PSI - Issue 81

Serhii Drobyshynets et al. / Procedia Structural Integrity 81 (2026) 406–410

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cycle, the total deflections amounted to 1.13 mm and the residual deflections to 0.43 mm, which corresponds to an increase of 5.6% and 7.5%, respectively, compared with the fifth cycle. Prior to failure in the eleventh cycle, the total deflections increased to 5.56 mm, which is five times higher than the value recorded in the first cycle. It was established that during low-cycle testing, the upper load level slightly affects the development of deflections. It was also

found that the deflections tend toward relative stabilization. The failure patterns of the tested beams are shown in Fig. 3.

a

b

c

Fig. 3. Failure patterns of the beams: (a) B-1, (b) B-2, (c) B-3

4. Conclusions 1. It was established that the type of reinforcement significantly affects beam deflections under low-cycle loading. Reinforced concrete and reinforced concrete with rebar and steel fibers beams exhibited a similar pattern of deflection development throughout the entire loading-unloading process, indicating effective composite action of reinforcing bars and steel fibers within the concrete matrix. 2. Reinforced concrete with rebar and steel fibers beams, compared with reinforced concrete beams, exhibited slightly smaller deflections at the initial loading stages (up to 5% in the first cycle), as well as a more uniform and stable growth of deflections with an increasing number of cycles. This confirms the positive effect of dispersed reinforcement on the rigidity of elements within the service load range. 3. The failure pattern of the beams confirmed that reaching the ultimate strains of the reinforcement is the governing criterion for loss of load-bearing capacity, while the presence of steel fibers promotes a more ductile failure process and increases the energy absorption capacity of the system. References Andriichuk, O., Babich, V., Yasyuk, I., Uzhehov, S., 2017. The influence of repeated loading on the work of steel fiber concrete drainage trays and pipes on the roads. MATEC Web of Conferences 116, 02001. Andriichuk, O.,Yasiuk, I.,Uzhehov, S.,Palyvoda, O., 2021. Experimental research of strength characteristics of steel fiber reinforced concrete gutters and modeling of their work using the finite element method. Lecture Notes in Civil Engineering 100, 1 – 8. Andriichuk, O., Babich, V., Yasyuk, I., Uzhehov, S.,2018. The impact of the reinforcement percentage on the stress-strain state of bending steel fiber reinforced concrete elements. MATEC Web of Conferences 230, 02001. Babych, E.M., Andriichuk, O.V., 2017. Strength of Elements with Annular Cross Sections Made of Steel-fiber-Reinforced Concrete Under One-Time Loads. Mater Sci 52, 509 – 513. Babych, Ye.M., Andriichuk, O.V., Kysliuk, D.Ya., Savitskiy, V.V., Ninichuk, M.V., 2019. Results of experimental research of deformability and crack-resistance of two-span continuous reinforced concrete beams with combined reinforcement. IOP Conference Series: Materials Science and Engineering 708, 012043. Babich, Y, Filipchuk, S, Karavan, V., Sobczak-Piastka, J., 2019. Research of basic mechanical and deformative properties of high-strength fast-hardening concretes. AIP Conference Proceedings 2077, 020003. Babych, Y.M., Savitskiy, V.V., Andriichuk, O.V., Ninichuk, M.V., Kysliuk, D.Y., 2019. Results of experimental research of deformability and crack-resistance of two span continuous reinforced concrete beams with combined reinforcement. IOP Conference Series: Materials Science and Engineering 708(1), 012043. Blikharskyy, Y., Selejdak, J., Bobalo, T., Khmil, R., Volynets, M., 2021. Influence of the percentage of reinforcement by unstressed rebar on the deformability of pre-stressed RC beams. Production Engineering Archives 27(3), 212 – 216. Bosak, A., Matushkin, D., Dubovyk, V., Homon, S., Kulakovskyi, L., 2021. Determination of the concepts of building a solar power forecasting model. Scientific Horizons 24(10), 9-16. Chapiuk, O., Kratiuk, O., Zadorozhnikova, I., Boiarska, I., Rud, V., Boiarskyi, M., Mudryy, I., Pelekh, A., 2025. Method for determining the minimum anchorage length of reinforcement in concrete: an experimental study. Procedia Structural Integrity 72, 308-314.