Self-sensing conductive asphalt concrete for real-time monitoring of internal damage evolution

The advent of self-sensing materials offers a promising approach for monitoring internal damage in pavements. This paper explores the use of conductive asphalt concrete to enable real-time monitoring and quantitative assessment of internal damage evolution. A conductive-damage model for asphalt concrete is proposed, followed by laboratory tests to monitor the fractional change in electrical resistance (FCR). Finally, the model's applicability and sensitivity for damage monitoring are analyzed. Results indicate that the proposed conductive-damage model can effectively predict internal damage in materials subjected to both monotonic and fatigue loading. Laboratory tests reveal that the spatial network of the binder in the asphalt concrete significantly affects the distribution of the conductive medium, leading to non-uniformity and randomness of specimens' conductive pathway. The conductive-damage model effectively facilitates the quantitative evaluation and monitoring of the continuous internal damage evolution in the asphalt concrete.