Figure 1. Bethlehem bridge deck spalled and delamination areas.

A pachometer was used to determine the depth of concrete cover over the reinforcing steel. Forty measurements were taken, 20 within and 20 outside of the impregnated area. The mean depth of cover is 1.45 in. with a standard deviation of 0.40 in. and a range of 1.00 in. to 2.00 in. Thus, the depth of cover is relatively small which would account for the premature deterioration of the deck concrete.