STRENGTHENING OF REINFORCED CONCRETE BEAMS WITH AN EXTERNAL BAR-ROLL SYSTEM

Abstract

In the area of making reinforced concrete bending elements, the use of external strengthening systems, including steel rods and levers, is one of the directions for increasing rigidity, cracking strength and bearing capacity of beam constructions. They can be used to build and enhance the spans of buildings and structures.

The study presents the design of a system for strengthening reinforced concrete beams that provides adjustable longitudinal compression at the expense of the energy of external load and fuller use of strength properties of materials. The specific feature of the work of this structure is the possibility of unloading the upper compressed fiber of the beam through creating tensile force by external strengthening bars on the beam.

This structure of reinforced beams was made and experimentally investigated. The strengthening system included external steel reinforcement in the form of two flexible bars and guide elements, located symmetrically on the lateral surface at the ends of the beam. The class of concrete of experimental beams was C35 / 45. A-240C was accepted as the class of the working bars.

In the course of experimental studies of the proposed reinforcing system, which includes external flexible steel bars and guiding parts for creating regulated compression, was determined that the system allowed unloading the upper compressed fiber of the beam through the tensile force of external strengthening bars on the beam. Along with a 4.42-time increase in strength compared with the conventional reference samples, it became possible to significantly reduce deformability.