Nondestructive evaluation for performance of civil structures. An overview of activities in the Federal Republic of Germany

The contribution refers the needs for ndt in civil engineering as a tool of quality assurance as well during the fabrication of components and structures, bridges, buildings, etc., as well for maintenance and inservice inspection. The emphasis is especially to present the state of the art to some new techniques which are in the state of development, and the state of the art of techniques which are ready for use. X-ray-, Gamma-ray- and LINAC -inspection is mentioned and the applicability of ultrasonic inspection of concrete is discussed. The induction thermographic technique and a new magnetic leakage flux approach are refered which allow the detection of reinforcement bars and the coverthickness measurement. The use of optical wave guides is an approach to control the prestress-state in concrete super-structures. (IZFP)