Characteristics of high power diode laser removal of multilayer chlorinated rubber coatings from concrete surfaces

This paper reports the technical feasibility and process characteristics of removing chlorinated rubber (CR) coatings from concrete surfaces utilising a 60 W continuous wave (cw) diode laser operating at 810 nm wavelength. Co ating layers of various thickness have been removed under an oxygen shroud- gas, as well as Ar and Nz. Optical microscopy and energy dispersive analysi s of X-rays (EDX) have been utilised to verify this. The reflectivity prope rties of the CR material from the visible to the near infrared wavelengths, as well as their behaviour under high temperatures have been examined with a normal incidence spectrometer and a differential thermal analysis/therma l gravimetric analysis (DTA/TGA) system. The resulting drop in reflectivity explains the possibility of sustaining the combustion, even though the ref lection coefficient of white CR at 810 nm is almost 100%. (C) 1999 Elsevier Science Ltd. All rights reserved.