Piezoresistivity of Graphite Modified Asphalt-Based Composites

• Published in: Key engineering materials 2003-01, Vol.249, p.391-396
• Main Authors: Shui, Z.H., Wu, Shao Peng, Mo, L.T.
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.249.391

Asphalt and its composites are electrical insulating materials, whose resistivity ranges from 108#~1013*W. The conductive performance of the asphalt-based composite can be markedly improved with the addition of conductive materials such as graphite. The electrically modified asphalt composites exhibit self-sensing ability to strain, defects, and temperature. Conductive asphalt-based composite would have a profound effect on pavement deicing, damaged testing, highway traffic monitoring and so on. Materials such as Koch AH-70, basalt aggregate, limestone powder and graphite particles were used to prepare a conductive asphalt-based composite in this study. Special attention was placed to its conductive behavior and piezoresistivity. The results show that when the graphite content in asphalt-based composite increases to a critical content, the resistivity declines rapidly. Beyond the critical content, the rate of resistivity varying with the graphite content becomes smooth. Temperature has a remarkable effect on the electrical conduction of the asphalt-based composites. There is a turning point of resistivity with the increase of temperature. Dynamic and static compressive loadings also affect the resistance obviously. The reasons may involve the proximity effect, microcracks and the staggered arrangements of conductive pass-ways.