Nachweis der Firstspaltverpressung bei zerstörungsfreien Schalendickenmessungen an Tunnelinnenschalen

Verification of Ridge-Gap Grouting by Measuring the Shell Thickness of the Inner Tunnel Layer by Non-Destructive Testing

Previous evaluations of various tunnel projects showed results where the ridge-gap grouting of the inner tunnel shells was not always been non-destructively proven. In areas which, for example, have to be repaired through exposed reinforcement in the ridge, the proof of the grouting material is of great importance. This problem was explored experimentally in laboratory tests on concrete test specimens through variation of different actuating variables and parameters. Afterwards, the experimental results were put into practice in areas of detected flaws in the ridge area on a tunnel construction site. The inner tunnel shell with the grouting material could be proved perfectly non-destructively by using special grouting material and pre-treatments in this area.