Lobodanov M. Strength and deformability of bending reinforced concrete elements with damaged concrete compressed zone under load

The dissertation is devoted to solve the problem of the influence of concret damage in the compressed zone, receiving under load, on strength and deformabilit of the bending reinforced concrete elements of rectangular section. Analysis of the results of experimental tests showed that the load-bearing capacity of reinforced concrete beams with a damaged area of compressed concrete is reduced compared to control samples. The decrease in the bearing capacity of reinforced concrete beams of the 1st series (working rebars 2Ø14A500C) in comparison with the samples that received damage without load was 22.89%. While the damage was performed under the action of load in reinforced concrete beams of the 1st series, showed a decrease in bearing capacity by 17.57… 23.61% relative to control samples. The effect of varying the width of the damage in the compressed zone of concrete on the load-bearing capacity is not significant, because it does not exceed 1%. The results of testing the samples of the 2nd series, damaged without load, showed a decrease in bearing capacity by 6.13… 16.77% compared with control samples of the same series. Damage due to the load of reinforced concrete beams of the 2nd series (with working reinforcement Ø12A500C) led to a decrease in bearing capacity by 6.14… 23.32% relative to the control. In the 2nd series of damage, the 80×30mm performance showed an increase in bearing capacity in the range of 12.8 ... 15.91% relative to reinforced concrete samples 11 with 20×30mm damage, and was recorded dependence of the applied load level at which the damage was performed. Changing the width of the damage to the compressed zone (from 20 mm to 80 mm) affects the residual load-bearing capacity of reinforced concrete beams of each series in different ways.