Removal of chlorinated rubber coatings from concrete surfaces using an RF excited CO2 laser

This paper describes the effects of radio frequency excited CO2 laser (RF-C O2) radiation on the material characteristics of white chlorinated rubber ( CR) paint on concrete substrates. Direct laser irradiation of a paint coati ng has been performed. Almost complete removal of the coating with very lit tle to almost no damage (glazing or scabbling) to the concrete substrate ha s been achieved. Performing the process without additional process gas. i.e. purely with an optics shield gas resulted in the generation of a brittle ash layer, coveri ng the coating and shielding it from further laser irradiation. Avoidance o f this was accomplished by introducing a strong airflow parallel to the coa ting surface during the process. This resulted in almost perfect removal of the coating material down to the substrate. The residual ash has been anal ysed via EDX and SEM. (C) 2001 Elsevier Science B.V. All rights reserved.