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Against the background of people’s increasing awareness of personal safety and property safety, the flame retardancy (FR) of materials has increasingly become the focus of attention in the field of construction engineering. A variety of materials have been developed in research and production in this field. Polymers have many advantages, such as their light weight, low water absorption, high flexibility, good chemical corrosion resistance, high specific strength, high specific modulus and low thermal conductivity, and are often applied to the field of construction engineering. However, the FR of unmodified polymer is not ideal, and new methods to make it more flame retardant are needed to enhance the FR. This article primarily introduces the flame-retardant mechanism of fire retardancy. It summarizes the preparation of polymer flame-retardant materials by adding different flame-retardant agents, and the application and research progress related to polymer flame-retardant materials in construction engineering.

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The investigation of gas transport in microfractures of tight/shale reservoirs can provide potential applications in predicting shale gas production rates. In this paper, analytical expressions for flow rate and apparent permeability are derived based on the fractal theory and the superposition of convection and molecular diffusion transfer. The proposed model relates the flow rate and apparent permeability to the microstructural parameters of tight/shale reservoirs, gas properties, the ambient pressure as well as temperature. The model predictions from the present model are compared with existing experimental data sets and are found to be consistent with existing experimental measurements. The effects of microstructural parameters of tight/shale reservoirs on apparent permeability are also investigated. The results show that apparent permeability increases with temperature, the pore area fractal dimension, the porosity as well as the maximum microfracture width and decreases with the tortuosity fractal dimension and the mean pressure.