Formulation of rice-straw-based composite materials

The objective of this study is to contribute to the development and enhancement of a plant-based construction material with a limited environmental impact and acceptable energy performance. To achieve this, we manufactured a composite material (Straw + Coating) by applying the coating on the two opposite faces of the straw bale. To assess the reliability of the new material, several tests were carried out to evaluate thermal comfort, such as thermal diffusivity, moisture conductivity, and acoustic conductivity. The results obtained show that the moisture level does not vary and remains constant due to the presence of a NaCl solution that controls humidity. The straw bale coated with clay regulates indoor temperature in a climatic environment subject to temperature variations, thus providing high thermal inertia. The acoustic insulation value R, ranging from 45 to 53.1 dB in the device containing the material, shows that this material is a good acoustic insulator. Straw bales are currently recognized as an insulation material and as a support for coatings, and a methodological framework has been established regarding their characterization and implementation for these uses. Based on the assumption of a “sandwich” wall behavior in which the "straw/coating" interface plays a key role, experimental and theoretical challenges have been highlighted, and research directions to overcome them have been presented.