The Thermal Integrity Profiler (TIP) uses the heat generated by curing cement to assess the quality of drilled shafts and of bored, augered cast in place, continuous flight auger or drilled displacement piles. It may also be used for quality control and shape evaluation of jet grouting, slurry walls and diaphragm walls. TIP evaluates the entire cross-section and the entire length of the foundation by the Thermal Testing Method. Results are available shortly after shaft installation is concluded.
The average temperature within a concrete shaft is dependent on its diameter, on the concrete mix design and on the time of measurement relative to concrete casting. Measured temperatures at the reinforcement cage vary with the distance to the center of the shaft and with the concrete cover.
Through field measurements and data interpretation software, TIP reveals:
- Necks or inclusions (regions that are colder than average)
- Bulges (regions that are warmer than average)
- Variations in concrete cover
- Shape of the shaft
- Cage alignment
TIP is available in two models: with Probes1 or with Thermal Wire® 2 brand cables.
The TIP Probe Model includes a thermal probe (with 4 orthogonal temperature sensors) that is inserted into access tubes for data collection, and a Thermal Acquisition Port that transfers collected data to the TIP main unit. Shafts must be built with access tubes to be tested with this system.
The TIP THERMAL WIRE Model includes a starter set of THERMAL WIRE cables (copper cables fitted with uniformly spaced temperature sensors), and Thermal Acquisition Ports that transfer collected data to the TIP main unit. The cables are cast into the shaft (often tied to the rebar cage). An additional short THERMAL WIRE cable may be installed parallel to one of the main cables to help, refine the estimate of the concrete cover.
Data collected by either TIP system is downloaded to a computer for analysis by the TIP Reporter Software. The TIP Reporter Software displays measured temperatures versus depth and mapped on cross sections of the shaft. A straightforward examination of these graphical representations is often sufficient to indicate a shaft with no integrity issues or one with defects.
The Thermal Profiling Method was developed at the University of South Florida and originally implemented by FGE. Current research and development is a joint effort of FGE and PDI.
1Mullins, A. G. and Kranc, S. C., (2004), "Method for Testing the Integrity of Concrete Shafts," US Patent 6,783,273.
2Cotton, D., Ference, M., Piscsalko, G., and Rausche, F., (2010) "Pile Sensing Device and Method of Making and Using the Same" US Patent 8,382,369.