Assessment of hygrothermal and mechanical performance of alkali activated Borassus fiber reinforced earth-based bio-composite

Abstract

This investigation presents the results of a multiscale examination of the hygro-thermal and mechanical properties of designed earth-base bio-composite. The matrix and the fiber reinforcement were processed naturally to achieve eco-friendliness manufacturing technique. The bio-composite was produced using a reconstituted soil matrix and natural Borassus fruit fiber as the reinforcing phase. One-part alkaline activation of in-situ earth matrix is considered as the manufacturing process in addition to the mechanical compaction technique used to optimize the sample performance. The adhesion of the Borassus fruit fiber to the earthen matrix was evaluated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and Fourier transform infra-red (FTIR). Compressive and flexural strength testing were used to assess the mechanical properties of the bio-composite in addition to the hygric characterization or water sensibility's analysis. The thermal behavior of the bio-composite was investigated using the hot disk technique. All the characterizations were carried out on the bio-composite after 7-, 14- and 90-days curing. The Borassus natural fiber inclusion at 0.5 wt% resulted in the improvement of compressive and flexural strength due to crack propagation barrier-like feature. Water sensitivity, thermal conductivity was optimal with 0.75 wt% Borassus natural fiber content. The implications of the results are aimed to develop earth-based matrix reinforced with natural fiber produced locally from agro-waste for durable construction with low energy consumption during life-service. • Microstructural examinations were carried out to link their effect to the macrostructural performance. • Agro-waste reinforcement and soil reconstitution are used to investigate the mechanical, hygro-thermal properties of the bio-composite. • The agro-waste content on the bio-composite properties were examined. • Hygro-thermal properties of the bio-composite were resorted to inspect the water sensitivity and thermal comfort of the bio-composite.