RESEARCH METODOLOGY OF REINFORCED COCRETE BEAMS WITH DAMAGE OBTAINED UNDER LOADING

The research of reinforced concrete beams, in which there is some damage or defects are scare. This is especially applies to studies in which defects arise under the influence of the load, which is due to the complexity of such studies. This article describes a method for performing damage to stretched rebar in bending reinforced concrete elements under load. There were eight samples tested: four specimens tested as controls and four – with injuries. Control samples with a stretched rebar of 16 and 20 mm in diameter are reinforced. Damaged beams with rebar 20 mm in diameter are reinforced. Damage was carried out by drilling the hole diameters 5.6 mm in the stretched armature. The remaining area of the tensile rebar with the hole corresponds to the cross-sectional area of the reinforcement Ø16. There were simulated pointing damage of stretched reinforcement. As a result, the type of beam’s destruction was changed. Exhaustion of the bearing capacity occurs abruptly, with the breakdown of the beam into two parts. The convergence of the results of the carrying capacity of the twin samples showed a deviation of the results in the range of 3–13%.

1. Blikharskyy Z. Ya., Khmil R. Ye., Vashkevysh R. V. [The strength of reinforced concrete beams by the simultaneous action of corrosive environment and external load] Diahnostyka, dovhovichnist’ ta rekonstruktsiya mostiv i budivel’nykh konstruktsiy: Zb. nauk. prats’ [Diagnostics, durability and reconstruction of bridges and building constructions: Collection of scientific works]- Issue 3 – Lviv, 2001. – P. 23–29 (in Ukranian) 2. Mitchel A. Experimental investigation of the relation between damage at the concrete-steel interface and initiation of reinforcement corrosion in plain and fibre reinforced concrete / A. Mitchel, A.O. S. Solgaard, B. J. Pease, M. R. Geiker, H. Stang, J. F. Olesen // Corrosion Science. – 2013. – Vol.77. – P. 308–321. 3. Voskobiynyk O. P. Eksperymental’ni doslidzhennya trubobetonnykh elementiv z lokal’nymy poshkodzhennyamy truby-obolonky / O. P. Voskobiynyk, A. V. Hasenko, I. O. Parkhomenko // Resursoekonomni materialy, konstruktsiyi, budivli ta sporudy. – 2013. – Vyp. 25. – S. 688–695. 4. Ismail M. Compressive strength loss and reinforcement degradations of reinforced concrete structures due long-term exposure / M. Ismail, B. Muhammad, M. E. Ismail // Construction and building materials. – 2010. – Vol. 24. – P. 898–902. 5. Prokat armaturnyy dlya zalizobetonnykh konstruktsiy. Zahal’ni tekhnichni umovy: DSTU 3760:2006 [chynnyy vid
2006-12-11]. – K.: Instytut chornoyi metalurhiyi NAN Ukrayiny, 2006. – 28 s. 6. Konstruktsiyi budynkiv i sporud. Betonni ta zalizobetonni konstruktsiyi. Osnovni polozhennya: DBN V.2.6-98:2009. – [Chynnyy vid 2011-06-01]. – K.: Minrehionbud Ukrayiny, 2011. – 84 s. 7. Vyroby betonni ta zalizobetonni zbirni. Metody vyprobovuvan’ navantazhuvannyam. Pravyla otsinky mitsnosti, zhorstkosti ta trishchynostiykosti.: DSTU B V.2.6-7-95. – [chynnyy vid 2009-12-22]. – K.: Ukrarkhinformbud Ukrayiny, 1997. – 42 s. 8. Betonni ta zalizobetonni konstruktsiyi z vazhkoho betonu: DSTU B.V.2.6-156:2010. – [chynnyy vid 2011-06-01]. – K.: Minrehionbud Ukrayiny, 2011. – 118 s.