Abstract
This paper describes a removing method the graffiti drawn on the surface of concrete without hurting the surface, using the Laser. The graffiti was drawn to the concrete surface with a water spray (black, red and blue). And the graffiti were removed by a YAG Laser and a High–power Laser diode. As a result, the black graffiti is removed to the ΔE10 of the color different by the YAG Laser, the blue graffiti is removed to the same value is ΔE, as the black graffiti by the high–power Laser diode. The paper is deal with relationship between kind of Laser and color of graffiti. The nine colors (red, bitter orange, yellow, green, blue, indigo, purple, black and white) of paint and 3 types of Laser (YAG Laser, High–power Laser diode and CO² Laser) and provided for the test. The well removing color and Laser are shown. It is what gives scribbling to the concrete test body by nine kinds of in total white, seven kinds of colors with different wavelength (red, bitter orange, yellow, green, blue, indigo, and purple) it and achromatic colors black colors, and examined it about the color of the kind of the Laser and scribbling removed easily in this report.
