Following previous studies by the authors on laser surface treatment of cementitious materials and natural stone to produce a new generation of decorative panels for use as architectural building materials, this paper describes the effect of laser treatment on the surface characteristics, humidity absorption and release characteristics and on the mechanical behaviour of cement mortar containing zeolite as the aggregate. The results obtained indicate that,
The roughness of the glassy ceramic layer produced by laser irradiation is strongly dependent on the power density of the laser beam on the mortar surface. Lower power density used with lower processing speed produces a smoother and more lustrous ceramic layer and is therefore desirable from the point of view of visual appearance. High power densities result in the formation of undesirable “knife edges”.
Methods of correcting the distortion were investigated. Increasing the thickness of the panel reduces distortion to acceptable levels, but at the expense of greater weight. It is also possible to make use of the inherent property of dimensional change of mortar due to hydration or dehydration, to pre-bend or post-bend the panel so as to minimize the distortion caused by laser heating.
By mixing small quantities of metallic oxides, it is possible to produce, on laser irradiation, surface ceramic layers of various colours. In addition, the laser treated zeolite mortar has excellent humidity absorption and release characteristics, which makes it an ideal material for use in buildings as decorative interior panelling.