ملخص الدراسة:

This research presents the results of a laboratory investigation of the flexural capacity such as strength, deflection and steel mechanical properties for both corroded and repaired corroded beams. Examination of the behavior of crack development was also examined. Fourteen small scaled reinforced concrete beams were used in the testing program. Ten out of them were tested as simply supported beams subjected to two concentrated point loads. Two out of the ten as control beams two others as corroded beams and six of them as repaired beams. The other four were used to investigate the corrosion rate and the mechanicals properties for corroded steel bars. An electrochemical system was used to achieve the corrosion level. The specimens were immersed in a 5 percent of sodium chloride solution for a period of 11 weeks. The beams were connected in parallel to +5 Volts with a capacity of 25 Amperes electric DC current generated by power supply which impressed an equal voltage on each beam to accelerate the corrosion process. Steel bars were immersed in the solution to act as a cathode and to force the steel reinforced concrete beam to act as an anode. Six corroded beams out of the fourteen were structurally repaired after been corroded. Additional longitudinal steel reinforcement bars fixed with shear connectors were added to the flexural corroded reinforcement. Three types of cementitious and resin repairing materials were used to apply a new layer instead of the crashed deteriorated beams bottom concrete cover. It was concluded that the flexural capacity of the corroded beams reduced by about 28 % compared with the control beams and showed a noted reduction in its ductility behavior during the flexural test. The flexural capacity of the repaired beams increased by about 47 % compared with the control beams. They showed good ductility behavior during the flexural test and performed as sound constructed beams regarding their flexural capacity, crack development and deflection. It also concluded that types of repairing materials used for applying a new layer to corroded beams did not affect the flexural performance of repaired beams, in spite of that it may be important to inhabit the corrosion process in the future.

توثيق المرجعي (APA)