Abstract: Exposure of reinforced concrete RC building to an accidental fire may result in cracking and loss in the bearing capacity of their major components like columns, beams and slabs. It is challenge for structural engineers to develop efficient rehabilitation techniques that enable RC beams to restore their structural integrity, after being exposed to intense fires for long period of time. Relatively few studies have been under taken on repair techniques for structural elements. Therefore, this study was carried out to generate experimental data on repair techniques for fire affected RC beams. A total of fourteen RC beams were cast with similar cross-sectional details, length and grade of concrete and clear cover provided to reinforcement. Fourteen beams were meant for fire exposure and the remaining one beam is used as companion beam. After the curing period of 28 days, all the 14 beams were tested initially by rebound hammer and ultrasonic pulse velocity meter. After testing the specimens individually meant for temperature exposure of 100 to 600o C with increments of 100oC each for 2 h duration and allowed to cool to room temperature. Again the specimens were tested for rebound hammer and ultrasonic pulse velocity tester after exposed to elevated temperatures. After heating, the fire affected beams were repaired with repair technique 1 and 2. Again specimens were tested for rebound hammer and ultrasonic pulse velocity tester. Thereafter, these test specimens were tested, for flexure. The percentage variations of average compressive strength by rebound hammer test and percentage variation of average pulse velocity by ultrasonic pulse velocity test have been studied. The load deflection behaviour of repair technique 1 and 2 of repaired beams have been studied and presented.
Key words: Reinforced concrete, structural integrity and rebound hammer.

| DOI: 10.17148/IARJSET.2021.8207