Soil mechanical stabilization and determination of its position in vernacular materials of hot and dry climate

Abstract

Soil has been one of the oldest and most widely building materials utilized by humans, especially in hot and dry areas. Therefore, recognizing the historical methods of stabilization and strengthening of earthen materials, which have been used in the regions with hot and dry climate of Iran, can cause the reuse of earthen materials in contemporary architecture. In the process of soil preparation for the production of vernacular materials in hot and dry climate, there is an important stage for kneading and throwing of mud, which results in relative density, porosity reduction and consequently, improved properties of earthen material. This method is known as mechanical stabilization in building engineering knowledge and, although its effect on the improvement of mech­­­anical properties of earthen materials is well-known and studied, research on the ability of kneading and throwing of mud, has not been considered. So, the present study aims to determin the position of mechanical stabilization in the structure of vernacular materials of hot and dry climate, and an overview on the types of mechanical stabilization methods and the factors affecting it, as well as the earthen materials produced in this way, is carried out. The present study is carried out in the form of an applied research, based on combinatory methods (descriptive and field studies). For this purpose, after the library studies, as well as field surveys, the process of applying mechanical stabilization on earthen materials were considered. The results of the study on mechanical stabilization in earthen materials, indicate the desired effect of kneading and throwing of mud with sufficient moisture content compared to the current method of mechanical stabilization, ie, low moisture compressed soils. Therefore, it can be concluded that the traditional architects of this climate have implicitly been aware of the correct method of mechanical stabilization and the existence of a positive relationship between this technique and mechanical properties of vernacular material of hot and dry climate. Considering the desired effect of mechanical stabilization on the improvement of mechanical properties of earthen materials, if the correct incorporation of this technique with the method of traditional earthen production materials is carried out, the earthen materials in the present age can be applied in the architecture of hot and dry climate.