Moisture is a primary contributing factor in the long term durability of bridge decks.
Moisture is involved in freeze-thaw problems in Portland cement concrete and in corrosion of reinforcing steel. Chloride ions, another factor contributing to corrosion, are normally transported through the concrete bridge deck to the reinforcing steel by moisture. Moisture measurement techniques were examined and one of the methods, Peltier-type psychrometers, was used to measure bridge deck moisture. Measurements were made at depths of 0.5, 1.5, 3.0 and 4.5 - 5.5 in. Both negative and positive moment regions were instrumented.