An Experimental Study on the Use of Fonio Straw and Shea Butter Residue for Improving the Thermophysical and Mechanical Properties of Compressed Earth Blocks

Abstract

The efficient use of building materials is one of the responses to increasing urbanization and building energy consumption. Soil as a building material has been used for several thousand years due to its availability and its usual properties improving and stabilization techniques used. Thus, fonio straws and shea butter residues are incorporated into tow soil matrix. The objective of this study is to develop a construction eco-material by recycling agricultural and biopolymer by-products in compressed earth blocks (CEB) stabilization and analyze these by-products' influence on CEB usual properties. To do this, compressed stabilized earth blocks (CSEB) composed of clay and varying proportion (3% to 10%) of fonio straw and shea butter residue incorporated were subjected to thermophysical, flexural, compressive, and durability tests. The results obtained show that the addition of fonio straw and shea butter residues as stabilizers improves compressed stabilized earth blocks thermophysical and mechanical performance and durability. Two different clay materials were studied. Indeed, for these CEB incorporating 3% fonio straw and 3%-10% shea butter residue, the average compressive strength and three-point bending strength values after 28 days old are respectively 3.478 MPa and 1.062 MPa. In terms of CSEB thermal properties, the average thermal conductivity is 0.549 W/m•K with 3% fonio straw and from 0.667 to 0.798 W/m. K is with 3%-10% shea butter residue and the average thermal diffusivity is 1.665.10 −7 m 2 /s with 3% FF and 2.24.10 −7 m 2 /s with 3.055.10 −7 m 2 /s with 3%-10% shea butter residue, while the average specific heat mass is between 1.

Improving the Building Energy Efficiency and Thermal Comfort through the Design of Walls in Compressed Earth Blocks of Agricultural and Biopolymer Residues Masonry: A Recent Study

“…The period considered for this study is the month of April, which is the hottest month in the dry tropical climate zone. This study is completely numerical and we have established a conceptual framework for a descriptive study of our working methodology based on [24]. Fig.…”

Improving the Building Energy Efficiency and Thermal Comfort through the Design of Walls in Compressed Earth Blocks of Agricultural and Biopolymer Residues Masonry

“…The period considered for this study is the month of April, which is the hottest month in the dry tropical climate zone. This study is completely numerical and we have established a conceptual framework for a descriptive study of our working methodology based on [19]. Fig.…”

“…These are local construction materials consisting of well define mixture of clay and agricultural cakes and bio-polymer and whose thermophysical and mechanical properties are characterized by [19]. This study will investigate the influence of these composite materials on the habitat thermal behaviour and compare them with cement block and cut laterite blocks (BLT) walls.…”

“…The comparative study approach was chosen to evaluate the thermal and energy performance of the building constructed with walls in CSEB formulated by [19] at the Laboratory of Construction Materials of Liege University in comparison to other common construction materials.…”

“… the walls in Compressed earth blocks stabilized with fonio straw (CSEB-A13FF or CSEB-A23FF) and coated by composite shea butter cake and earth material (CEM-A13RL formulated by [19] offer good average interior and operating temperatures;  the number of discomfort hours and the energy requirements for air conditioning is reduced;  the choice of the type of envelope construction materials is very decisive in the search of the thermal comfort achievement;…”