Mechanical Characterization And Water Resistance Of Raw Earth Materials Made According To Malagasy Traditional Technique

Abstract

This study aims to contribute to a more responsible world, by stimulating the applications of natural building materials and the enhancement of the prestige of the Malagasy traditional building technique, more respectful of the environment. To this end, preliminary investigations were carried out to formulate the tested samples and to study the preparation processes of the earthen pastes. Three different lateritic soils were studied and stabilized with cow dung and rice straw. The results show that the soils used are rich in SiO 2 , Al 2 O 3 and Fe 2 O 3 . Introducing cow dung and rice straw with fermentation improves sample characteristics. Consequently, the sample density increases from 1728 to 1913 Kg/m 3 . It also increases the dry and wet compressive strengths of our samples. From the 2nd week of the paste maturation time, the dry compressive strength increases from 0.64 MPa to 1.2 MPa and at the 24th week, it is 9 times higher than that of the beginning of the tests (5.4 to 6.5 MPa). Regarding water resistance, the results show that from the 4th week of the maturation time, the samples withstand more than 24 hours of immersion in water and this resistance increases until the 24th week, becoming comparable to that of the Malagasy ancestral walls aged more than 100 years, which is equivalent to 7 days.