A significant form of deterioration in concrete is corrosion of embedded reinforcing steel
that can cause subsurface delaminations and spalling. Infrared thermography can be used
to detect delaminations based on variations in surface temperature that are caused by the
disruption of the heat flow through the delaminated area. The surrounding environmental
conditions such as sunlight, ambient temperature variation, and wind speed are critical for
heat transfer, and as such the technology depends on these environmental conditions. This
paper describes a numerical model developed to predict thermal contrasts for subsurface
delaminations based on a given set of environmental conditions surrounding the concrete.
The finite element method (FEM) was used to perform 3-D nonlinear transient heat-transfer
analysis of a large concrete block with embedded Styrofoam targets intended to provide an
idealized model of subsurface delaminations. The effectiveness of the modeling was evaluated
by comparing the thermal contrasts predicted by the model and those obtained from
experimental testing of an actual concrete block of the same dimensions. The correlation
and error between the experimental testing and the model results indicated that the model
could be an effective tool for the prediction of anticipated thermal contrasts based on given
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