The influence of random loading on the strength of concrete and reinforced concrete structures

Authors

DOI:

https://doi.org/10.32347/2410-2547.2024.113.139-148

Keywords:

loads, random loads, residual deformations, cracks, reinforced concrete

Abstract

It is known that practically all structures during operation are subjected to small but repetitive loads, the magnitude of which in some cases may exceed operational levels and have a random nature. Such influences include wind pulsations, accidents, seismic, technological, temperature-humidity loads. Existing methods for calculating structures do not take into account the peculiarities of concrete behavior under real conditions subject to random loading. However, such loading leads to an increase in residual deformations, an increase in the number of cracks, disruption of the bond between concrete and reinforcement, and can lead to the exhaustion of bearing capacity and premature failure.

Among various structural elements of buildings and structures, columns are most often subjected to technological and emergency influences, which determined the purpose of this research.

The determination of the scope of experimental research was carried out taking into account active experimentation. When developing the plan of a full factorial experiment, the following variable quantities were set: number of cycles n; load level η; relative eccentricity value . The research results showed that repeated loading for the investigated specimens led to an increase in bearing capacity compared to a one-time load by 18-30% depending on the magnitude of the eccentricity and the load level. To describe such loading, methods of random variables and processes were used. In this work, this approach is implemented based on the Monte Carlo method. The technology of applying this method is as follows: by reproducing a set of pseudo-random numbers, a selective realization of random loading is modeled according to a given distribution law as a function of the number of cycles. After testing concrete prisms according to a specified program, the realization of the parameters of the stress-strain state of concrete was obtained.

By conducting statistical processing of the obtained realizations, probabilistic characteristics of the investigated parameters were calculated. Statistical processing of test results allowed obtaining approximating equations for building dependencies  on each load cycle. To confirm the possibility of using the test results of prisms in studying the stress-strain state of off-center compressed elements, their bearing capacity was determined in the work.

Determining the bearing capacity by this methodology was agreed with the values of the bearing capacity obtained using regression equations based on a full factorial experiment.

This approach to the study of concrete can be used to determine the strength and reliability of building structures operating under various types of external influences (loads) using the apparatus of the theory of random variables and processes.

Author Biographies

Tetiana Chyrva, Kyiv National University of Construction and Architecture

Candidate of Technical Sciences, Associate Professor, Associate Professor of the Department of Architectural Structures

Vira Koliakova, Kyiv National University of Construction and Architecture

Candidate of Technical Sciences, Associate Professor, Associate Professor of the Department of Reinforced Concrete and Stone Structures

Viacheslav Martynov, Kyiv National University of Construction and Architecture

Doctor of Technical Sciences, Professor, Professor of the Department of Architectural Structures

Volodymyr Chyrva, LLC "Prydniprovya"

Candidate of Technical Sciences, Associate Professor, Director of Prydniprovya LLC

References

Babych Ye.M., Krus Yu.O. Betonni ta zalizobetonni elementy v umovakh malotsyklovykh navantazhen: Monohrafiia. (Concrete and reinforced concrete elements under short-cycle loads: Monograph). - Rivne: Vyd-vo RDTU, 1999.- 119 s.

Babych, V. Ye. Osoblyvosti roboty nerozriznykh zalizobetonnykh balok pry povtornykh navantazhenniakh [Tekst] (Features of the operation of continuous reinforced concrete beams under repeated loads [Text]) .- Budivelni konstruktsii : zb. nauk. prats. – Kyiv : NDIBK, 2003. –Vyp. 58. – S. 8-13.

Chyrva T.L., Cherkaska N.A., Chyrva V.N. Metodyka vyznachennia vplyvu vypadkovykh navantazhen na mitsnist zalizobetonnykh stysnutykh elementiv.(The method of determining the influence of random loads on the strength of reinforced concrete compressed elements).- KTU ,Visnyk 8, 2005 .-s.37-49.

Chyrva T.L., Chyrva V.N., Cherkaska N.A. Utochnennia kharakteru ta osoblyvostei vplyvu vypadkovykh navantazhen na zalizobetonni konstruktsii (Clarification of the nature and features of the impact of random loads on reinforced concrete structures).- «Stalyi rozvytok hirnycho-metalurhiinoi promyslovosti – 2007- Kryvyi Rih, 2007.- s.59-63.

Barashykov A.Ia., Koliakova V.M. Vplyv istorii navantazhennia na tryvalu mitsnist betonu pry dvovisnomu stysku (Influence of load history on long-term strength of concrete under biaxial compression).- Budivelni konstruktsii. Mizhvidomchyi naukovo-tekhnichnyi zbirnyk "Naukovo-tekhnichni problemy suchasnoho zalizobetonu. NDIBK – 2003. – Vyp. 59. – S. 103-108.

Koliakova V.M. Vplyv istorii navantazhennia na tryvalu mitsnist betonu pry dvovisnomu stysku (The influence of load history on the long-term strength of concrete under biaxial compression).- Zb. nauk.statei "Problemy teoriia i praktyka budivnytstva". PDTU – 1997. –S. 247-25.

Karpiuk V.M., Somina Yu.A., Kostiuk A.I., Maistrenko O.F. Osoblyvosti napruzheno-deformovanoho stanu i rozrakhunku zalizobetonnykh konstruktsii za dii tsyklichnoho navantazhennia vysokykh rivniv: monohrafiia (Features of the stress-strain state and calculation of reinforced concrete structures under the action of cyclic loading of high levels: monograph). – Odesa: ODABA, 2018. - 233 s.8.

Karpiuk, V. M. Albu K. I., Danylenko D. S., Somina Yu. A.. Vplyv tsyklichnoho znakozminnoho navantazhennia na mitsnist, treshchinostiikist ta deformatyvnist zalizobetonnykh elementiv, shcho zghynaiutsia (Effect of cyclic alternating load on the strength, crack resistance and deformability of reinforced concrete elements that bend). - Mosty ta tuneli: teoriia, doslidzhennia, praktyka, 2014, № 6. s.56-68.

Karpiuk V.M., Karpiuk V.M., Syomina, Yu.A. Bearing capacity of common and damaged cfrp-strengthened r. C. beams subject to high-level low-cycle loading // Materials Science Forum Том 968 MSF, pp. 185 – 199.-2019 International Conference on Actual Problems of Engineering Mechanics, APEM 2019 Odessa. Код 231069 10.4028/www.scientific.net/MSF.968.185

Kartashov M. V. Imovirnist, protsesy, statystyka. (Probability, processes, statistics.).- Kyiv : VPTs Kyivskyi universytet, 2007. - 504 s.

Aslani F. Stress-strain model for concrete under cyclic loading / F. Aslani, R. Jowkarmeimandi // Magazine of Concrete Research. – Wollongong, Australia, 2012. – Vol. 64, Issue 8. – Pp. 673-685.

Dorofeev V. Their capacity steel cross-section eccentrically shrink or stretch beams / V. Dorofeev, V. Karpyuk, N. Petrov // Materials of 18 Conference «Theoretical Foundations of Civil Engineering », Polish – Ukrainian – Lithuanian Transactions– Warsaw, September, 2010. – P. 345-352.

Chyrva Т.L, Chyrva V.N. The research of strength of eccentric compression reinforced concrete elements at random loading. Proceedings of the repair, 2007, 17th International Symposium, Brno, 2007 “Sanace-2007”.-p.379-384

Kupfer, H., Hilsdorf, H. K., & Rusch, H. (1969, August). Behavior of concrete under biaxial stresses. In Journal proceedings (Vol. 66, No. 8, pp. 656-666).

Shamsoon Fareed. (2018). Behavior of reinforced concrete slabs under accidental impacts [Data set]. ISEC PRESS. https://doi.org/10.12755/ISEC.RES.2018.73

Nazar Oukaili, M. K. (2019). Flexural ductility of structural concrete members subjected to limited cycles of repeated loading [Data set]. ISEC PRESS. https://doi.org/10.12755/ISEC.RES.2019.81

Smorkalov D, Zhuravskyi O and Delyavskyy M. Experi-mental and theoretical studies of single and double-layerslabs supported on four sides. In:AIP conf proc 2019,vol. 2077, paper no. 020052. College Park: AIP Publish-ing LLC

Ahmed S. Eisa, Louay A. Aboul-Nour, Asmaa El-Ghamry, Martina Zeleňáková and Dušan Katunský Flexural behavior of two-layer reinforced concrete slab with hollow cores Advances in Mechanical Engineering 2024, Vol. 16(2) 1–20 https://doi.org/10.1177/16878132231224940

Published

2024-11-29

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