INFLUENCE OF DEFECTS OF THE WORKING REBAR ON THE BEARING CAPACITY OF THE REINFORCED CONCRETE BEAMS

Every construction is influenced by different factors during operation. As a result, there are various defects and damage of these elements, which affects their operating condition. One of such defects is the corrosion of the working rebar. Investigation of samples with corrosion is a complicated and labor-intensive process. Instead of corrosive effects, we perform controlled valves of damaged. In this way, we obtained experimental samples with a fixed value of reducing the diameter of the valve. The research of the bearing capacity of reinforced concrete beams with 13 controlled values of corrosion or damage is a topical issue. In this article, the results of experimental researches of reinforced concrete beams with a defect in the tensile rebar, which made with and without the initial loading, are presented. As a defect, one hole of diameter 5.6 mm was made at the middle of the rebar. Total eight concrete reinforced beams were tested. The samples were divided into two series: two samples of the first series and the sixth of the second. Two samples from each series were tested as controls. Four reinforced beams from the second series were tested as damaged samples. The reinforced concrete beams of the first and second series differ in diameter of the working rebar. Control samples of both series were destroyed due to the chipping of the compressed zone of concrete. Damage damages have changed the character of destruction compared with samples with equivalent reinforcement. The samples, which were damaged without initial loading, were destroyed due to the rupture of the tensile rebar. The same type of destruction is detected for the samples, which damaged at the operating level of loading. Bearing capacity of testing beams with damage without loading level and with equivalent reinforcement to damaged valves, is practically the same, the deviation is approximately 4 %. Thus, it was established that this type of damage corresponds to a decrease in the load bearing capacity of the sample, depending on the working rebar. When the damage is performed at a certain level of load, the bearing capacity increases by about 10 %. Therefore, the load level increases the residual bearing capacity of damaged specimens.

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