Performance optimization of hybrid nano-engineered geopolymer binders-based ultra-high-performance concrete

Abstract

Ultra-high-performance and sustainable construction materials have given the thrust to the development of geopolymer technology. This work presents a nano-engineered geopolymer binder incorporating hybrid nano-reinforcements of nano-silica and graphene oxide at optimized ultrasonication and mechanical milling for improved dispersion and prevention of agglomeration. The resulting specimen exhibits a compressive strength exceeding 120 MPa at 24 h and a water absorption below 3 %. A microwave-assisted novel curing method accelerates geopolymerization, achieving this strength in less than 1 h and a reduction of the curing duration by 70 %. Further employing doped CNTs for structural health sensing has even greater potential, creating a self-sensing system with a gauge factor of over 25. Synchrotron XRD analysis supplies information about phase evolution, thus ensuring a crystallinity index greater than 50 %. Molecular dynamics simulations predict robust interactions with bond energies beyond 320 KJ/mol, whereas kinetic modeling optimizes reaction rates of up to 80 % polymerization within 8 h. Ballistic Impact testing shows over 50 percent enhancement in impact resistance, proving to be very robust under a severe loading condition. The overall picture created by inter alia superior mechanical properties, durability, self-sensing ability, and environmental benefits (20 % energy saving) should be considered as a paradigm shift for constructions with high performance and sustainability, stretching its applications to aerospace and defenses.