Strengthening of the compressed and bent reinforced concrete structures with external reinforcement systems using keyed connections

Introduction. Ensuring of the joint operation of the reinforced structure and the reinforcement structures is a key factor for successful reinforcement of structures. Traditional methods of ensuring of the joint operation are not always applicable in practice. One possible method is to create concrete keys in the reinforced structure and transfer forces from them to steel key plates fixed on the reinforcement structures (beams) or vice versa (columns). Aim. To illustrate the application of the method under consideration, we used the example of reinforcing of the monolithic reinforced concrete beams and steel columns. Materials and methods. The reinforcement was carried out using modern construction materials, including Mapei construction chemicals, and modern methods, including laser cleaning of the surface of steel structures from corrosion products. Results. It was found that the application of the method under consideration does not require unique qualifications from the performer, and the method is quite effective. The inclusion of reinforcement structures is indirectly confirmed by the results of structure monitoring, but due to the operating conditions of the structures, they have not been tested (including failure test). Conclusions. The method discussed in the article can be recommended for use in difficult conditions. However, it is necessary to conduct an experimental verification by testing the structures to failure.