Numerical Study on the Effect of Cracking on Surface Resistivity of Plain and Reinforced Concrete Elements

The effect of discrete cracks on the Wenner probe measurements for surface resistivity of plain and reinforced concrete elements is investigated. A numerical modeling approach is utilized to study the effect of a wide range of parameters that are related to discrete cracks (type, depth, width, location, and orientation with respect to the probe), reinforcement (cover thickness, bar spacing, and bar orientation with respect to the crack), and the Wenner probe (electrode spacing). Depending on the type of the crack and its location, the results indicate that measurements might have errors as much as ∼200% higher or ∼50% lower than the actual resistivity of concrete. Rebar mesh reduces measured resistivity and causes additional error in measurements—the denser the reinforcement, the higher the error. Whereas in most scenarios, crack and rebar mesh affect the accuracy of measurements independently, the effect of deep cracks that surpass the depth of rebars is limited by the presence of rebar mesh. A decrease in electrode spacing would reduce the errors associated with rebar mesh while it increases the impact from the crack; therefore, the common perception of using smaller electrode spacing for error minimization is not valid for reinforced concrete elements with cracks.

Language

  • English

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Filing Info

  • Accession Number: 01564994
  • Record Type: Publication
  • Files: TRIS, ASCE
  • Created Date: Apr 30 2015 3:02PM