CHUM Cross Hole Ultrasonic Monitoring system provides information on pile structure without labour-intensive testing operations.
When using CHUM system of pile crosshole monitoring, metal tubes of certain diameter for ultrasonic transducer are preinstalled at all their full length. The quantity of tubes depends on cross sectional diameter of pile.
In practice, piezoelectric and electromechanical converters are used. Acoustic contact is reached by filling tubes with water or nonfreezing liquid (if tests are carried out at a temperature below 0°C). The core of pile integrity testing method using CHUM crosshole monitoring system is in integrity control of concrete cured between tubes. If waves of some defects in concrete are present it reduces propagation velocity of ultrasonic impulse, amplitude and changes the form of the received signal.
Big role in fullest detection of concrete defects play tube arrangement on pile perimeter, their number, material of which they are made and the way they areinstalled on pile length. At installation of tubes it is necessary to keep relative mutual parallelism. To calculate the time of signal passing, its amplitude and velocity to determine numerical values of concrete strength it is necessary to know distance (base) crosshole acoustic measurements. Interpretation of results is based on comparison of the detected anomalies with the ones which were registered in specially constructed test piles with typical defects. When using system of interborehole monitoring of piles of CHUM the defects occupying more than a quarter of section of a pile can be found. Defects are found especially accurately, than closer, they are located to one of tubes.
Carrying out integrity tests using system of interborehole monitoring of piles of CHUM completely conforms to the ASTM D6760-08 standard. Using the software delivered with the equipment, our experts can create the report with the evident providing violation of integrity (figure 1) allowing not only is qualitative, but also quantitatively to estimate the extent of defect of a pile.
Advantages of CHUM (Cross Hole Ultrasonic Monitor)
- Easy to use
- No special training is required – the system is very easy-to-use.
- 2D tomography.
- 3D tomography.
- Three alternative tomography methods: Fuzzy logic, Parametric and 3D.
- In real-time tomography the result is seen as the probes are pulled.
- Modular design.
- CHUM connects to any PC via the standard USB port (pocket PC, netbook, laptop, desktop PC).
- All systems pass pressure, vibration and temperature quality assurance tests.
- High testing productivity.
- One experienced user tests about 700 linear meters of concrete per hour.
- Fully automated reports in MSWord format
- The whole CHUM system can be transported by hand.
- The CHUM is fully compliant to ASTM D6760 – 08.