混凝土在潮湿环境下的压敏性最好。此外，在干燥环境下，无论是使用纳米碳纤维、纳米碳黑还是钢渣粉，含纳米和微导电材料的CFRC在加热阶段都比在冷却阶段表现出更好的温度敏感性，尤其是对于含钢渣粉的CFRC .