Pre-evaluation of fire-affected RC framed structure and its post-evaluation by load test after repair- A case study

摘要

An eight-storey reinforced concrete framed building was affected by fire in the fourth floor causing severe damage to columns, beams, and slabs. This paper presents an assessment of the extent of damage caused by fire by conducting non-destructive and partially destructive tests, methodology of repair and its post-evaluation through load test. Ultrasonic pulse velocity test was used to determine the extent of damage in concrete due to fire and core samples were taken from the structure to evaluate the available compressive strength. Reinforcement samples were taken from slab panels and subjected to tension test to know the residual strength and percentage elongation, and also to estimate the temperature. The damages caused to the members have been classified according to the severity of damage and degree to which they are manifested. The structural members were repaired using cement grouting and gumting with weld mesh. After the repair, the floor panels and the beams were subjected to load tests to an intensity of 1.25 times the live load. The deflection of the selected slabs and beams were measured at regular load intervals and the recovery was also obtained after 24 hours. The deflections were found to be within permissible limits and the building was restored for its functional requirements.