The Centre for Characterization and Microscopy at Polytechnique Montréal recently tested representative samples of traditional Hot-dipped galvanized steel rebar and a proprietary rebar product made using a continuous galvanizing process (CGR).

The Hot-dipped zinc coating was found to be far thicker than that of the proprietary CGR rebar while being of similar purity.

In addition, CCM took micrographs of the microstructure of both HDG and CGR using a scanning electron microscope (SEM). The micrographs show that HDG was far less porous than CGR. High porosity allows chloride ions to penetrate the zinc layer and attack the underlying steel bar. 

CGR rod