PhD in Civil Engineering Structures

Nanotechnology for Sustainable Civil Infrastructure Systems

Year of Study: 2

Supervisor(s):

1st Supervisor - Dr. Mohamed Saafi

Keywords:

Carbon Nanotubes, Crack Detection, Self-sensing material, Structural health monitoring, Wireless sensors.

Abstract

Civil infrastructure systems suffer damage due to loading and environmental effects. Most civil structures need repair and rehabilitation throughout their lifecycle; if damaged and left untreated the cost of repair can spiral upwards. Early indication of this damage could help lower costs and fix the problem before any major damage materializes.

One new potential application of nanotechnology is advanced sensors to monitor the structural integrity of structures. This structural integrity monitoring will allow for early detection of crack propagation, thus allowing for repair which could reduce costly repairs and in the worst case future catastrophic failure. The structural integrity system that is suggested here is the use of carbon nanotubes mixed into paint and applied to a structure; then an electrical current is passed through the paint where the electrical resistance can be monitored. If cracks propagate, the electrical resistance of the nanotubes change when bending occurs; this will change the electrical resistance of the paint indicating a crack has formed in the structure. This information can be wirelessly sent to a computer where an FE model can be updated to simulate the effect of the damage. If this system can be implemented throughout the whole structure, real-time damage status can be monitored similar to the human brain sensing damage as it happens. This system can provide wireless real time data that can monitor damage escalation. The advantage of wireless sensors in this application is that they can be manufactured in high volumes, at low cost with excellent performance in a minute footprint. Wireless sensor networks are becoming a realistic option for remote monitoring of large scale structures located in harsh environments.