When inspectors fnd damage, bridge engineers use rehabilitation methods such as bolting steel plates to reinforce cracks or restore corroded sections. Engineers also may use strain gauges, accelerometers, and displacement sensors to monitor crack growth as well as the integrity of repairs. Supported by FHWA’s Exploratory Advanced Research (EAR) Program, researchers at the University of Delaware have developed strong glass fber reinforced plastic (GFRP) composites for the rehabilitation of damaged areas. The GFRP patches developed through this project, “Development of Structural Carbon Nanotube-Based Sensing Composites,” also incorporate electrically conductive carbon nanotube (CNT) networks for monitoring postrepair crack growth
and, thus, provide an integrated strengthening and monitoring system.