Electromagnetic and mechanical properties of FA-GBFS geopolymer composite used for induction heating of airport pavement

A soft magnetic layer in the airport pavement can shape magnetic field and improve the induction heating ef-ficiency. During the preparation of soft magnetic material, binder matrix material is mixed with magnetic sus-ceptible inclusions such as iron powders, resulting in the high magnetic and mechanical performances of the soft magnetic layer. Geopolymer, which shows high cohesion strength as well as little environmental impact, appears to be a promising binder candidate. The motivation of this work is to unveil the formation mechanisms of electromagnetic and mechanical properties of FA-GBFS geopolymer composite from the perspective of initial SiO2/Al2O3 molar ratio, so as to provide a theoretical basis for the design of geopolymer-based soft magnetic layer. Results show that the magnetic properties of FA-GBFS geopolymer composite are mainly generated by the Na+ movement. Both geopolymer reaction and calcium silicate hydration reaction exist within the FA-GBFS geopolymer composite, and the synergy of the two chemical reactions determines the electromagnetic and mechanical properties of the FA-GBFS geopolymer composite. Besides, the optimized FA-GBFS geopolymer composite can not only present a saturation magnetization intensity up to 25 times that of cement, but also meet the mechanical requirement of airport pavement.