Introduction. With the growth of plastic production and the accumulation of plastic waste, recycling is becoming increasingly important. The incorporation of recycled polymers in the construction industry promotes a more rational use of natural resources and can reduce the cost of building materials. This article reviews studies examining changes in the physical and mechanical properties of concrete composites containing polypropylene (PP) and high-density polyethylene (HDPE) waste used as partial replacements for fine and coarse aggregates.

Materials and methods. A systematic analysis, generalization, and synthesis of data from open-access Russian and international sources were performed. Practical experience in the use of recycled polymers for producing concrete composites was examined to assess the effect of replacing conventional aggregates with PP and HDPE waste on the strength properties of concrete.

Results. Data on the characteristics of plastic waste, technologies for manufacturing concrete composites, and the resulting material properties were systematized. The authors conducted a comparative analysis of changes in the strength characteristics of concrete depending on the parameters of natural aggregate replacement with recycled PP and HDPE.

Conclusions. Analysis of the scientific literature on the application of plastic waste in concrete production demonstrates the significant potential of this research area. The use of recycled HDPE and PP appears particularly feasible because of their widespread availability and ease of processing. When these wastes are incorporated into concrete mixtures, material strength generally decreases with increasing waste content. However, in some cases, strength improvements compared with control specimens have been reported. Further research on the physical and mechanical properties of concrete containing combined PP and HDPE waste, as well as the determination of optimal component proportions and production technologies, remains relevant.