Author
CORONADO MARTIN, J. A.
Technical University of Madrid (U.P.M.)
GARCIA SANTOS, A.
Technical School of Architecture (E.T.S.A.M.)
ADELL ARGILLES, J. M.
Department of Construction and Technology in Architecture (D.C.T.A.)

Abstract
The variation of surface properties, COLOUR AND LUMINOSITY, on a ceramic support protected by water repellent products is analysed. The samples (treated and untreated) were analysed using digital processing. Quantifiable measures for each ceramic sample were obtained using computer programs. Different shades to the reference, were observed on the surface of the ceramic pieces treated with water repellents. This variation is brought about by the kind of water repellent and the base material. The general conclusion was that all water repellents cause variations of the shade and brightness of the ceramic, and that the colour in the ceramic treated with water repellent products tends to the warmer shades because of the enhancement of the reds and the loss of blue.

Key words
Ceramic brick, polymeric materials, surface properties, colour, water repellents