NOVEL FIBER COMPOSITES FOR SIMULTANEOUS STRENGTHENING AND STRUCTURAL HEALTH MONITORING OF STEEL STRUCTURES

摘要

As civil infrastructure continues to deteriorate and remain in service beyond the initial design life, there is a critical need for developing innovative techniques that allow for rehabilitation and monitoring simultaneously. In particular, there are numerous steel bridges with corrosion and fatigue-related problems that need urgent attention. Our research aims to create a unique solution where structural fiber composites are integrated with carbon nanotube (CNT)-based sensors to form a novel structural sensing composite. Adhered to structural steel members, the structural carbon fiber layers of the composite reduce the stress level in the steel by sharing the load and the sensing layer enables continuous detection of strain and damage in the composite. Such capability would be effective for retrofitting structures and monitoring potential crack propagation over time. Furthermore, the sensing layer is capable of distributed sensing which provides improved health monitoring compared to discrete point sensors like strain gages. In this paper we introduce the concept, manufacture a prototype sensing composite, and conduct laboratory-scale experiments to examine the load-carrying and strain/damage sensing response on a steel tensile specimen.