Investigating the Potential of Doum Fibers in enhancing Geopolymer Composite Derived from Mining Waste

The construction industry is currently focusing its scientific research efforts towards improving the sustainability of manufactured materials. This shift necessitates the adoption of environmentally friendly raw materials and innovative technologies to reduce energy consumption and natural resource depletion. Geopolymers are increasingly recognized as a viable eco-friendly alternative to conventional building materials due to their outstanding physical and mechanical properties. This study investigates the influence of different fiber loadings on the physical and mechanical properties of geopolymer composites made from mining waste as the base material and palm Doum fibers (PDFs). The manufacturing process involves activating mining waste with a concentrated sodium hydroxide solution to form a homogenous paste, which is then blended with PDFs. The resulting mixture is poured into molds and allowed to cure for 28 days . Following this, the formulated composites were tested to assess their physical, mechanical, and morphological properties, including the modulus of rupture (MOR), the modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS), and SEM microscopy.

The findings indicated that geopolymer composites reinforced with palm Doum fibers exhibited higher mechanical properties compared to the neat matrix. Optimal results were achieved with a fiber content of 2%, resulting in maximum values of 13.93 MPa for the MOR and 2.30 GPa for the MOE. However, the incorporation of PDFs into the mining waste matrix has led to increased levels of both WA and TS due to the higher quantity of hemicellulose, facilitating water infiltration inside the composite and the subsequent expansion of fibers. Furthermore, analyzing the morphological characteristics of interfacial failure highlights a clearly defined boundary between the matrix and fibers, offering a significant understanding into exceptional mechanical and physical attributes.

In conclusion, these materials offer a promising solution to the growing demand for eco-friendly construction materials.