Coated bars with damaged coatings initiate corrosion at chloride contents within concrete that are several times greater and corrode at rates that are typically two orders of magnitude below those exhibited by conventional reinforcement.
Research findings on conventional reinforcement, cracks, epoxies, reduced water-cement ratio, corrosion inhibitors, reinforcement with multiple coatings, coated bars, and adhesion reductions also are discussed in this TechBrief, which is available at www.
Other new lines under the Classic banner are Raisin Crisp and two dark chocolate coated bars
, Dark & Citrus and Dark & Coffee, all at rsp 25p.
Earlier FHWA studies, The Performance of Bendable and Nonbendable Organic Coatings for Reinforcing Bars in Solution and Cathodic Debonding Tests (FHWA-RD-94-103) and Degradation of Powder Epoxy-Coated Panels Immersed in a Saturated Calcium Hydroxide Solution Containing Sodium Chloride (FHWA-RD-94-174), showed that the adhesion properties of the coated bars
, as tested by solution immersion and cathodic disbondment tests, could not predict the rate of corrosion or the long-term performance of ECRs in chloride-contaminated concrete.
These results and earlier FHWA studies indicate that adhesion appears to be a poor indicator of long-term performance of coated bars
in chloride-contaminated concrete, as no direct relationship exists between loss of adhesion and the effectiveness of ECR to mitigate corrosion.