直流电下导电沥青混凝土非线性导电行为研究

导电沥青混凝土中非线性导电行为的导电机制尚不明确。基于实验室制备的碳纤维(CF)–碳纤维粉(CFP)导电沥青混凝土，通过测试外力场对导电沥青混凝土电阻率的关系，结合线性随机电阻网络模型、动态随机电阻网络模型和非线性随机动态电阻器模型，研究导电沥青混凝土非线性导电行为，明确非线性导电行为的导电机制。结果表明：随着碳纤维掺量、油石比和压力的增加，电阻率呈现明显且相似的非线性下降趋势，其中，碳纤维粉掺量的增加导致电阻率先下降后上升；不同掺量的导电沥青混凝土伏安特性曲线均呈现非线性特征；在强电场作用下，导电相材料本身的非线性导电行为和绝缘态部分载流子通道导通引起的非线性导电行为共同导致了碳纤维–碳纤维粉导电沥青混凝土的非线性导电行为，并证明在电场作用下导电沥青混凝土存在隧道效应。

Nonlinear conductive behavior of conductive asphalt concrete under direct current

The conductive mechanism of nonlinear conductive behavior in conductive asphalt concrete is not clear. Based on the laboratory-prepared carbon fiber (CF)-carbon fiber powder (CFP) conductive asphalt concrete, the nonlinear conductive behavior of conductive asphalt concrete was investigated by testing the relationship of the external force field on the electrical resistivity of conductive asphalt concrete, and by combining the linear stochastic resistor network model, dynamic stochastic resistor network model, and nonlinear stochastic dynamic resistor model, to clarify the conductive mechanism of the nonlinear conductive behavior. The results showed that with the increase of carbon fiber content, asphalt-aggregate ratio and pressure, the resistivity shows a significant and similar nonlinear downward trend, and the increase of carbon fiber powder content leads to the first decrease and then increase of resistivity, and the volt-ampere characteristic curves of conductive asphalt concrete with different contents show nonlinear characteristics. Under the strong electric field, the nonlinear conductive behavior of the conductive phase material itself and the nonlinear conductive behavior caused by the conduction of the carrier channel in the insulating state together lead to the nonlinear conductivity behavior of the carbon fiber-carbon fiber powder conductive asphalt concrete, and it is proved that the tunneling effect exists in the conductive asphalt concrete under the electric field.