PSI - Issue 81

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ScienceDirect

Procedia Structural Integrity 81 (2026) 509–513

© 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of DMDP 2025 organizers Keywords: reinforced concrete; flexural element; stress-strain state; load-bearing capacity; crack; deformability; deflection. 1. Introduction Concrete and reinforced concrete materials are widely used in the construction of buildings and structures for various purposes (Ahmad et al. (2022); Sobczak-Piastka et al. (2019); Dvorkin et al. (2021); Chapiuk et al. (2025); Andriichuk et al. (2021); Dovbenko et al. (2024)). Structural elements made of concrete and reinforced concrete are often subjected to different types of loading (Filipchuk et al. (2024); Bosak et al. (2021); Drobyshynets et al. (2024)). Reinforced concrete beams are among the most Abstract Experimental studies of rectangular reinforced concrete beams with mixed reinforcement subjected to a single short-term loading were carried out. The tests revealed the characteristic performance features of such flexural elements. At the initial loading stage, prior to crack formation (η < 0.5), insignificant development of concrete and tensile reinforcement strains was observed. At this stage, the concrete in both the compressed and tensile zones, together with the working reinforcement, exhibited joint deformation behaviour. The appearance of normal cracks at stress levels of η > 0.5 caused a redistribution of internal forces from the cracked tensile concrete zone to the working reinforcement, resulting in an intensive increase in strains, beam deflections, and a reduction in the height of the compressed concrete zone. Within the stress range of 0.5 ≤ η ≤ 0.7, a slowed growth of concrete strains and a further decrease in the height of the compressed zone were observed. At stress levels of η > 0.7, an accelerated development of concrete and tensile reinforcement strains, as well as beam deflections, occurred, accompanied by a sharp reduction in the height of the compressed concrete zone. This behaviour indicates the transition of the structure to the failure stage and the onset of reinforcement yielding. The failure of the beams was gradual in nature. At the moment of failure, the stress in the extreme compressed concrete fibre exceeded its prism compressive strength, while no slippage of the prestressed reinforcement was observed during the tests. VIII International Conference “In - service Damage of Materials: Diagnostics and Prediction“ (DMDP 2025) Results of Experimental Studies of Flexural Reinforced Concrete Elements with Mixed Reinforcement Yuriy Panchuk a , Ivan Stetsko b , Bohdan Karavan a , Vitalii V. Kovalchuk c , Andriy Pelekh c , Oleg Parneta c , Ihor Mudryy c, *, Vladyslav Sysiak d a National University of Water and Environmental Engineering, Soborna 11, 33000 Rivne, Ukraine b Uzhhorod National University, 14 University Str., 88000 Uzhgorod, Ukraine c Lviv Polytechnic National University, S. Bandery 12, 79013, Lviv, Ukraine d Ternopil Ivan Puluj National Technical University, Ruska 56, 46001 Ternopil, Ukraine

* Corresponding author. Tel.: +38-096-202-09-07; fax: +0-000-000-0000 . E-mail address: qwert_2024@ukr.net

2452-3216 © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of DMDP 2025 organizers 10.1016/j.prostr.2026.03.097