Xun Yu, Former Associate Professor, UMD-Mechanical & Industrial Eng
This project was an extension of a Northland Advanced Transportation System Research Laboratory (NATSRL) FY09 project, Intelligent Pavement for Traffic Flow Detection, which explored a new approach for detecting vehicles on a roadway by making a roadway section s a traffic flow detector. Sections of a given roadway are paved with carbon-nanotube (CNT)-enhanced pavement; the piezoresitive property of carbon nanotubes enables the pavement to detect the traffic flow. Meanwhile, CNTs can also improve the strength and toughness of concrete pavement. The proposed sensor is expected to have a long service life, possessing a wide-area detection capability and requiring little maintenance. In the FY09 project, lab tests demonstrated that CNT-based cement composite can detect the mechanical stress levels for both static and dynamic loads. In the FY10 project, the research was extended to cement mortar, which has much higher mechanical strength and is more useful in real applications. The effects of the water level and CNT doping levels on the piezoresistivity of the composites were also studied, and preliminary road tests were performed for evaluating this new traffic sensor.