69439 AlfaBuild AlfaBuild 2658-5553 5 10.57728/ALF.37.5 Impact of fiber usage, high heat, and fire resistance on the mechanical properties of reactive powder concrete (RPC) Impact of fiber usage, high heat, and fire resistance on the mechanical properties of reactive powder concrete (RPC) 0000-0001-5939-3257 Nasimi Shahin shahin.nasimi@yahoo.com 0000-0002-4590-8552 Ehsani Armin arminehsani97@gmail.com 0000-0003-2272-7473 Shambina Svetlana Lvovna shambina-sl@rudn.ru Peoples' Friendship University of Russia Moscow, Russia 01 01 2026 37 1 37 3705 3705

The object of research is the composition, processing methods, and mechanical behavior of Reactive Powder Concrete (RPC), highlighting its superior durability, impermeability, and resistance to environmental degradation. Reactive Powder Concrete (RPC) is an advanced high-performance construction material developed to overcome the limitations of conventional concrete, such as low strength, poor durability, and susceptibility to chloride and sulfate attacks. RPC achieves exceptional mechanical properties with compressive strengths ranging from 170–800 MPa and flexural strengths up to 250 times that of ordinary concrete through ultra-dense particle packing, elimination of coarse aggregates, and the incorporation of steel fibers. Methods. The mechanical properties and processing techniques of powdered concrete are compared with the characteristics of different kinds of concrete currently in use. This study emphasizes RPC's revolutionary potential in contemporary building by combining research on mix designs, curing regimes, and fiber reinforcement. It addresses robustness in harsh environments as well as sustainability (by utilizing industrial byproducts). Results. Key findings indicate that heat treatment (90°C–250°C) and pre-setting pressure significantly enhance compressive strength, while steel fibers improve flexural toughness and ductility. Additionally, RPC exhibits remarkable thermal stability, with minimal weight loss and retained strength at high temperatures (up to 800°C), making it suitable for extreme environments. Comparative analyses with ordinary and high-performance concrete demonstrate RPC's advantages, including reduced porosity (2–6%), enhanced resistance to chloride penetration, and superior performance under fire exposure. However, optimal fiber reinforcement and curing conditions are critical to mitigating brittleness and ensuring structural reliability.

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