August 3, 2006

Three Ways Of Using Laser In Earthen Architecture Preservation

In restoration projects ,the main concern is to maintain the main structure, aesthetic and historical features of the building .It is attempted to retain the appearance without any changes but the materials in project, used for restoration, damage to the originality of the building and it may be changed to a destructive factor in future .
It seems that the restoration in which the least external materials are used is the best restoration strategy .In this research, using laser in surface treatment of ceramics and earthen buildings is studied exclusively theoretical and we hope that by providing experimental environments, we will be able to do practical experiments.

How can we minimize the impact of destructive external factors (moisture, erosion, wind and flowing sands)?
How can we increase the mechanical hardness of the brick materials surface?
How can we prevent to the expansion of the fine cracks in the brick surface?

In Earthen Architecture, fine cracks and fatigue are among destructive factors which cause entering the contamination and moisture into the building and because of different strong factors such as freezing, lead to the destruction of the building. For preventing these factors, the surface should be protected from entering contamination or moisture .In this research, using laser as a new preservation method in ceramics and earthen buildings is studied. The advantage of this method compared with the other repairing methods is not using (or minimum usage) external materials.
Laser has been defined as scattering the light from upper levels of energy in atoms and molecules. In the state of reverse population, laser has three types of solid, liquid and gas that in this study, because of low cost, gas laser of co2 is used.
Lasers are often used as heat sources to change the surface properties of materials by phase transformation or surface alloying. Conventional laser surface treatments are now well-established methods for hardening or improving the corrosion resistance of materials. in the field of laser surface processing, Laser shock processing (LSP) is novel surface treatment, distinct from shot peeing, explosive treatment, and high power continuous laser treatment for improving the fatigue resistance of materials.

1-Changing the crystalline structure of brick surface and increase of volume and change in mechanical properties by inserting Nitrogen N2 .
2-Changing the crystalline structure of brick surface and increase of volume and change in mechanical properties.
3-Compaction of the surface layer by laser

Key Words: Laser Shock Processing, LSP, Preservation, Surface Treatment, Earthen architecture

Faraz Soleymani,
Nima Ghamarian, Metallurgy Eng.

Posted by faraz at August 3, 2006 10:57 PM