Research on the Influence of the Percentage of Longitudinal and Fiber Reinforcement on the Strength of Normal Sections of Rubber Concrete Beams of a T-Section

This article presents the results of testing the strength of samples of rubcon and fiber rubcon beams of a T-section, with a different percentage of longitudinal reinforcement. Rubber concrete (or abbreviated as rubcon) is a highly effective composite polymer concrete based on liquid rubber, which has favorable physical and mechanical characteristics, as well as almost universal chemical resistance to corrosive media. Bars of class A500C were used as longitudinal reinforcement; as transverse-Bp500, with a diameter of 5 mm and a step of 50 mm. Fiber reinforcement is represented by steel fibers with a diameter of 0.3 mm and a length of 30 mm (that is, a ratio of diameter to fiber length of 1/100) arranged randomly throughout the entire volume of the experimental beams. The section of the beams is assigned with the requirements of CR 63.13330.2012 “Concrete and reinforced concrete structures”: length - 1400 mm; web height - 95 mm; web width - 60 mm; flange height - 25 mm; flange width - 240 mm; the number and diameter of the longitudinal rebars - 0; 1Ø8; 1Ø10; 2Ø10; 2 Ø12 mm; which corresponds to the percentage of longitudinal reinforcement - 0; 0.80; 1.25;2.50; 3.60%. The technique of experimental studies of bending elements of mixed reinforcement is described. The results of testing beams for pure bending are presented. It is established that with an increase in the percentage of longitudinal reinforcement, the value of the destructive bending moment increases in a linear relationship. When adding fiber reinforcement, an increase in the values of the destructive bending moment is observed up to 10%.