Anchoring of a working rebar made with a plug connection

It is proposed to use smooth steel pipes in the plug connection, which will be embedded parts in a monolithic foundation, into which the working rebars of the prefabricated column will subsequently arrive, glued onto a fast-setting liquid-type mixture. Thus, this plug joint design is the object of research. However, there is a question of the joint work of the smooth surface of the pipe and fine-grained bulk concrete after solidification, which is used as an adhesive solution for gluing reinforcing rebars. Methods. An experimental study of the anchoring of the working rebars as part of the plug connection has been carried out. The experiment involves applying a tensile load to a sample consisting of a reinforcing rebar glued onto a fast-hardening liquid-type mixture in a steel pipe. The load increased stepwise until the sample was destroyed. The method of processing the results is photogrammetric photography. Results. The relative deformations of the reinforcing rebar were determined by photogrammetric imaging. The high degree of adhesion of steel to a fast-hardening liquid-type mixture under the action of a tensile load was confirmed. The experimental sample collapsed on the base metal of the rebar outside the pipe. The equal strength of the reinforcement adhesive joint is ensured. Based on the experiment, concrete was found to be punctured at the points of relative elongation and narrowing of the reinforcing rebar after exceeding the design stresses, therefore, a process of reducing the anchoring of the working reinforcement was observed, which subsequently may cause a loss of strength of the plug connection of the prefabricated column and the monolithic foundation.