Performance and predictive modeling of surface carbonized plant fiber reinforced alkali-activated self-insulating mortar

Incorporating stalk fibers into alkali-activated cement faces challenges: alkaline exposure leaches sugars, while their smooth, low-energy surfaces weaken interfacial bonding. To address these issues, this study focuses on the surface carbonization of stalk fibers. The microstructural characteristics of surface-carbonized stalk were systematically investigated through multiple characterization methodologies. This research thoroughly examines the effects of carbonization temperature and duration on both mechanical properties and thermal transmission characteristics of alkali-activated cement-based composites, while conducting comparative analyses of different surface modification strategies for performance enhancement in stalk-reinforced systems. Experimental findings demonstrate that surface carbonization under standard curing conditions outperforms NaOH immersion treatment, with the resultant mortar exhibiting impressive mechanical properties surpassing those of untreated stalk composites. Notably, this composite material simultaneously achieves enhanced thermal insulation performance, manifesting a thermal conductivity coefficient of 0.2373 W/m² K. Furthermore, a machine learning framework was developed to model the relationship between modified stalk microstructure and composite mechanical properties, enabling accurate prediction of material performance.