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Geopolymers are green materials with three-dimensional silicon and aluminum tetrahedral structures that can be serving as environmentally friendly construction materials and therefore have the potential to contribute to sustainable development. In this paper, the mechanism and research progress regarding the carbonation resistance, structural fire resistance, corrosion resistance, permeation properties and frost resistance of geopolymer concretes are reviewed, and the main problems with the durability of geopolymer concretes are discussed. Geopolymers possess the superb mechanic property and their compression strengths could be higher than 100 MPa. Generally, the higher the GPC strength, the better the carbonation-resistant. GPC has excellent fire resistance, due to geopolymers are acquired an inorganic skeleton which is affected by the alkali content, alkali cation, and Si/Ai ratio. There are a large number of Al-O and Si-O structures in geopolymers. Geopolymers do not react with acids at room temperature and can be used to make acid-resistant materials. Besides, GPC owning low porosity volume shows good resistance to permeability. The freezing-thawing failure mechanism of geopolymer concretes is mainly based on hydrostatic and osmotic pressure theory. GPC has poor frost resistance, and the freezing-thawing limit is less than 75 times.

A hybrid fiber‐reinforced plastic (HFRP) composite is defined as a composite material that is reinforced by two or more continuous fiber materials in the same resin matrix. This article used the hand layup method to prepare epoxy‐based flax and glass HFRP composites. Under the same fiber hybrid ratio, the interlayer and sandwich hybrid lamination methods were used for mechanical properties testing of the composite. The tensile and bending properties of the HFRP composites were obtained by tensile and three‐point bending tests, and the cross‐sectional morphology of the material was observed by a scanning electron microscopy. The thermomechanical properties of the HFRP composite were analyzed by the dynamic mechanical thermomechanical analysis (DMTA). The results showed that the effect of the different layup methods on the tensile properties of the HFRP composite material was less than the effect of the bending properties, and the bending properties showed a significant positive effect for the hybrid composites. When the glass fiber sheet was used as the core layer and the flax fiber sheet was used as the surface layer, the hybrid composites had improved bending properties, and their bending strength and flexural modulus were approximately 3.22 times and 3.81 times that of flax FRP composites, respectively. The storage modulus and glass transition temperature of the HFRP composites were higher than those of flax FRP composites as they increased by 84.1% and 8.01°C, respectively.

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