Physical and mechanical characterization of sun-dried bricks. A case history: the galeb of Kebili

Abstract

The galeb of Kebili is a sun-dried brick belonging to the construction tradition of the homonymous “oasis city” of southern Tunisia, obtained by mixing water, fired gypsum-rich Sahara sand and palm wood ash. In recent years, great efforts have been made to enhance the features of these construction materials while preserving the traditional production techniques. In order to evaluate possible improvements in the brick’s physical and mechanical properties, both different firing techniques of raw materials and various ash content in the composition, have been considered. Experimental results showed that modifying the traditional method of combustion by firing the sand at a controlled temperature (160 °C) in a standard oven, allows to obtain a galeb brick with improved mechanical and physical properties. Moreover, keeping the traditional method of combustion, mechanical and physical properties may be optimized by adding a controlled amount of raw ash (about 5 %) in the galeb bricks composition.