The Thermal Integrity Profiler (TIP) is a new solution for evaluation of bored piles that bases its diagnosis on the heat generated by curing cement. The system has been jointly developed by Pile Dynamics and Foundation & Geotechnical Engineering based on research conducted at the University of South Florida.
According to Pile Dynamics, the temperatures within a curing concrete pile is dependent on its diameter, distance from the point of measurement to the centre and on the volume of concrete surrounding the measuring point. Concrete voids will result in temperatures that are lower than expected, while more
concrete near a measuring point makes it warmer than average. Given these facts, TIP estimates the actual shape of the foundation, including the previously difficult-todetermine thickness of concrete cover and cage alignment.
Pile Dynamics believes that the TIP is attractive because it assesses the concrete quality of the entire cross section (not just within the reinforcement cage) and along the entire length of the foundation.
“Another major advantage is its early testing time - test results are available as early as 12 hours after concrete is poured, allowing construction to continue,” said Pile Dynamics’ Mattias Grävare.
“Two types of data acquisition systems are available: thermal probe and thermal wires. In the first method, a probe fitted with infrared thermal sensors is inserted in Crosshole Sonic Logging (CSL)-type access tubes. Data acquisition is repeated once per tube, unlike in CSL where the test is repeated for all possible combinations of pairs of tubes, making TIP a faster method.
“Alternatively, and preferably, thermal wires are attached to the reinforcement cage prior to concreting, and data acquisition is automated,” said Grävare.”Measurements obtained by either system are collected by thermal acquisition ports, transferred to the main unit of the TIP, and downloaded to a computer. An engineer then further analyses the data with the TIP reporter software, which graphically represents the shape of the shaft and pinpoints potential problem areas.”