So, let we take the first step towards Safety because we have been designing energy efficient
buildings for quite long, traditionally the passive architecture or currently the modern
architecture. There is lot of features been added to address the sustainability yeah we
know we do a building more for aesthetic too, but important criteria which has been lost
in the entire building process is the safety, that even glass buildings or glass facades
been part of building safety comes as a first criteria.
So, what mean what n b c mean for safety. N b c has very clear definition for what is
called safety glass, as per n b c the glass which does not break under most likely form
of human impact. So, it mean even as it is a general is an accidental procedure, somebody
is going to fall on the class even it can be in internal partition the glass should
have the ability to with stand the human impact low that is called safety glass. As this
case worst case scenario even if it breaks the likelihood of cutting or making any kind
of physical damage will has to be has to be the minimized does not include protection.
So, here is safety glass the word safety here does not mean it is not for vandalism, burglary,
explosion or for fire arms or any kind of natural disaster.
Here the definitions very clearly that, safety glass means; it is safety against human impact
because in case if i wanted to make my building safe against vandalism or for explosion or
for fire or for kind of a natural disaster, the design procedures has to be slightly different
and there are different standards it has to pass through different design consideration
I have to take into part during the design . So, the safety glass does not been classified
as a security glazing. So, even if I wanted to save my property building or my house
from burglary or any other external impact, this safety glass does not going to solve
the purpose. This product which is the safety glass as per n b c which is very clearly defines.
The toughened safety glass or laminated safety glass, here it means a glass which has a ability
to win higher resistance against human, which is toughened glass which is four times stronger
than an annealed glass or a laminated glass where I use polyvinyl butyl p v b which bonds
two portion of a glass two slice of a glass. So, that even as an impact heavy impact happened
the first glass break even a second glass will have a tendency to hold the glass one
or even at this condition of both the glasses break there is an p v b which holding the
class together. So, the glass will not come out of the frame.
So, it can still hold the resistance, only this two types of glass been named as safety
glass toughened safety glass or laminated safety glass. If I have to use a coated glass
as a part of this, then I have to use the coated glass in the format of toughened or
I have to laminated before using it in a building or it can be of a heat strengthened glass
for us argument, which is between the the impact resistance of heat resistance glasses
which lies between annealed and toughened. In that case if i have to use heat strengthened
glass then it has to be used in the laminated format.
So, where we can where to use this safety glass based on the different locations or
access. So, for example, there is a glass overhead, which has you can called as skylight
or it can be a horizontal skylight or it can be an inclined skylight or even in case of
in any other format even as a architecture or a part of a aesthetics the the facade is
going to be a stoked façade, the stoke can be towards inside or it can be an outside.
So, is there is a possibility of the glass can fall on somebody then ideally the glass
has to be safety glass as per the definition. Where as we use the glass were we are accessible,
we use a glass balustrades, we use glasses floor sometime, we use glasses stairs for
the um staircase application. So, in that case where are the human beings
or directly accessing or transferring the load over the glass? So, the glasses supposed
to take very high resistance against human impact this is what we call human impact.
In that case these applications has to be precisely a laminated glass laminated safety
glass for an example, the balustrades or the handrails, which has used in your shopping
malls which has an access or it has a possibility to fall on during a any kind of human impact.
So, it has to be very clearly laminated safety glass.
So. In fact, to make it very clear the n b c 20 session has a pictorial communication
I would say. So, based on the height of the building.
So, the buildings at a ground floor level which even the glass breaks going to just
shutter on the floor, you have not still has an provision as an access to go with the basic
kind of a class , but moment the glass is going to be above 2.1 meter or you have
a provision to touch the glass or you have a provision or the glasses in an inclined
format inclined format or in a sloped format or in a handrail the glasses has to be safety
glass. Again the safety you can divided based on the application in case of vertical facades
still you can go with a toughened glasses, where as there is no compromise when it goes
to be an incline or handrail purpose or for balustrade or for glass application glass
floor application or staircase application it has to be laminated safety glass.
So, moment I mean safety glass, it does not mean that any process glass can be named as
safety glass as a definition safety glass means we know it has to take human impact.
So, how to quantify it? So, there is a kind of or a list of test available as per a different
standards including a n or the current I S which is get to getting launched . So, there
is a list of test like whether impact or resistance to shock which is ideally called Ball Drop
test or Fragmentation Test, Wrap Test, Boil Test for laminated glasses, fracture and adhesion
test again for laminated UV light test, Short bag which is ideally for the human impact.
So, that you can understand or create an impact like human and then understand what happens
to the glass Light stability test. So, these are the list of test which is identified
in n b c 2016 as a procedure to go through any processed glass before getting installed
in the building, there should be a set of samples has to be taken during the processing,
it is ideally like how we do cube testing for concrete. So, you have to take a list
of set of samples send it to laboratories available which can do the testing currently
I I T Madras has this kind of a testing which can do this. So, that you will make ensure
that the processing procedures are follow. And the testing over the processed glass has
passed or followed the methodology as per the standersrequirement. So, based on whether
it is laminated safety or toughened safety there are few tests which are mandatory few
tests are kept as optional based on the functionality, which is very clearly detailed out in your
n b c 2016; for an example, the bake test and humidity test it is specifically for laminated
glass, where as safaris compression as four point bending or the waviness which very precisely
has to be done for toughened laminated glass toughened glass soft and safety glass.