The use of fly ash in compositions as a substitute for a part of cement is economically favorable and ecologically feasible in connection with large accumulations of waste at the enterprises of the energy sector. In addition, the technology of cement production provides high-temperature treatment of mineral substances in kilns with significant emissions of carbon dioxide. One of the most effective directions of the utilization of fly ash is their use in concrete composites. The use of this material will provide the required temperature and humidity conditions in residential premises, solve the problem of “cold bridges” in structures, minimize heat losses of the structure, and increase the energy efficiency of buildings in general. At the same time, polystyrene concrete, due to its structural structure and the presence of thermally conductive concrete, has limited opportunities for thermal and physical–mechanical properties. To improve the operational properties of polystyrene concrete, it is proposed to use composite binders, including fly ash from the thermal power station of Astana. The main aim of this study is to develop compositions of polystyrene concrete with reduced thermal conductivity and improved physical and mechanical properties. The objectives of this study include the determination of characteristics of fly ash from Astana, formulation of polystyrene concrete mixtures with different proportions of fly ash, and evaluation of their thermal conductivity properties. These tasks are in line with the objectives of the ISO 50001 standard to improve energy efficiency and reduce environmental impact. The results showed that the addition of fly ash from Astana to polystyrene concrete leads to a marked reduction in thermal conductivity, contributing to improved energy efficiency of the building envelope. Optimal results were achieved by using 15% of Astana fly ash as an additive in polystyrene concrete, which led to a significant reduction in thermal conductivity of 51.47%. This reduction is in line with improving the energy efficiency of building materials, especially in cold climates.

Due to the constant increase in prices for energy resources, as well as the reduction in non-renewable resources in most developed countries of the world, the energy consumption standards of buildings are constantly decreasing, and the requirements for the level of thermal insulation of building envelopes are increasing. The increasing requirements in the level of thermal insulation of enclosing structures make the issues of improving and developing new materials and products become more urgent. Polystyrene concrete has good high-thermal and sound-absorbing properties. This serves as a means of reducing costs, improving thermal insulation, reducing the dead load (weight) on the building and outside, among many other advantages. However, concrete made with polystyrene foam as a substitute for large aggregates has insufficient strength, due to the fact that the cement has low adhesion to the polystyrene foam. Based on the research of scientists and authors on the possibility of using industrial waste, it was assumed that the addition of fly ash to the composition would strengthen the matrix and the degree of compression of the polymers by the cement matrix as a result of the presence of nanoparticles in the fly ash and their positive effect on the structure and properties of the composition. The aim of the study was to develop a heat-insulating polystyrene concrete based on a binder using fly ash and to investigate its physical and technical properties. The properties of fly ash have been studied for the purpose of safe use in mixtures to increase strength properties and improve adhesion to polymers. The involvement of industrial waste from the ashes of coal from Kazakhstani deposits will contribute to the ecological improvement of the environment of the megacities of Kazakhstan. The effect obtained from the optimal combination of the characteristics for a building material is the improved physical and mechanical properties of heat-insulating materials.

The need for stronger and more sustainable road infrastructure has stimulated research into innovative materials, including micro- and nano-additives, to improve the performance of asphalt and bitumen. This paper aims to summarize the advances in the application of these additives with a focus on improving mechanical, thermal, and environmental properties. The study provides a detailed review of traditional micro-additives such as elastomers and resins, as well as advanced nanomaterials including nano silica, nano clay, and carbon nanoparticles. Methods include analyzing experimental data from recent studies on bitumen modification with biopolymeric materials such as polylactic acid (PLA), which show an increase in molecular weight, softening point, and ductility. The main results show that the use of nano additives improves the durability of the road surface, increases its resistance to cracking, and increases the service life of the material under different climatic conditions. For example, roads modified with nano silica showed a 20-30% improvement in tensile strength and a 15% reduction in deformation. In addition, PLA bitumen modification increased the softening point by 10°C and improved the overall elasticity by 25%. These results emphasize the potential of micro- and nano-additives to create more durable, environmentally friendly, high-performance road materials.