ADVANTAGE OF GBARZ (GALVANIZED REBARS) OVER EPOXY COATED REBARS ECR (Epoxy Coated Rebars)

1) Special Handling

The zinc coating of GBARZ (Galvanized Reinforcement Bars) is harder than the steel itself. Bundling, dragging and rough treatment prior to and during placement have no effect on GBARZ (Galvanized Reinforcement Bars).

ECR (Epoxy Coated Rebars) requires delicate handling to prevent damage to the epoxy coating. Any damage to the coating prior to placement will compromise the corrosion protection.

2) UV Damage

GBARZ (Galvanized Reinforcement Bars) is unaffected by UV rays exposure during field storage and installation period.

ECR (Epoxy Coated Rebars) coating break down under UV rays exposure.

3) Touch-up

GBARZ (Galvanized Reinforcement Bars) coatings are impact and scratch resistant to support any mode of shipping and placement.
Only cut ends need touch-up in the field because of cathodic protection ability of zinc.

In case of ECR (Epoxy Coated Rebars) the entire rebar may corrode below the coating itself which may not be corrected by mere touch up.

4) Overlap Lengths

GBARZ (Galvanized Reinforcement Bars) have equal or better bond strength in concrete not requiring any additional overlap lengths

American concrete Institute (ACI 318) recommends 20% more overlap lengths while
using ECR (Epoxy Coated Rebars). This is because bond strength of ECR (Epoxy Coated Rebars) is far less in comparison to black steel.

5) Holidays / Pinholes (Coatings Inconsistencies)

HDG specifications do not allow any uncoated surface areas post galvanizing. The HDG process ensures 100% of the Re-bar is coated with zinc.

ECR (Epoxy Coated Rebars) specifications allow for a certain percentage of the bar to have holidays and pinholes, compromising its protection mechanism before it even reaches the job site.

6) Bond to Concrete

There is no significant difference at ultimate load between the bond strength of GBARZ (Galvanized Reinforcement Bars) and black rebar.

ACI Code requires the basic development length for ribbed epoxy-coated bars to be Increased due to the loss of bond strength of the epoxy coating.

7) Fabricate After Coating

GBARZ (Galvanized Reinforcement Bars) can and is often fabricated / bent after galvanizing.

ECR (Epoxy Coated Rebars) is not practically fabricated after coating as the epoxy will crack / flake off.

8) Underfilm Corrosion

The zinc of GBARZ (Galvanized Reinforcement Bars) is self-healing and impermeable. If GBARZ (Galvanized Reinforcement Bars) is damaged, there is only small, localized Corrosion.

ECR (Epoxy Coated Rebars) coatings are permeable and once corrosion begins, it spreads throughout the bar underneath the epoxy film.

9) Cathodic Protection

GBARZ (Galvanized Reinforcement Bars) offers sacrificial protection to the steel. GBARZ (Galvanized Reinforcement Bars) prevents corrosion in chloride ion concentrations 2 to 5 times greater than what causes corrosion of black Rebar. GBARZ (Galvanized Reinforcement Bars) also provides barrier protection against impact.

ECR (Epoxy Coated Rebars) offers only barrier protection that is compromised by allowing a percentage of pinholes and holidays in the coating.

10) Abrasion Resistance

GBARZ (Galvanized Reinforcement Bars) coating (Alloy layers) are harder than the substrate steel with a hardness ranging from 179 to 250 DPN (Diamond pyramid number)

ECR (Epoxy Coated Rebars) must be handled with extreme care of avoid coating damage.

11) Installation Conditions

GBARZ (Galvanized Reinforcement Bars) can be handled in all temperatures.

ECR (Epoxy Coated Rebars) Coating may crack when handled in temperature less than 50 F

12) Accelerated Performance Tests

Real- works performance (< 30 years) shows GBARZ (Galvanized Reinforcement Bars) passivates after curing of concrete producing zinc corrosion products that migrate from the concrete matrix (no Cracking /spalling pressure is created ) and has higher threshold for chloride & CO2 corrosion.

ECR (Epoxy Coated Rebars) performance is largely on accelerated salt spray test on real time baisis. The artificial conditions of salt spray tests accelerate only one parameter and monitor corrosion, which does not however mimic real world conditions.