Effect of a Composite Activator on Comprehensive Performance of Alkali-Activated Foam Concrete

This study investigates the synergistic mechanism between composite activators (NaOH and Na₂SiO₃ blend) and the microstructure-macroperformance relationship of foam concrete, focusing on the influence of different activator dosages on foam concrete stability, compressive strength, and drying shrinkage behavior. Experimental results indicate that excessively high activator dosages impair foam concrete stability, reduce compressive strength, and accelerate drying shrinkage. However, an appropriate amount of composite activator effectively improves the stability of freshly mixed foam concrete, significantly reducing settlement rates. During the hardening stage, it optimizes pore size distribution, promotes the formation of denser hydration products, and enhances the mechanical properties of the pore framework, thereby synergistically improving the mechanical performance of foam concrete.