Mullite fiber reinforced geopolymer composite material as well as preparation method and application thereof

The invention relates to the technical field of fiber reinforced geopolymer composite materials, in particular to a mullite fiber reinforced phosphoric acid excited geopolymer composite material as well as a preparation method and application thereof. The acid-activated geopolymer composite material provided by the invention contains a mullite fiber reinforced phase structure. The mullite fibers are selected and uniformly doped into the geopolymer material, and the formed reinforced phase can significantly improve the mechanical properties of the acid-activated geopolymer material and reduce the high-temperature shrinkage rate of the acid-activated geopolymer material. Researches show that the compressive strength of the geopolymer added with 10% of mullite fiber in 7 days can reach 26.1 MPa (mean value), and the bending strength of the geopolymer in 7 days can reach 10.4 MPa; the linear shrinkage of a geopolymer sample added with 20% of fibers is as low as 3.13% after the geopolymer sample is treated at 1350