The Influence of Fiber on the Mechanical Properties of Geopolymer Concrete: A Review

Geopolymer is widely used as a supplement to cementitious composites because of its advantages of low carbon and environmental protection, and geopolymer concrete is also broadly used in practical engineering. In recent years, geopolymer concrete has attracted increasing interest owing to its superior mechanical properties, and a series of research results have been obtained. In this paper, from the preparation of geopolymer concrete, based on the characteristics that geopolymer concrete is brittle and easy to crack, the types and basic properties of fibers to enhance the toughness of concrete are analyzed, the advantages and disadvantages of different fibers used as a material to enhance the toughness of concrete are summarized, and we review the effects of type, shape, volume rate, aspect ratio, and hybrid fiber combinations on the static mechanical properties. The results indicate that fibers have significant potential to enhance the compressive strength, splitting tensile strength, flexural strength, and fracture toughness of geopolymer concrete, and the optimal fiber volume rate seems to be related to the fiber type. Whereas the effect of aspect ratio and hybrid fiber combinations on the properties of geopolymer concrete seems to be obvious. This paper reviews the influence of fiber on the basic mechanical properties of geopolymer concrete, which provides a solid foundation to promote the further development and application of the research on the toughness of fiber-reinforced geopolymer concrete and provides recommendations for future research.