Distributed fiber optic sensing technique is being considered as a promising method to monitor continuously structural behavior such as the detection of crack, and the measurements of crack widths and overall deformation with a real-time manner, because current structural inspection technologies are not capable of responding to many of the monitoring needs pertinent to concrete structures. In this paper, in order to investigate and improve the monitoring capability of fiber optic sensors with BOTDR, first of all, several kinds of installation methods are proposed. Moreover the effectiveness is verified through testing instrumented RC beam specimen where the fiber optic cable is installed with the proposed methods. It is realized that the loop type of installation methods of fiber optic sensors can be effectively used to measure the crack damage within a relatively local area and the fixed point installation method of fiber optical sensor is capable of measurement of strain due to one or two localized cracks within a distance of lm resolution.
