DURABILITY EVALUATION OF REPAINT-COATING ON STEEL WITH INITIAL PAINT－COATING REMOVED BY INDUCTION HEATING

Repair of damaged paint-coating is an important issue in extending the service life of steel bridges. When repainting the paint-coating, the substrate steel is subject to surface preparation for removing the deteriorated original paint-coating and rust and appropriately making the steel surfaces rough. Although blasting and power tools are used for surface preparation, dust and noise are generated during the work. Therefore, the removal of paint-coating is performed prior to the surface preparation. A new paint-coating removal method by using induction heating (IH) is noted recently. The steel is rapidly heated by IH for removing the paint-coating easily. However, there are many unknowns regarding the influence of IH paint-coating removal on the durability of repaint-coating. In this study, the influence of removing paint-coating by IH on the durability of repaint-coating was evaluated through a series of accelerated corrosion experiments. The results of the 168-day accelerated corrosion experiments showed that the removal of paint-coating by IH did not cause a loss of the durability of repaint-coating compared to the case without using IH for the paint-coating removal.