COUPLING OF REINFORCEMENT IN SHOTCRETE
Keywords:
shotcrete, shotcrete-concrete, anchoring, pulling rods, coupling, tension in reinforcementAbstract
Shotcrete technology has significant advantages, in particular, the possibility of applying shotcrete to any surfaces located in any plane. Due to its high adhesive properties, shotcrete can be applied to surfaces with different characteristics, as well as be reinforced. Adhesion forces of shotcrete with various surfaces, and especially with reinforcement, will ensure the compatible operation of the structure, its bearing capacity and deformability. In Ukraine, as well as abroad, many researchers have studied the problem of bonding reinforcing bars with concrete and fiber concrete, and there is a developed corresponding methodical and calculation-normative base. In our opinion, the processes of anchoring rods in shotcrete, as well as the influence of various factors on the parameters of the rebar coupling, are insufficiently studied and require more detailed consideration.
The research program provides for evaluating the adhesion of sickle-shaped reinforcement (diameter 8 and 10 mm), the development of shear and stress in rods in shotcrete (C20/25) depending on its placement during the application of layers of shotcrete. Based on the conducted experimental data, it is planned to compare the results of anchoring samples in concrete and shotcrete.
Test samples of concrete were made by vibration in a horizontal position, and shotcrete samples were made by applying the selected composition of shotcrete to the reinforced surface. The reinforcement on the surface of the prepared formwork was arranged parallel and perpendicular. After the mass of shotcrete matured, it was cut into samples. The research involved the extraction of reinforcement rods of class A500C, earned in the center of the base of prismatic samples with dimensions of 100 × 100 × 150 (100).
The conducted experimental studies were supplemented with new data on the adhesion of reinforcement in shotcrete, and the influence of the execution technology on the development of shifts and stresses in the reinforcement rods. The analysis of the performed experimental data shows that the adhesion of reinforcement in shotcrete and normal stresses in the reinforcement were up to 8% lower than in concrete samples.
References
Babichenko V. Ya., Snisarenko V. I. The development of shotcrete technology and the need to provide it with a regulatory framework. Building constructions: coll. works of science in two books. Kyiv: SE NDIBK, 2013. Iss. 78, book 2. P. 385–390.
Babych E. M., Babych V. E., Polianovska O. E. Adhesion of sickle profile reinforcement to concrete and its anchoring in flexural reinforced concrete elements: monograph. Rivne: Volyn, 2017. 160 p.
Bandelt M. J., Billington S. L. Bond behavior of steel reinforcement in high-performance fiber-reinforced cementitious composite flexural members. Materials and Structures. 2016. Vol. 49. P. 71–86.
Bilozir V. V., Mazurak R. A. Analysis of factors influencing the adhesion of sickle-shaped reinforcement with concrete and fiber concrete. Modern technologies and calculation methods in construction. 2020. Issue. 14. P. 47–54.
Chapiuk O. Adhesion of reinforcement bars of different diameters of class A500C with concrete. Bulletin of the Ternopil National Technical University: Ser. Mechanical engineering, production automation and machining processes. 2013. No 2. P. 156–163.
DBN V.3.1-1-2002 Repair and reinforcement of supporting and enclosing building structures and foundations of industrial buildings and structures. Kyiv. State Building of Ukraine, 2003. 82 p.
Hross O.I., Poias D.V. Strength of contact seams of reinforced concrete structures. Roads and bridges: сoll. of science pr. Kyiv: DNDI, 2009. Issue 11. P. 57–64.
Mazurak A. V., Barabash V. M. Use of shotcrete in strengthening concrete and reinforced constructions. Roads and brodges: collection of scientific works. Kyiv: DerzhdorNDI, 2008. Issue 10. P. 172–176.
Mazurak A. V., Kovalyk I. V., Mykhailechko V. O., Kalitovskyi V. M. Strength of contact seams during repair or reinforcement of concrete elements. Bulletin of Lviv Polytechnic National University, No 55 «Theory and practice of construction». 2013. P. 249–254.
Wall J. S., Shrive N. G. Factors affecting bond between new and old concrete. ІCI Materials Journal. 1988. Jfe 2. P. 117–125.
