Determination of reinforced concrete durability with on-site resistivity measurements

Concrete quality can be tested on site by coring or non-destructive testing. This paper describes a method based on the four-point or Wenner procedure for measuring electrical resistivity, deployed on a bridge over the River Danube between Vidin, Bulgaria and Calafat, Romania. Due to the high reinforcement density in bridge members, a model had to be developed to measure resistivity in the concrete cover and the instruments conventionally used had to be modified. The findings for the over 900 measurements recorded, which covered most of the bridge, showed that the concrete quality was higher than specified in 99.25 % of the readings.