Mechanical and thermal characterization of compact blocks made of clayey earth with wood ashes addition

¹ Laboratory of Testing and Research on Wood Material (LERMAB), Faculty of Science & Technology / University of Lorraine –Bd. des Aiguillettes B.P. 70239 F-54506 Vandoeuvre-lès-Nancy cedex, France.
² Laboratory of Applied Energetics and Mechanics (LEMA), Polytechnic School of Abomey-Calavi / University of Abomey-Calavi, 01 BP. 2009 Cotonou (Benin).

^* Corresponding author: dysenan@yahoo.fr

Abstract

The objective of this study is to evaluate the influence of wood ashes on the mechanical and thermal characteristics of the clayey earth-ashes compound (CEAC) compressed blocks. Variable mass percentages of 0% to 60% of wood ashes were incorporated to clayey earth stabilized with 10% of cement. The physical characteristics of the clayey earth were determined according to the protocols of the french association of normalization. The manufactured blocks were subjected to mechanical tests: simple compression and tensile by bending. The thermal conductivity was then appreciated by the method of the hot strip. The blocks made with a mixture of “90% clayey earth” and “10% cement”, usually used in construction in Benin, served as a reference material. From the results obtained, it appears that the clayey earth used is a soil A2ts: fine clayed sand in a very dry state. The results of the mechanical and thermal tests show that for an addition of wood ashes between 10% and 20% by weight, the performances of the blocks are significantly improved. The CEAC blocks formulated from 80% of the mixture “90% of clayey earth and 10% of cement” and 20% of wood ashes can be used as building materials.