Repair & Strengthening
With over twenty years of experience in the field of inspection and repair of structures, DSI ofters a complete service package that includes Non-Destructive Testing (NDT) for the non-invasive detection of flaws in structures, in particular, problems of voids in grouted post-tensioning tendons.
DSI also ofters special equipment such as metal sensitive drills and videoscopes for the limited invasive inspection at suspect locations in the structure, digital volumeters that measure the volume of any void inside the tendon and vacuum grouting equipment for subsequent filling of the void.
Non-Destructive Testing (NDT)
DSI's procedures for NDT include locating the ducts in the concrete using Ground Penetrating Radar (GPR), then using Impact Echo instrumentation to determine the location of any voids located inside the grouted tendons.
Grout Remediation of PT Tendons
DSI uses vacuum grouting techniques experienced personnel to fill any voids. As a necessary check, the volume of material injected in the void should be compared to the volume previously measured.
DSI uses only ASBI certified grout technicians cross trained in NDT inspection. All technicians have extensive experience in both pressure and vacuum grouting techniques employing thixotropic grout.
Invasive Inspections
The NDT inspection shall be followed by limited invasive inspection to verify the NDT findings. DSI ofters special devices and techniques developed to minimally invade the structure in order to determine the actual conditions of the grouted tendons and protect the prestressing steel during the inspection.
Volume Measuring
DSI is able to determine the volume of the void through the use of a Digital Volumeter with leak compensating capabilities.
Vibration Testing
Vibration Testing is an economical and efficient procedure used to determine the amount of force existing in external tendons. The method consists of an external sensor located on the tendon to be tested and then generating a vibration in the tendon.
The tendon response is recorded and analyzed with special software that will compute, based on the tendon characteristics, the remaining force in the tendon.