Study on PPP-BOTDA Technology for Concrete Crack Monitoring

Experiment for bare fiber and two kinds of commercial fiber had been done using PPP-BOTDA technology in the paper, and the testing results are analyzed. Experimental results show that different types of fiber have different critical effective sensing length. Despite possessing the 10cm order spatial resolution, if the sensing length of fiber is shorter than the critical value, PPP-BOTDA can not get correct strain. Basing on this experiment result, the concrete crack is simulated and tested. The point fixation bonding method overall bonding method is used in the experiment. The result shows that PPP-BOTDA technology can detect the existence and propagation of crack, and which can even test the width of the crack.