Distributed fiber optic sensing for crack detection in concrete structures

The method of fiber optic strain measurement offers promising perspectives for experimental research and also provides extensive new capabilities for the systematic monitoring of engineering structures. A robust but sufficiently sensitive configuration of measuring device and passive optical fiber is desirable in practical application. In this context, a total of five different optical measuring fibers were analyzed at the Chair of Concrete Structures at the Technical University of Munich (TUM) for different application variants using two measuring instruments on a prestressed concrete beam. Fiber optics, supplemented by conventional measuring technology, was able to detect elastic strain, crack formation, and decisive shear cracks of the fracture state.