Mechanical Properties of a New Lightweight Soil-Based Construction Material Incorporating Invasive <i>Rugulopteryx okamurae</i> Seaweed

ABSTRACT Rugulopteryx okamurae (hereinafter, R. okamurae) is an invasive species that causes severe environmental and socioeconomic impacts in southern Spain, thereby necessitating waste management solutions. The accumulation of this material on beaches in this region is a major concern for local authorities. Its use in manufacturing new alternative production goods that provide economic value for this material is an optimal solution for the management of this waste. On the other hand, the use of natural vegetal fibers as new additives constitutes an attractive ecological approach to reduce the environmental footprint of the industry in this sector. This article presents a proposal for the production of a lightweight clay material that incorporates R. okamurae as a natural fiber that focuses on the feasibility of integrating significant quantities of this specific invasive waste R. okamurae. The results from simple compression tests of samples of this new material are presented. Samples are produced with three different R. okamurae proportions (20 %, 25 %, and 30 % by weight) and subjected to simple compression tests. The results quantify the mechanical response and show that samples with 20–30 % alga content achieve compressive strengths between approximately 1.0 and 2.4 MPa. Notably, increasing the alga content within the tested range leads to higher peak compressive stress, although a greater strain is required in order to reach said peak. The results illustrate the potential feasibility of the use of this composite material in construction. The possibility of using a high content of fibers and therefore reusing large amounts of vegetal waste is an attractive contribution when compared with similar previous proposals from the literature.