: 12-17
Lviv Polytechnic National University
Lviv Polytechnic National University, Department of building construction and bridges
Lviv Polytechnic National University, Department of building construction and bridges

Every construction is influenced by different factors during operation. As a result, there are various defects and damage of these elements, which affects their operating condition. One of such defects is the corrosion of the working rebar. Investigation of samples with corrosion is a complicated and labor-intensive process. Instead of corrosive effects, we perform controlled valves of damaged. In this way, we obtained experimental samples with a fixed value of reducing the diameter of the valve. The research of the bearing capacity of reinforced concrete beams with 13 controlled values of corrosion or damage is a topical issue. In this article, the results of experimental researches of reinforced concrete beams with a defect in the tensile rebar, which made with and without the initial loading, are presented. As a defect, one hole of diameter 5.6 mm was made at the middle of the rebar. Total eight concrete reinforced beams were tested. The samples were divided into two series: two samples of the first series and the sixth of the second. Two samples from each series were tested as controls. Four reinforced beams from the second series were tested as damaged samples. The reinforced concrete beams of the first and second series differ in diameter of the working rebar. Control samples of both series were destroyed due to the chipping of the compressed zone of concrete. Damage damages have changed the character of destruction compared with samples with equivalent reinforcement. The samples, which were damaged without initial loading, were destroyed due to the rupture of the tensile rebar. The same type of destruction is detected for the samples, which damaged at the operating level of loading. Bearing capacity of testing beams with damage without loading level and with equivalent reinforcement to damaged valves, is practically the same, the deviation is approximately 4 %. Thus, it was established that this type of damage corresponds to a decrease in the load bearing capacity of the sample, depending on the working rebar. When the damage is performed at a certain level of load, the bearing capacity increases by about 10 %. Therefore, the load level increases the residual bearing capacity of damaged specimens.

1. Voskobiynyk O. Kitayev P.. O., Makarenko Ya. V., Buhayenko Ye. S., (2011). Eksperymental’ni
doslidzhennya zalizobetonnykh balok z defektamy ta poshkodzhennyamy yaki vyklykayut’ kosyy zhyn
[Experimental investigations of reinforced concrete beams with defects and damages that cause skew
bends] Zbirnyk naukovykh prats’ (haluzeve mashynobuduvannya, budivnytstvo). Vyp.1 (29). P. 87–92 [in

2. Blikharskyi Z. Ya. Khmil R. Ye., Vashkevych, R. V., Struk R. F. (2009). Teoretychni osnovy
vyznachennia vplyvu korozii na nesuchu zdatnist ta prohnozuvannia zalyshkovoho resursu zalizobetonnykh
konstruktsii [Theoretical basis for determining the impact of corrosion on bearing capacity and
forecasting the residual resource of reinforced concrete structures] Teoriia i praktyka budivnytstva.
No. 655. P. 13–18. [in Ukrainian].

3. Klymenko Ye. V. Chernieva O. S., Ismaiel A. M. (2013). Kharakter
ruinuvannia poshkodzhenykh tavrovykh balok. [The character of the destruction of damaged t-profile
beams] Teoriia i praktyka budivnytstva. Vyp. 755. P. 179–183. [in Ukrainian].

4. Cairns J. Zhao Z. (1993).
Behaviour of concrete beams with exposed reinforcement. Proceedings of the institution of civil engineers:
structures and bridges. Vol. 99, Issue 2. P. 141–154.

5. Prokat armaturnyy dlya zalizobetonnykh
konstruktsiy. Zahal’ni tekhnichni umovy. [Reinforcement hire for reinforced concrete constructions.
General specifications] (2006). DSTU 3760:2006 Kiev: Building norms of Ukraine [in Ukrainian].

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

7. Тurchin, B. R., Bliharskii, Z. Z., Vegera, P. І. & Shnal Т. М., (2017). Metodyka doslidzhen zalizobetonnykh
balok z poshkodzhenniamy otrymanymy za dii navantazhennia [Research methodology of reinforced beams
with damages under the action of a load]. Her. of Lviv Polytechnic National University. No. 877. P. 213–218
[in Ukrainian].

8. Betonni ta zalizobetonni konstruktsiyi z vazhkoho betonu). [Concrete and reinforced
concrete construction from heavy concrete] (2011) DBN V.2.6-98:2009. – [chynnyy vid 2011-06-01]. – K.:
Minrehionbud Ukrayiny. – 118 s. (Natsional’nyy standart Ukrayiny). [in Ukrainian].