Research on Electrical Conductivity and Mechanical Properties of Ecological Concrete Prepared from Mine Solid Waste

Conductive concrete with nanographite–cupric nickel sulfate ore was prepared in this paper. As a new type of multifunctional multiphase conductive building material with conductive, electrothermal, electromagnetic shielding, piezoresistive properties, etc., nanographite–cupric nickel sulfate ore conductive concrete will have a wide range of applications in snow melting, electromagnetic shielding, cathodic protection and structural health monitoring, and other fields. In this paper, different dosage of nanographite and cupric nickel sulfate ore admixture that the mixture was excited by alkali excitation, ultrasonic vibration and combined alkali excitation and ultrasonic vibration, respectively were used to study the electrical conductivity and mechanical properties of conductive concrete, 36 groups of nanographite–cupric nickel sulfate ore conductive concrete specimens and seven groups of comparative specimens were cured for 28 days, and the unconfined compression test, three-point bending test, and electrical conductivity test were carried out. The results show that the electrical conductivity and mechanical properties of the specimens with 6% nanographite and 60% cupric nickel sulfate ore were the best, with the compressive strength, flexural strength and resistance reaching 40.83 MPa, 6.81 MPa, and 5,850 Ω·cm, respectively. Compared with the comparative specimens, the compressive strength and the flexural strength of the specimens are increased by 38.5% and 20.4%, respectively, and the resistivity is decreased by 55.7%. This shows that the alkali excitation-ultrasonic vibration activation method can not only improve the electrical conductivity of nanographite–cupric nickel sulfate ore conductive concrete pavement but also ensure the stability of its mechanical properties.