The objective of this research was to quantify the effects of selected parameters on the accuracy of concrete cover measurements on bridge decks. This research involved three full-factorial laboratory experiments each designed to investigate one of three primary variables. These primary variables included distance to a parallel adjacent bar, distance to a reinforcement intersection, and incorrect bar size input for the cover meter. Each experiment also involved four secondary variables known to affect cover readings. These secondary variables included actual cover depth, meter brand, antenna type, and bar size. Statistical analyses were performed to determine the significance of each factor. A margin of error of 0.125 in., corresponding to the increase in diameter between successive U.S. standard rebar sizes, was established as the threshold for practical importance in the data analysis. Three primary findings resulted from the three experiments performed in this research. For the meters and antennas tested, the results of the field-of-view experiment indicated that, if the spacing is greater than approximately 4.0 in., the returned readings are within the threshold for practical importance established for this research. The results of the proximity-to-an-intersection experiment indicated that, regardless of where the measurement is taking place in relation to an intersection, the operator can be confident that the errors will be less than 0.125 in. as long as the bar in question is above the intersecting bar. The results of the wrong-bar-size experiment indicated that, if the operator of the cover meter does not know the actual rebar size in question, the measured cover will be within 0.125 in. of the actual cover depth as long as the meter input is within one bar size of the correct value. Obtaining accurate cover measurements on bridge decks is important for quality assurance, service life prediction, and rehabilitation programming.



College and Department

Ira A. Fulton College of Engineering and Technology; Civil and Environmental Engineering



Date Submitted


Document Type





bridge deck, concrete, concrete cover, cover meter, non-destructive testing, rebar, reinforcing steel