ANALYSIS OF INFLUENCE OF MAIN TYPES OF DEFECTS AND DAMAGE ON THE BEARING CAPASITY OF REINFORCED CONCRETE ELEMENTS

In nowadays economic trends, there is a need in changes in the usage of buildings and structures. This usually leads to the changes loading and character of the loadings type on the building structures, with the subsequent need to assess the technical condition and the replacement or enhancement of certain elements. Also, objects, which need the reconstruction in order to be reequipped or changed it functionality, that have designs which were used under the influence of an aggressive environment or other factors which were not taken into account. This increases the difficulty of the rating of the technical condition of individual constructions and further reconstruction. An important place in the possibility of reconstruction of buildings and structures is determining to the residual bearing capacity of the elements. This is
especially true for reinforced concrete elements widely used on the territory of Ukraine. An important aspect of determining the residual ability of bending reinforced concrete elements is the study of the effect of defects and damage on the changes in strength and deformation ability of the element. As reinforced concrete is a complex composite material, the determining of impact and predicting the effects on it of various types of defects and damage is a rather difficult task. This mainly concerns the combination of various defects and damage, which increases the variability of the various internal and external factors in the calculation and further formation of the methodology of determining the impact. Therefore, this issue is not completely solved and requires further researching. In the article, the researches of influence of defects and damages on residual bearing ability of damaged reinforced concrete elements with accentuation on bending reinforced concrete beams are analyzed. The main types of defects of reinforced concrete beams are the corrosion of the reinforcement, the reduced cross-sectional area, defects obtained in the manufacture, transportation and operation of structures With consideration of the action of various types of defects and damage and their certain combinations, which lead to changes in the characteristics of the strength and deformability of the element, and the possible change in the operation of the element.

1 Konstruktsii budynkiv i sporud. Betonni ta zalizobetonni konstruktsii. Osnovni polozhennia [Construction of houses and buildings. Concrete and reinforced concrete structures. The main provisions of the]. (2011). DBN V.2.6-98:2009 from 1 th July 2011. Kiev: Building norms of Ukraine [in Ukraine].

2. RILEM TECHNICAL COMMITTEES: Damage classification of concrete structures. The state of the art report of RILEM Technical Committee 104-DCC activity, Materials and Structures (1991). Matg’riaux et Constructions. pp. 24, 253–259.

3. Klymenko E. V. Oreshkovich M. (2013). Do pytannia vyvchennia roboty stysnutykh poshkodzhenykh zalizobetonnykh elementiv kruhloho pererizu [On the study of the work of compressed damaged reinforced concrete elements of round section]. Bulletin of the National University
“Lviv Polytechnic”. The theory and practice of construction. No. 755. P. 173–178.

4. Malganov A. I., Plevkov V. S., Polischuk A. I. (1990). Vostanovlenye y usylenye stroytelnыkh konstruktsyi avaryinыkh y
rekonstruyruemыkh zdanyi: atlas skhem y chertezhei [Restoration and strengthening of building structures of emergency and reconstructed buildings: atlas of schemes and drawings] Volume. Unt. 456 pp.

5. Voskobinik O. P. (2010). Typolohichne porivniannia defektiv ta poshkodzhen zalizobetonnykh, metalevykh ta stalezalizobetonnykh balkovykh konstruktsii [Typological comparison of defects and damages of reinforced concrete, metal and steel reinforced concrete structures]. Bulletin of the National University “Lviv Polytechnic”. The theory and practice of construction. No. 662. P. 97–103.

6. Klymenko E. V. (2012) Vlyianye povrezhdennosty na prochnost y deformatyvnost yzghybaemыkh zhelezobetonnыkh эlementov [Influence of damage on the strength and deformability of bendable reinforced concrete elements]. Bulletin of the Odessa State Academy of Civil Engineering and Architecture. Exp. 51. P. 175–180.

7. Normatyvni dokumenty z pytan obstezhen, pasportyzatsii, bezpechnoi ta nadiinoi ekspluatatsii vyrobnychykh budivel i sporud [Normative documents on issues of inspection, certification, safe and reliable operation of industrial buildings and structures]. (1997). Effective from 1997-11-27. State. committee of the building, archit. and the Housing Policy of Ukraine, Gosnadzoradzorohrantruda of Ukraine. 145 p.

8. Tekhnycheskaia dyahnostyka. Termynы y opredelenyia [Technical diagnostics. Terms and definitions].(1989). GOST 20911-89. Effective from 01/01/1991. GK USSR on product quality management and standards. 132 p.

9. Stepova O. V. (2011) Metodyka rozrakhunku vtraty ploshchi pererizu pry korozii armatury v normalnii trishchyni balkovykh zalizobetonnykh konstruktsii [Method of calculation of sectional area loss due to corrosion of reinforcement in normal cracking of beam reinforced concrete constructions]. Resource-saving materials, constructions, buildings and structures: sciences Ave. Vol. 21. P. 346–352.

10. Pavlikov A. M., Boyko O. V. (2011) Vyznachennia kuta nakhylu neitralnoi linii v pererizakh kosozihnutykh zalizobetonnykh elementiv z urakhuvanniam neliniinykh vlastyvostei betonu na osnovi diahram yoho stanu [Determination of the inclination angle of the neutral line in the cross sections of oblique concrete concrete elements, taking into account the nonlinear properties of concrete on the basis of diagrams of its state]. Resource-saving materials, constructions, buildings and structures: Sb. sciences Ave. Vol. 21. S. 264–269.

11. Klymenko E. V. Cherneva E. S. Korol N. D. Ismael Aerez M. M. Antonyshina I. V. (2014) Ostatochnaia nesushchaia sposobnost povrezhdennыkh zhelezobetonnыkh balok tavrovoho profylia [Residual bearing capacity of damaged reinforced concrete beams of the tread profile] Bulletin of the Odessa State Academy of Civil Engineering and Architecture. Vol. 54. P. 159–163.

12. Klymenko E. V., Cherneva O. S., Dovgan O. D. Aries Mohammed Ismael. (2013) Vplyv faktoriv poshkodzhenykh tavrovykh balok na velychynu yikh ruinivnoho navantazhennia [Influence of the factors of damaged taurian beams on the magnitude of their destructive load]. Intercollegiate collection “SCIENTIFIC NOTES”. No. 43. P. 94–97.

13. Voznesensky V. A. (1981). Statycheskye metodы planyrovanyia эksperymenta v tekhnyko-эkonomycheskykh yssledovanyiakh [Static methods of experiment planning in technical and economic research]. 2nd ed. M: Finance and Statistics. 215 p.

14. Verb I. I., Luchko Y. Y. Kovchyk S. E. (2002). Do pytannia korozii betonu i zalizobetonu ta yikh zakhystu [To the issue of corrosion of concrete and reinforced concrete and their protection]. Bulletin of the Lviv Polytechnic National University. The theory and practice of construction. No. 441. P. 34–39

15. Khmil R. E. Vashkevych R. V. Blicharsky Z. Ya. (2009). Napruzheno-deformovanyi stan zalizobetonnykh balok z mistsevymy koroziinymy poshkodzhenniamy [Strained-deformed state of reinforced concrete beams damaged by aggressive environment]. Bulletin of the National University “Lviv Polytechnic” The theory and practice of construction No. 655. P. 278–285.

16. Betonnyye i zhelezobetonnyye konstruktsii [Concrete and reinforced concrete structures]. (1986). SNiP 2.03.01-84* Repealed from 1 th June 2011. M.: State standard [in Russian].

17. Bliharsky Z. Ya., Khmil R. E. Vashkevich R. V. Bliharsky Ya. Z. (2011). Napruzheno-deformovanyi stan zalizobetonnykh balok z mistsevymy koroziinymy poshkodzhenniamy [The stress-strain state of reinforced concrete beams with local corrosion damage]. Bulletin of the National University “Lviv Polytechnic”. Theory and practice of construction. No. 697. P. 36–41.

18. Zhuravskaya N. E. (2014) Do pytannia bioposhkodzhennia betonu ta zalizobetonu [To the issue of biological damage to concrete and reinforced concrete]. Resource-saving materials, structures, buildings and structures. Vol. 28. P. 180–186.

19. Petrov O. M. (2015). Trishchynoutvorennia ta kharakter ruinuvannia zalizobetonnykh elementiv pry zghyni z kruchenniam [Cracking and the nature of the destruction of reinforced concrete elements with bending with torsion]. Building constructions. Vol. 82. P. 507–518.

20. Voskobinik, O. P., Kitayev O. O., Makarenko Ya. V., Bugaenko Ye. S. (2011). Eksperymentalni doslidzhennia zalizobetonnykh balok z defektamy ta
poshkodzhenniamy, yaki vyklykaiut kosyi zghyn [Experimental investigations of reinforced concrete beams with defects and damages that cause slanting bends]. Collection of sciences. works (branch machine-
building, construction). Vip. 1 (29). pp. 87–92