Flaw detection threshold of thermal integrity testing

The thermal method, based on measuring the hydration temperatures of fresh concrete, is the latest one devoted to testing
the integrity of bored cast in situ piles (drilled shafts). Unlike other methods, it is claimed to cover the whole volume of
the piles, both inside and outside of the rebar cage. The flaw detection capabilities of the method are still undecided,
having been established by a small number of controlled site tests. This document describes a new numerical method
that can simulate the thermal behavior of newly-cast piles of any shape and under any boundary conditions. The results
of a few situations modeled prove that under worst-case scenarios the thermal method is unable to establish the integrity
of the pile skin and may even totally miss a complete discontinuity. It is shown that the method still requires extensive
improvements to qualify as a dependable, user-friendly tool for testing the integrity of concrete piles.