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103 IITGN-UL/Façade 104 IITGN-UL/Façade
Four full-scale fire tests were conducted to study different façade materials FOLLOWING MAJOR OBSERVATIONS
and fire spread mechanisms typically seen in buildings that utilize façade
systems. First three tests were designed to study external spread of fire
Part IV (leap-frog effect), where fire breaks out of one compartment and travels WERE MADE DURING THE FOUR TESTS:
CONCLUSIONS vertically through façade material (such a mechanism was responsible for
the rapid fire spread in the recent Grenfell building fire at London). Fourth
test was designed to study internal spread of fire due to failure of fire stop
& FUTURE material. • It is better to use standard rated material compared to locally available unrated materials. This was qualitatively proved when comparing Test
1 and Test 2 where the extent of damage was significant in Test 2 compared to Test 1. Test 2 utilized unrated materials while Test 1 utilized
First two tests utilized a 60-40 combination of glass and ACP while the third
WORK test utilized a 60-40 combination of glass and MDF. The fourth test utilized standard rated material. For a better quantitative estimate on ‘how much better are rated materials’ on a system level, more such tests are
required.
an all glass façade with spandrel area being covered using masonry.
• Glass panels usually fall out in intact form due to failure of the sealant material or melting/excessive deformation of the aluminium cladding
frame. A drastically different behavior was observed in Test 4, where glass panels demonstrated significant concave outward bending due to
heat before they shattered. This is possibly due to the constraining effect of the masonry spandrel and needs to be investigated further.
• Insulation material used in ACP is of major concern as it has a potential to initiate secondary fires, as observed in Test 1 and Test 2. ACP with
different insulting materials need to be investigated in detail to assess such risks. Ideally, a non-inflammable material should be used for such
applications.
• MDF panels responded better compared to ACP. They did not catch fire readily and sustained much longer than the ACP. This was due to the
inflammable core of ACP which aided in burning.
• Workmanship is an important component in installation of fire protection systems. Failure of fire stop materials as well as cement boards
used for structural fire protection was observed in Test 2, attributed to poor workmanship.
• Test 4 demonstrated another danger associated with façade systems. Since fire spread internally from ground floor to first floor, intense flames
developed on first floor without breaking any glass panels (possibly due to constraining effect of masonry spandrel). This rendered the
firefighting operation very difficult. Fire was controlled only after several attempts to break the glass by water jet impingement. Provisions for
breaking façade systems as and when necessary by the firefighters is an important safety consideration.
