Moisture Absorption of cork-based Biosandwich Material Extracted from Quercussuber L. Plant: ANN and Fick’s Modelling

Abstract

The building sector is one of the most dynamic in terms of energy consumption, consuming about 40% of the world’s energy. This same sector is also responsible for about 1/3 of the world’s greenhouse gas emissions. In recent years, the adoption of composite materials, particularly those strengthened through the use of natural fibers is growing in all areas. This increase is the direct result of the important performances offered by these materials and that includes lightness, thermal, and acoustic insulation along with respect for the environment. This led to the integration of materials, such as bio composites or bio sandwiches, into various building structures constructions relating to civil engineering. However, numerous researches related to bio composites showed the need to explore them further particularly concerning the issue of moisture absorption as the presence of water affects the behavior of plant fibers both in terms of swelling and degradation. It is within this context that the present study focuses on modeling the water absorption behavior of bio sandwich materials having an agglomerated cork core associated with fibers extracted from the plant Quercussuber L. Fick’s law and Artificial Neural Network (ANN) are applied to model the experimental results pertaining to this absorption behavior. The experimental investigation starts by placing the original samples in tank filled with distilled water at an ambient temperature of 25°C. Mass samples are later and periodically taken on specimen with cork core having different thicknesses (5, 10, and 20 mm) as well as on laminated skin sandwiches made of short flax fibers until saturation that lasted around 25 days. The two Fick’s diffusion characteristic parameters represented by the mass gain at saturation (Mm) and the diffusion coefficient (D) were determined analytically and water absorption kinetics behavior was recorded and later compared to the curves predicted by Fick’s laws. Statistical processing of the results was carried out through the application of the analysis of variance ANOVA.

Keywords

• flax fibers
• sandwich structure
• water absorption
• fick’s law
• ann