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.

Historic buildings carry the history of human civilisation, and their conservation and utilisation are widely valued by countries around the world. At present, the lack of qualitative and quantitative assessment and evaluation methods for the preservation status and attachment value of historic buildings poses a challenge to the smooth implementation of the conservation and utilisation of historic buildings. The development of a set of system standards for the assessment and evaluation of historic buildings is an urgent task for the conservation and utilisation of historic buildings. This paper proposes a set of comprehensive mapping assessment and evaluation system for historical buildings through the analysis and sorting out of the current situation of preserving historical buildings and their development lineage, architectural style, building type, society and art. Finally, based on the above mapping evaluation system, 20 historical buildings are graded according to the requirements of historical building classification, and according to the different levels. Corresponding conservation measures are proposed and different planning schemes are formulated to better utilise the historical, scientific, cultural and economic values of historical buildings.

Expanded polystyrene concrete (EPSC) is increasingly utilized in buildings as a green building material. To investigate the effect of high-tenacity polypropylene (HTPP) fibers on the carbonation resistance (CR) of EPSC, five groups of EPSC specimens with HTPP fiber volume fractions of 0%, 0.6%, 0.9%, 1.2%, and 1.5% were prepared. Rapid carbonation tests were conducted to measure the carbonation depth (CD) and uniaxial compression strength (UCS) of the specimens at different carbonation ages (3, 7, 14, and 28 days). The CD and UCS of the specimens were calculated and analyzed. The results indicated that the HTPP fibers dramatically improved the CR of EPSC, with a decrease in the CD of up to 29.5% at 28 days. A model for predicting the CD of EPSC was developed. The model for the strength after carbonation also showed good agreement with the experimental results. Scanning electron microscopy (SEM) was used to examine the microstructure of the HTPP-reinforced EPSC, while the mechanism of HTPP fibers to enhance the CR of EPSC was elucidated. The findings of this study provide valuable insights for the application of EPSC as a structural material.