# Strengthening Polymer Concrete with Carbon and Basalt Fibres
## 1 Introduction  
Modern composite materials, including polymer concrete and fibre concrete, are gaining popularity in various industries due to their high-performance characteristics, which are in many ways comparable to traditional metals, such as cast iron and aluminium alloys. The use of reinforced polymer concrete provides significant economic benefits. In some cases, replacing metal materials with polymer concrete reduces the cost of both the material and production processes. This is especially relevant in conditions that require resistance to aggressive environment, high loads and extreme temperatures. Polymer concretes demonstrate high resistance to aggressive influences. A key factor that stimulates the growth of their popularity is reinforcement with various types of fibre. In recent decades, the scientific community has been actively exploring the potential of reinforcing the concretes with fibres to increase their strength and durability. In particular, studies on the efficiency of reinforcing the polymer concretes with carbon and basalt fibre have shown promising results. This opens prospects for using reinforced polymer concretes in mechanical engineering and construction technologies. Further research can lead to significant innovations in the production of polymer concretes and the expansion of their application beyond the construction industry. This will provide new opportunities for mechanical engineering and other industries, contributing to the creation of lighter, stronger and more cost-effective components. Such achievements will contribute to the sustainable development of industry and economy, ensuring the growth of technological efficiency and the reduction of operating costs. Scientific and applied research in the field of reinforcing polymer concretes with carbon and basalt fibres has high scientific and practical significance. These works can contribute significantly to the development of new technologies and methods of using polymer concretes, which will ultimately have a positive influence on various industries. A sufficiently large number of works are devoted to the study of the influence of various reinforcing admixtures on the performance properties of concrete [1; 2; 3; 4]. One of the promising materials used for fillers is basalt fibres and carbon fibres [5; 6]. New studies show that in some cases these fibres, used as fillers, can replace the reinforcement with metal rods and provide a comparable increase in strength. The authors of [7] investigated in their work the reinforcement with different types of materials. They used reinforcing rods, made of steel, basalt and glass. The results of their work showed that steel rods allowed obtaining a maximum strength gain of 57%. However, when basalt rods were used, the strength gain was 32%, and when glass rods were used, it was 27%. In [8], studying the concrete reinforcement with basalt fibre and glass fibre additives in the concrete mixture, positive results were also obtained. The compressive and bending strengths of concrete increased during compression and bending tests. The maximum increase in compressive strength was achieved when adding basalt fibre, which was 25%. Basalt fibres are used to enhance the mechanical properties of concrete when gravel is used as a filler [9]. The addition of basalt fibres 12 mm long in the amount of 0.4% increased its compressive strength by more than 44%. In this work, concrete with a gravel filler was used. Basalt fibre is often used as a filler in combination with other fillers. The combination of basalt fibre with cellulose granules allowed the authors of [10] to increase the compressive strength of concrete by more than 20%. Reference [11] is devoted to determining the optimum amount of basalt fibre to be added. Basalt fibre was introduced into the concrete composition in the amount of 0, 0.1, 0.3 and 0.5%. The studies showed that the best strength properties were obtained using concrete containing 0.5% of basalt fibre.