Experimental Study on Crack Monitoring of PC Structures with Pulse-prepump BOTDA-based Distributed Fiber Optic Sensors
By Zhishen Wu , Kentaro Iwashita, Songtao Xue and Hao Zhang
Concrete Research and Technology
Vol.18, No.2, May. 2007 (Issue 44)
- Synopsis:
- In our previous study, an investigation on the feasibility of using BOTDR-based distributed fiber optic strain sensors with a minimum spatial resolution of 1m on crack monitoring of RC structures was reported. In the present paper, we examine the effectiveness of PPP-BOTDA (pulse-prepump Brillouin Optical Time Domain Analysis) based distributed fiber optic sensors with a higher spatial resolution of 100mm level, which has been developed newly. Through experimental investigations on the crack initiation, propagation and distribution of two PC beams under static loading and accelerated corrosive action on PC reinforcements by using the PPP-BOTDA based sensors, it is confirmed that the locations of different cracks with about 100mm spacing can be identified individually. And the small strain changes during the occurrence of cracks can be also monitored. Moreover, it is also realized that the overall bonded optical fiber on concrete surface still can not be used to measure quantitatively the cracks even the spatial resolution of PPP-BOTDA has been improved to the level of 100mm.
- Keywords:
- Fiber optic sensors, Pulse-prepump BOTDA, PC structure, corrosion, crack monitoring
