Developments of Conductive Materials and Characteristics on Asphalt Concrete: A Review

Abstract The requirements for modified asphalt concrete are increasing because of heavy traffic load and worsening service environments in modern highway construction. More and more attention has been paid to the development of multifunctional asphalt concrete. Conductive asphalt concrete exhibits specific characteristics and incredible novel features, such as self-diagnosis and monitoring, self-healing, and snowmelt, etc. It has the potential to satisfy multifunctional applications. This article summarizes the major achievements of the existing literatures about conductive asphalt concrete, including material design, mechanism analysis, performance evaluation and engineering applications, and gives some proposals for further investigations. The article shows that the conductivity and mechanical properties of conductive asphalt concrete are strongly dependent on the compositions of the material. Meanwhile, the mechanism of conductivity improvement is identified according to the characteristics of conductive additives. Although conductive asphalt concrete has some shortcomings and few applications in the highway industry, it shows some appreciable advantages in aspects such as environment protection and traffic safety. The purpose of this review article is to provide the reference and guidance for researchers to discover proper material design, novel properties, durability, and desirable high operational efficiency, as well as suitable construction technique.