Comportement des édifices en matériaux locaux sous l'effet des actions accidentelles et climatiques : vers une réhabilitation des constructions

Abstract

Many earthen buildings are in such a vulnerable situation that makes the permanent loss of this heritage only a matter of time. The lack of proper maintenance caused by economic and social changes, together with the fragility of the material itself, are the main threats of this heritage. Therefore, it is necessary to find new intervention techniques for earthen buildings. Preservation of earthen constructions is challenging because the durability capacity of this structural system is significantly instable in presence of water, as it has been demonstrated in previous floods worldwide. The objective of the present work is to investigate the possibility of stabilizing the soil with cheap, easily available and renewable local raw materials such as lime and cement. Human hair fibers, chicken feather fibers can be used to reinforce rammed earth leading to improved performances of the building material. It is also studied in this thesis, the valorization of the tuffs in the building construction as well as for use as a component in the foundation layers of road structures. The experimental work includes two parts. The first one is carried out at the University of Houston Texas (USA) using Bentonite, kaolinite, Fly ash, Crushed Bricks, Sand and Cement. The second one is conducted at the University of Chlef using tuff, cement, lime and clay from Zebabdja quarry for brick making. After the characterization of the materials, the tests performed included compaction test, unconfined compression, liquid limit, and plastic limit by using different mixtures of kaolinite and sand, Bentonite and sand, and Bentonite, kaolinite and sand. The results found show that specimens stabilized by lime showed higher failure strain than those stabilized by cement. The inclusion of the chicken feather fibers into the treated soil (clay) has improved the compressive strength of the clay three times compared to that of the untreated soil and the best performance was obtained at 2% of fiber content. The compaction curves show strong improvements in the characteristics obtained by adding cement to the tuff than with the tuff alone.