In most countries in the north, the rainy and snowy weather in winter is likely to cause snow in the road area to be frozen, so that the adhesion of the vehicle tires to the ground is reduced, the danger of driving is also increased, and the smooth traffic is also severely affected. According to statistics, 15%~30% of winter traffic accidents are related to road area snow icing. In order to solve the severe traffic safety problems caused by snowy roads, people actively explored and tried many methods.
With the development of science and technology and the continuous discovery of new materials, some scientists have boldly imagined that if the road is paved with conductive concrete, when the ice and snow pile up, as long as the road is energized and heated, it can quickly melt the ice and snow and solve the problem of road slippery. Keep traffic safe and smooth.
In 1980, some developed countries began to explore the feasibility of conductive concrete and studied its preparation technology. In the 1970s, the United States and the Nordic countries introduced the research and application of conductive concrete in order to solve the problem of road and bridge concrete corrosion caused by deicing salt. In the late 1990s, the study of conductive concrete began to be gradually applied in practice. In 1998, China tried to incorporate graphite into cement paste to make indoor heating floors, which was very satisfactory. In 2003, the United States applied conductive concrete to the deck of the Roca Spur Bridge, using its thermoelectric effect to deicing snow. These research results show that conductive concrete has solid prospects, and it is extremely feasible to apply to melt ice and snow.
Graphite is a relatively easy-to-obtain inorganic material that has not only good electrical and thermal conductivity but also has excellent chemical inertness. Studies have shown that the electrical resistivity of conductive commercial concrete can vary from 10-1 to 106 Ω·cm with the change of graphite content. However, it is necessary to make the commercial concrete have good conductivity when the content is high, and the graphite powder The water demand is significant, and it is necessary to increase significantly the water consumption of the commercial concrete mixture, which will cause the strength of the commercial concrete to decrease as the amount of graphite powder increases rapidly. When the content of graphite exceeds 12%, the increase of electrical conductivity is not apparent, while the compressive strength decreases sharply with the increase of graphite content. When the amount of graphite is more than 20%, the compressive strength is less than 10MPa, and the resistivity is less than 10MPa. Less than 50 Ω·cm.
The incorporation of graphite powder makes the workability of the concrete mixture worse, but it can meet the requirements of engineering construction. As the amount of graphite powder is increased, the strength of conductive concrete decreases; the fineness of graphite powder has little effect on the strength of conductive concrete. The electrical resistivity of the conductive concrete decreases with the increase of the fineness and the amount of the graphite powder. After continuous energization, it has an excellent electrothermal effect and a power generation effect. Conductive concrete with excellent workability, strength, and electrical conductivity can be prepared by using graphite powder. The conductive concrete is mixed into ordinary concrete, and the concrete is transformed into a new composite material with specific conductivity. After the power is turned on, the concrete is energized and heated. As the temperature of the road surface rises, the snow and ice are melted by heat. Conductive concrete can melt snow in a timely and efficient manner, ensure smooth traffic and safety, reduce national economic losses caused by ice and snow disasters, be green, and meet the requirements of sustainable development. As a new type of composite functional concrete, it not only has the superior mechanical ability of ordinary concrete, but also has good electrical conductivity and thermal conductivity; it can effectively avoid the traffic accident risk caused by snow and ice in winter road area and can solve the deicing salt. The economic and environmental problems brought about have good application prospects.