Microstructure, Physical and Mechanical Properties of Adobes Stabilized with Rice Husks

ABSTRACT

The main objective of this study was to manufacture resistant, durable adobes having low thermal conductivity. For this purpose, a moderately plastic clayey soil from Korsimoro (Burkina Faso) was used to manufacture adobes reinforced with up to 1 wt.% of rice husks. The chemical and microstructural characteristics of the rice husks were evaluated, as were the physical, mechanical and microstructural characteristics of the adobes that were manufactured. The incorporation of rice husks in the clayey matrix increased the compressive strength of adobes and decreased their thermal conductivity. From a durability point of view, the addition of rice husks in adobes decreases the capillary absorption and improves the resistance to water erosion, due to the good adhesion of rice husks with the clayey matrix. According to standards related to building materials, adobes manufactured with at most 0.4 wt.% are suitable for the construction of resistant and durable dwellings that provide acceptable thermal comfort.

KEYWORDS:

• Adobe
• Burkina Faso
• clayey soil
• microstructure
• physical and mechanical properties
• rice husks
• thermal comfort

Research highlights

Friction between rice husks and clay molecules creates hydrogen bonds.

Rice husks in clayey matrix significantly reduce water absorption.

Rice husk additions to a clayey matrix improve mechanical strength of adobes.

Rice husk additions to a clayey matrix decrease thermal conductivity of adobes.

Stabilization by rice husks improves adobe water resistance.

Acknowledgments

The authors are grateful to Mrs Kalsibiri Kaboré and Ali Sana of the “Laboratoire National du Bâtiment et des Travaux Publics” for their help in implementing geotechnical and mechanical tests.

Disclosure statement

No potential conflict of interest was reported by the author(s).