Self-monitoring application of conductive asphalt concrete under indirect tensile deformation

Conductive asphalt concrete has excellent self-monitoring abilities for internal damage and attractive application prospects. By studying the resistance and strain changes under indirect tensile deformation, three distinct stages of output resistivity changes are observed during the destruction of the specimen. In the initial loading stages, contact between the mixture particles tightens because the specimen under loading forms a more conductive path, and the resistivity decreases significantly. In the second stage, asphalt concrete deforms smoothly; small changes in the interior of the asphalt concrete also correspond to small changes in resistivity. In the final stage, because of the progressive development of cracks in asphalt concrete, the specimens are destroyed, and the conductive paths are also seriously damaged, significantly increasing resistivity. This change in the resistivity value exceeds 50%. Conductive asphalt concrete also has a good self-monitoring ability regarding the strain caused by the applied stress. The unit strain corresponding to changes in resistivity is greater when graphite content is lower. CT (Computer Tomography)identification can confirm that changes in resistivity are caused by material changes in the interior due to fatigue failure. The decrease or increase in resistivity is the result of a decrease or increase in the internal porosity of the material.