A monolithic “unibody” construction of structural assemblies through vacuum-assisted processing of agro-waste fibrous composites

This research explored the feasibility of using vacuum-assisted infusion process (VIP) and agricultural waste - based materials to in-situ build unitary (or “monolithic”) structural components and assemblies. Mechanical properties of the natural/synthetic hybrid fiber composite materials were studied. The experimental results show that in combination with a small amount of glass fiber, the nonwoven coconut coir fiber mats can be used as structural sheathing material to provide satisfactory strength and stiffness. In addition, five “unibody” light-frame composite shear panels sheathed with the coconut coir/fiberglass material and two plywood panels were fabricated; and three composite “I”-shape beams were prototyped using the vacuum infusion process. The structural behaviors of the composite shear panels and beams were tested and compared to those of conventional plywood constructions. The results indicate that structural members constructed through VIP have satisfactory stiffness and strength and they offer better structural integrity and energy dissipation over conventional constructions. The design and construction technique outlined in this paper provides a means to in-situ construct complex-shaped structural assemblies with minimal or no joint. The experimental data showed good agreement with results calculated through classical laminate theory (CLT).