We utiize NO-DIG technology, which was developed based on NTT's R & D results, to continue to take part in improving social infrastructure efficiency, as well as to contributing to global environmental protection.
Non-destructive testing technique for determining if grout has been completely filled
A non-destructive testing technique which uses the elastic impact wave method to determine if the grout in the sheathing tube of a PC internal bridge has been sufficiently filled.
■The grouting condition can be tested without destroying or filing down the bridge.
■The test is done by just attaching the necessary equipment and striking with a hammer.
■It is possible to determine if it has been completely filled with just the shape and velocity of wave propagation.
When the grout is not completely filled (there are empty spaces in the sheathing tubes), "high frequency components" can be observed in the wave propagation shape.
【When grout is not completely filled】
【When grout is completely filled】
