Mechanical and Electrical Properties of Multilayer Graphene Composite Conductive Concrete.

As a material for road deicing and snow removal, electrically conductive concrete (ECON) can convert electrical energy into thermal energy to automatically melt ice and snow, avoiding manual and mechanical operations. However, to achieve ideal electrical conductivity, the content of single-doped conductive fillers in ECON needs to be high, which leads to poor workability of ECON and agglomeration of conductive fillers. Combing conductive fillers with different scales helps reduce the content of single-doped conductive fillers in ECON. This study prepared composite conductive concrete using multilayer reduced graphene oxide (RGO), carbon fiber, and steel fiber as conductive fillers. The effect of multilayer RGO on composite conductive concrete's compressive strength, flexural strength, and electrical conductivity was investigated. Besides, the mechanism of RGO on composite conductive concrete's conductive network was analyzed by scanning electron microscope (SEM). Results showed that the 28-day mechanical properties and electrical conductivity of composite conductive concrete first increased and then decreased. Composite conductive concrete containing RGO with 0.4% cement weight (RGO-0.4) exhibited better mechanical and electrical properties. The improvement of the performance of composite conductive concrete was attributed to the filling effect of RGO on the gaps of concrete matrix and the wrapping effect of graphene flocs on fibrous conductive fillers because these effects increased the compactness of the matrix and conductive contact area, respectively. Also, a snow melting test was carried out using an RGO-0.4 slab at an ambient temperature of −15°C. The snow melting efficiency was improved, showing that 20-cm-thick snow melted in 1.2 h. In conclusion, the hybrid addition of RGO and fibrous conductive fillers has positive effects on ECON, providing a new way to develop ECON. [ABSTRACT FROM AUTHOR]