Study on Improving the Interface between Recycled Glass Fiber and Cementitious Material by Combined Treatment of Various Silane Coupling Agents

Amidst the relentless surge in demand for fiberglass products in recent years, a concomitant rise in product remnants and obsolete fiberglass materials has presented a pressing challenge of resource wastage. To address this dilemma and scrutinize the resource utilization potential of recycled fiberglass, the present study explores the utilization of waste fiberglass materials. Through physical comminution, two distinct forms of recycled fiberglass, namely powder and fibers, were isolated and characterized. The study further investigated the impact of varying dosages of these recycled fiberglass components on the fluidity and resilience of mortar, establishing five distinct dosage tiers. To enhance the compatibility and performance of the recycled glass fibers, four silane coupling agents (KH550/560, KH550/570, KH560/570, KH792/560, KH792/570) were employed for surface modification. At the optimal dosage, a comprehensive analysis was conducted to evaluate the effects of different coupling agents on the mechanical properties of recycled glass fiber-reinforced cementitious materials. The findings revealed that the addition of fiberglass powder significantly enhances the fluidity of the mortar, whereas an increase in fiber content adversely affects its flowability. Notably, the direct incorporation of unmodified recycled glass fibers did not yield significant improvements in the flexural and compressive strengths of the specimens. In light of the substantial variations observed in the flexural and compressive strengths, a maximum addition of 2% recycled glass fibers in reinforced cement mortar products is proposed. The enhanced material performance, particularly with the addition of KH550/570 silane coupling agent, validates the efficacy of incorporating modified recycled glass fibers. This study not only sheds light on the potential utilization of waste fiberglass materials in high-value applications but also paves the way for future research in the area of sustainable resource utilization and waste management.