Thermal and mechanical characterization of earth bricks with local Olive pomace (Eastern Morocco) for ecological building materials.

Aboubakr El Hammouti1^{1}, Salaheddine Channouf1^{1}, Mouatassim Charai1^{1}, Ahmed Mezrhab1^{1}, Mustapha Karkri2^{2}
^{\star} :
1^{1} Mechanics and Energy Laboratory, Mohammed First University, 60000 Oujda, Morocco
2^{2} Univ Paris Est Creteil, CERTES, F-94010 Creteil, France
Mots clés : Low carbon building materials; Bio-based walls; Sustainable building; Thermal comfort; Time lag.
Résumé :

The objective of this work is to evaluate the effect of olive pomace on the thermomechanical performance of earth bricks. Olive pomace (OP) was added to the soil with different weight percentages of 0, 10, 20, 30 and 40%. The techniques consisted in identifying these raw materials from a physico-chemical point of view by using standardized laboratory tests. Firstly, raw materials’ geotechnical, mineralogical, chemical and microstructural characteristics were identified. Afterward, the thermal and mechanical properties of the produced Olive pomace-Earth were investigated by the hot disk method and by uniaxial compressive strength tests. The particle size distribution showed a clay fraction of 45% for the soil. The Atterberg limits show a moderate plasticity for this soil. The X-ray diffraction analysis (XRD) of the studied soil shows that it is composed of several minerals (Kaolinite, Illite, Quartz, Calcite and Goethite). Thermogravimetric analysis (TGA) showed a weight loss of 21% and 72% respectively for soil and olive pomace in a temperature range of 0-900^{\circ}C. The microstructure analysis of the soil and OP designed for the present work clearly showed the porous nature of the soil and OP structure. Experiments reveal that the strength of bricks decreases with increasing olive pomace content. The addition of 40% by weight of Olive pomace can improve the thermal insulation and thermal capacity of earth bricks by 54.7% and 38.6% respectively compared to the reference brick (0% olive pomace). Laboratory tests were followed by ANSYS - Fluent CFD (3D) analysis to evaluate the effectiveness of a hybrid biosourced wall in which a layer of Olive pomace-Earth is incorporated into a double hollow brick wall. Numerical results show that a 9-hour time lag was achieved with a 90 mm biosourced soil layer thickness. The results of the present study are applicable for designing more effective passive buildings in Morocco.

Work In Progress