玄武岩-聚丙烯纤维增强混凝土电阻率模型

Resistivity model of basalt-polypropylene fiber reinforced concrete

采用改进二电极交流电法研究了玄武岩-聚丙烯纤维增强混凝土(BPFRC)电阻率,采用压汞试验分析了BPFRC的孔结构。结果表明,相较于未掺纤维混凝土,单掺聚丙烯纤维、单掺玄武岩纤维、混杂纤维0.1%、混杂纤维0.2%电阻率分别提高了11.3%、20.5%、29.4%、-23.0%;相较于C30混凝土,C40、C50电阻率分别提高了18.3%和44.8%。通过孔结构分析发现,除了混杂纤维0.2%,BPFRC少害孔较多,多害孔较少,最可几孔径较小;随着强度提高,孔隙率降低,无害孔增加,多害孔减少,从机理上分析了BPFRC电阻率的差异。基于本文的试验数据,考虑了环境温度、湿度、水胶比及纤维等因素建立了BPFRC电阻率模型。

The resistivity of basalt-polypropylene fiber reinforced concrete(BPFRC)is studied by modified two-electrode alternating current method,and the pore structure of BPFRC is analyzed by mercury injection test.The results show that the resistivity of single mixed polypropylene fiber,single mixed basalt fiber,mixed fiber 0.1%and mixed fiber 0.2%increases by 11.3%,20.5%,29.4%and-23.0%,respectively,compared with that of concrete without fiber.Compared with C30 concrete,the resistivity of C40 and C50 improves by 18.3%and 44.8%respectively.According to the pore structure analysis,except for hybrid fiber 0.2%,BPFRC has more harmless holes,less harmful holes,and the most pore size is small.With the increase of strength,porosity decreases,harmless pores increase,and harmful pores decrease.The difference of resistivity of BPFRC is analyzed from mechanism.Based on the experimental data in this paper,BPFRC resistivity model is established by considering environmental temperature,humidity,water cement ratio,fiber and other factors.