**Abstract**

Frequency-based damage detection (FDD) has been studied for a long time. Generally, it is pointed out that FDD is less sensitive to detect the damage in civil structures, which are composed of many members precisely. However, for the structural members on the premise of replacement like concrete sleepers, the FDD approach that has been accumulated so far may be effective. In addition, its ease and simplicity of the system are an advantage of realizing regularly and inexpensive inspection on the sites. Here we introduce the damage influence on the concrete sleepers based on the laboratory tests and demonstration of the practical use of FDD through some filed tests.

**Keywords:** concrete sleeper, frequency, damage detection, field test
