This report provides documentation and example results for a computer model developed to predict the surface temperature and time-of-wetness (and time-of-freezing) of concrete pavements and bridge decks. The model is based on a one-dimensional finite difference scheme and includes heat transfer by conduction, convection, and radiation. Environmental conditions are varied by using the typical meteorological year datafiles available from the National Renewable Energy Laboratory. Based on the weather data available in these files and the developed heat transfer model, both the surface temperature and the time-of-wetness of the concrete are computed for typical pavement and bridge deck structures. The time-of-wetness includes both precipitation and condensation on the concrete surface. These predictions will be utilized as input into sorptivity-based service life models for sulfate attack and freeze/thaw deterioration, which is the main goal of the NIST research project being funded by the Federal Highway Administration.
Keywords: Bridge decks, building technology, computer modeling, concrete, heat transfer, pavements, surface temperature, time-of-wetness.