Page 64 - UL_Report On_Part 1

55 IITGN-UL/Façade
Timeline of events:
Event 1: Time 18:39:30: (-8.87 min)
Data acquisition is started and all thermocouples show ambient room temperatures.
Event 2: Time: 18:40:43: (-7.65 min)
Ignition of fire through remotely controlled electrical switch is initiated. However, this fails to ignite the source except for giving out some smoke.
Temperatures are still at ambient levels.
Event 3: Time: 18:48:22: (0 min): Ignition
Fire is ignited manually through a waste paper basket. No smoke obscuration is observed at any of the three floor levels.
Event 4: Time: 18:49:00: (0.63 min)
Fire is transmitted from sofa to curtains. Polyester curtains did not show visible flames but melted due to heat of surrounding fire. Maximum temperature
observed at ground floor façade level is about 218°C and average façade temperature at that level is about 29°C. Glass façade temperature at level 2 and 3
are around ambient levels.
Event 5: Time: 18:51:00: (2.63 min)
Ground floor video camera stops functioning. Smoke obscuration has increased at first floor level whereas at second floor level it is not yet observed.
Flames, as observed from outside, begin to reach the ceiling. ACP sheets begin to shrink due to heat. Maximum temperature observed at ground floor
façade level is about 275°C whereas at levels 2 and 3 it is around 45.8°C and 28.5°C, respectively.
Event 6: Time: 18:54:00: (5.63 min)
Heavy smoke obscuration is observed at first floor level and camera at first floor level stops functioning. Maximum façade temperature at ground floor
level is around 250°C. Temperatures have become constant at around 250°C for an interval of about 10 minutes as fire was not propagating within the
compartment. Wooden crib placed near the ignition source has not ignited yet.
Roof thermocouples TC # 22, 23, 30 and 31 show temperatures of around 250°C whereas temperature at base are around 50°C. Maximum thermocouple tree
temperature T4 is around 265°C. Temperatures at first and second floor level are around 30°C.
56 IITGN-UL/Façade
Event 7: Time: 19:04:50: (16.46 min)
One ACP sheet of ground floor façade fails enhancing the ventilation conditions within the compartment. Wooden crib placed in the middle of the
compartment begins to burn. Maximum temperature at ground floor façade level is around 400°C and at first floor level is about 105°C. ACP panels opened
up due to fire and the inner polyethylene core was exposed to fire and charred, as found in post-fire investigations.
Aluminium sheets
Charred
polyethylene core
Image 15: ACP showing charred polyethylene core sandwiched between aluminium sheets
Event 8: Time: 19:12:52: (24.5 min)
Another ACP sheet adjacent to the earlier one falls and further enhances ventilation within the compartment. Maximum exposed temperature at ground
level observed through IR camera is around 610°C and at first floor level is around 115°C. Temperatures reach close to melting point of aluminium and post
fire observations confirmed melting of cladding framework at certain locations.
Event 9: Time: 19:13:00: (24.63 min)
Major portion of fire protection provided to the structural beams and slab has failed at ground floor level exposing the beams and deck slab to direct heat.
Temperatures are around 600°C at ground floor level. This is a peculiar observation underlining the importance of workmanship. During fixing of cement
boards to the beams, distance kept between two successive SDS bolts was about 20” (compared to 8” in Test 1), which led to the early failure of cement
boards.