Enhancing the usability of electronic waste fibers in high-performance self-compacting mortar incorporating corn cob ash and silica fume: Fresh and hardened properties

In the pursuit of sustainable construction materials, incorporating electronic waste (E-waste) fibers into self-compacting mortar (SCM) mixtures offers a promising avenue. This study investigates the effects of varying E-waste fiber content, ranging from 5% to 25% by volume, in combination with cement replacements such as corn cob ash and silica fume, on the properties of SCMs. A comprehensive analysis encompassing workability, mechanical properties, durability, microstructure, and chemical resistance provides insight into the potential of E-waste fibers. The inclusion of E-waste fibers, specifically at lower levels of 5% and 10%, had a beneficial effect on the workability of the SCM mixes. According to the findings of flow time tests carried out using the mini-slump and mini-V-funnel apparatus, the addition of a superplasticizer is responsible for the improved performance. Nevertheless, an increase in fiber content (15%, 20%, and 25%) necessitates a higher dosage of superplasticizer, which adversely affects the stability and cohesion of the fresh SCM mixes. The mechanical properties revealed a fascinating trend, with E-waste fibers enhancing compressive strength and splitting tensile strength at early and long-term curing ages. The mix with 5% fiber content, hereafter referred to as the E5 mix, demonstrated a compressive strength of 55.8 MPa at 91 days, indicating the positive effect of the fiber on strength. However, a higher fiber content gradually reduced these properties. The durability aspects indicated that lower fiber content in E-waste positively influenced water absorption and electrical resistivity properties. However, challenges emerged concerning chemical resistance as mass loss from exposure to sulfuric acid increased with higher E-waste fiber content. This observation indicated potential reduced resistance to chemical attack in highly fiber-reinforced SCMs. These findings provide valuable insights for optimizing SCM compositions in sustainable construction practices, considering the interplay between E-waste fibers and other cement replacement materials. Future research may focus on refining the synergy between these components to maximize their advantages effectively.