EFFECT OF WORKING PARAMETERS ON LUMINANCE VALUES OF TREATED SURFACES ON SURFACE TREATMENT WITH PURE WATER JET

摘要

The stone surface treatment with water jet is a recently introduced method. It is used to increase the roughness to improve its antislip properties while preserving aesthetic appearance of the stone without having thermal shock, mechanical stress and the production of fumes and dust. Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through or is emitted from a particular area and falls within a given solid angle. Luminance is an indicator of how bright a surface will seem and also an aspect reflecting the aesthetical appearance of the surface. The purpose of this study is to investigate the effect of the different working parameters such as traverse velocity, standoff distance and pump pressure on luminance value of treated surface on surface treatment operation with pure water jet by using Italian marble and granite sample commercially named as Green Guatamala and Malaga Grey, respectively. 27 surface treatment tests were performed with a constant nozzle diameter (0.3 mm), distance between jet sweep lines (1.5 mm) and angle of inclination of jet (30°) at varying standoff distances (50, 100 and 150 mm), the traverse velocities (5, 15, 25 m/min) and the pump pressures (200, 250, 300 MPa). As a result of this study, it is found that as the other operational parameters were kept constant, while traverse velocity and standoff distance increase, luminance value of the treated surface decreases, moreover, when pump pressure increases luminance value of the treated surface increases as well.