Corrosion Behaviors of Arc Sprayed Zinc Coating under Asphalt Concrete Coat on Long-span Steel Box Bridge Deck

The corrosion behaviors of zinc coating under asphalt concrete coat on long-span steel box bridge deck were studied by means of electrochemistry workstation instrument,SEM,XRD and fatigue testing.The behaviors of impedance,polarization properties,corrosion potential,corrosion appearance and corrosion products were investigated for zinc coatings under the conditions of scoring bond coat,disbond coat and fine bond coat.The zinc corrosion grade under scoring coat was higher than that under peeling coat,and the shearing resistance was about one time lower than that for asphalt concrete coat-asphalt bond coat-zinc anticorrosion coat of steel brigde deck system,A great lot of ZnO,Zn5(CO3)2(OH)6 and Zn5(OH)8Cl2 H2O were found in the corrosion products ,the zinc corrosion rate was controlled by the charge transfer and ion diffuseness,the zinc coat corrosion under asphalt concrete coat accelerated its displacement and cracking.