Performance study of foam concrete prepared by the synergistic utilization of agricultural waste and coal gangue based on double orthogonal experiments

The utilization of coal gangue (CG) as a substitute for cement in building materials offers an effective solution to mitigate resource wastage and environmental pollution caused by CG accumulation while also reducing carbon dioxide (CO2) emissions. This paper employs orthogonal experiments to examine the effects of CG content, water/binder ratio (w/b), and foam content on the mechanical, thermal insulation, and durability properties of coal gangue foam concrete (CGFC). Additionally, we explored the properties of CGFC incorporating organic agricultural waste. Microscopic analyses focused on phase composition, morphology, and pore structure, providing crucial insights into how these experimental factors affect FC properties. The results indicate that foam content significantly impacts the mechanical properties of the concrete, while the w/b ratio is critical for its thermal insulation and water absorption capabilities. Introducing agricultural waste fibers notably enhances thermal insulation and freeze-thaw durability. Specifically, adding 1 % of 15 mm processed straw fibers (PST) optimally improved CGFC performance by creating a stronger bond with the hydration products. Preparing FC using inorganic coal gangue and organic solid waste is essential for effective waste management and the development of energy-efficient insulation applications in the construction sector.