1. Baksi, et al., International Journal of Advanced Engineering Technology E-ISSN 0976-3945
Int J Adv Engg Tech/Vol. VI/Issue I/Jan.-March,2015/
Research Paper
QUALITATIVE ANALYSIS OF THE DIFFERENCE IN FIRE
LAG TIME OF FIBRE-REINFORCED CONCRETE AND
NORMAL CONCRETE, COATED WITH PLASTER OF PARIS
COMPRISING OF GRANULATED CHARCOAL
Soumyadeep Baksi1
*, Dr. Nihal Anwar Siddiqui2
and Dharani Kumar K.3
Address for Correspondence
1
M.Tech (Disaster Management), 2
Associate Professor & Head,3
Assistant Professor, Department of Health
Safety & Environment, University of Petroleum & Energy Studies, Dehradun INDIA
ABSTRACT:
There has been a significant increase in utility of fibre reinforced concrete over the couple of decades owing to the fact that it
has an improved set of properties in the form of tensile strength, ductility, flexural strength and most important of the
serviceability period of a normal structure as well as a super structure. Moreover fibre concrete has too has a vehement
application in the retrofitting of pre-existing structures. This paper reflects the procedure of introducing carbon fibres of
450mm length and volume fraction up to 1% and enveloping that in 2 mm of plaster of paris with double coating, and
granulated charcoal added to it and estimate the time lag of fire point of concrete and establish the fact that charcoal is a
good smoke absorbent in building purposes. This paper comprises of the details of the investigation and experiments and
draws substantial conclusion or inference from that.
KEYWORDS: composite materials, fibre reinforced concrete, tensile strength, flexural strength, high performance fibre
reinforced concrete. Etc.
1. INTRODUCTION
The most fascinating property of concrete for which
it is preferred over any other building construction
material is that it is strong in compression and weak
in tension. Whenever the concrete cracks, it’s unable
to bear the tensile load. To make the concrete
competent for absorbing larger value of tensile loads
at which the process of cracking initiates we need to
extend expertise in delivering concrete with
properties of better tensile and flexural stresses. To
increase the tensile stress and correspondingly to
enhance the flexural stress levels fibres are added
which are instrumental in providing an even better
upliftment of properties pertaining to the above
mentioned stresses under consideration as the
addition of the fibres converts the concrete matrix
into a composite material whose property differ
substantially from normal concrete. The next part
draws our attention to a vital aspect – “fire and its
safety implications in high rise occupancies”. With
the exponential increment of industrialization and
urbanization the requirement of land to cater to the
diversified necessities of the existing population in
forms of assets, manufacturing process for product
generation, energy needs and various other GDP
enhancing processes. Thus requires the need to house
more and more population within a stipulated area
provided. Fire in such occupancies generally arises
to the extensive wirings, illegal smoking zones,
improper safety implications in high rise buildings
etc. Whenever fire crops up, in the building premises
it becomes extremely dreadful and takes shape of a
monster of death. Thus it becomes of extreme
urgency to save the lives of the occupants as statistics
have shown that most of the deaths occur owing to
smoke that has been generated in due course of time.
Thus this paper demonstrates the step by step
investigation into the experimental set up and thus
establishing the fact of utilizing charcoal as an
effective smoke retardant and prior to that we need to
effectively enhance the tensile strength and flexural
strength of concrete by addition of fibre
reinforcement.
2. MATERIAL USED
2.1 Cement
Cement forms the basis of any structure – as an
important constituent to form the stone like matrix
called concrete. The mixture in its early stage is
known as ‘Green Concrete’- and can be molded into
any form. The cement thus utilized in this experiment
is OPC (Ordinary Portland Cement), of grade 43*
as per as IS 8112: 2013 to form M20# grade blocks.
The cement should confirm the following chemical
characteristics:
*grade of cement indicates the compressive strength at
the end of 28 days. Grade 43 cement can endure 43
Mega pascals at the end of 28 days.
#M20 indicates the force acting per unit area i.e. 20 N/ Sq
mm
N.B. The constituent ratio of
The specific requirement are needed in order to form
M20 grade concrete, essential for the providing
significant amount of strength to the concrete blocks
and the conditions in the following table also
determine why we have taken M20 grade concrete.
2.2 Composition Ratio of Sand, Cement,
Aggregate for the formation of Concrete
blocks of M20 Grade Concrete.
2.3 Calculation of the Ratio of the Ingredients
(Cement: Sand: Water)

2. Baksi, et al., International Journal of Advanced Engineering Technology E-ISSN 0976-3945
Int J Adv Engg Tech/Vol. VI/Issue I/Jan.-March,2015/
M20= 1:1.5:3
Volume= 1+1.5+3=5.5
Total volume of Ingredients for using = 1.57.
Volume of Broken Stones Required =
(3/5.5*1.57)=0.856 M3
Volume of Sand Required =0 .471 M3.
Volume of Cement= (1/5.5 *1.57)=0 .285M3
Weight of Cement required = 0.285*1440=411 bags.
2.4 Coarse Aggregate Requirements
The volumetric requirement of coarse and fine
aggregate for a 40mm sieve coarse aggregate, fine
aggregate Zone II was registered and the
corresponding water cement ratio 0.50 was 0.71 and
0.29 respectively.
2.5 Fibre Reinforcement
The fibres are instrumental in diminishing the
shrinkage cracking. Fibres are uniformly distributed
through the entire concrete matrix thus effectively
reducing the load distribution. Secondly the fibres
offer more resistivity to corrosion than steel bars used
for reinforcement. Finally fibre reinforcement
reduces the cost of laying down wires and meshes as
the later requires high cost of labour.
High volume fraction of Fibre reinforcement: It is
generally used to reduce the strain hardening of the
composite concrete matrix. Due to enhanced
properties these composites are often termed as
HPFRC (High Performance Fibre Reinforced
Composites).
3. SLUMP TEST
The slump test of cement is an exact test that
measures the workability of new cement. All the
more particularly, it gauges the consistency of the
solid in that particular bunch. This test is performed
to check the consistency of crisply made cement.
Consistency is a term nearly identified with
workability. It is a term which portrays the condition
of new cement. It alludes to the simplicity with which
the solid streams. It is utilized to show the level of
wetness.
Workability of solid is chiefly influenced by
consistency i.e. wetter blends will be more workable
than drier blends; however cement of the same
consistency may fluctuate in workability. It is
likewise used to focus consistency between
individual groups. The slump test was performed and
the following reports were obtained as per as IS:
1199-1599.
4. COMPACTING FACTOR TEST
Compacting element of crisp solid is done to focus
the workability of new cement by compacting
component .Compacting variable of new solid is
done to focus the workability of new cement by
compacting component test according to May be:
1199 – 1959. The device utilized is Compacting
variable apparatus according to Seems to be: 1199 –
1959.
5. COMPOSITION OF PLASTER OF PARIS
FOR COATING PURPOSE WITH
GRANULATED CHARCOAL
5.1. Actiated carbon, additionally called enacted
charcoal, initiated coal, or carbo activatus, is a
manifestation of carbon handled to have little, low-
volume pores that expand the surface region
accessible for adsorption or substance responses. One
noteworthy mechanical application includes
utilization of actuated carbon in the metal completing
field. It is generally utilized for purging of
electroplating arrangements. For instance, it is a
primary purging strategy for expelling natural
debasements from brilliant nickel plating
arrangements. A mixture of natural chemicals are
added to plating answers for enhancing their store
qualities and for improving properties like splendor,
smoothness, pliability, and so forth. Because of
section of direct present and electrolytic responses of
anodic oxidation and cathodic diminishment, natural
added substances create undesirable breakdown items
in arrangement. Their intemperate develop can
antagonistically influence the plating quality and
physical properties of kept metal. Enacted carbon
treatment evacuates such pollutions and restores
plating execution to the craved level.
5.2. Plaster-of-Paris, Covering the work zone with
a plastic mat or with daily papers. We have to locate
a blending compartment (ideally a dispensable one)
that could oblige the measure of mixture planned.
The perfect proportion for a Plaster of Paris mixture
is 2 sections Plaster of Paris powder to 1 section
water. Next we have to allot the water and empty it
into your blending compartment. Allot the Plaster of
Paris on another holder. Separate any pieces of
powder with a spoon. Keep in mind that the degree
ought to be 2 sections powder to 1 section water. In
the event that you apportioned some water in Step 1,
then you would require 2 mugs Plaster of Paris
powder. Begin including the Plaster of Paris powder
to the water in your blending compartment by
sprinkling or filtering the powder over the water. Try
not to include the powder in one spot, rather attempt
to cover as much range as you can. Keep including
the Plaster of Paris powder, tapping the sides of the
compartment occasionally. The sign to stop is the

3. Baksi, et al., International Journal of Advanced Engineering Technology E-ISSN 0976-3945
Int J Adv Engg Tech/Vol. VI/Issue I/Jan.-March,2015/
point at which you recognize that the powder is just
about covering the surface of the water and is not as
effectively consumed by the water. Typically this
point would be around the 2:1 degree yet could
fluctuate marginally relying upon a few elements,
including your image of Plaster of Paris and water
temperature.
Mix the granulated charcoal with Pop in ration of 1:5
and mix it thoroughly.
6. DIFFERENCE IN FIRE LAG TIME OF
NORMAL CONCRETE BLOCK AND
GLASS FIBRE REINFORCED CONCRETE
BLOCK
The two blocks after being formed and casted for 28
days to attain 90% strength. Measuring the
compressive quality of solid is attained to by taking
an example of solid at the time of situation. Barrels,
measuring 12 in. high by 6 in. in measurement, or 8
in. by 4 in., are compacted by a break machine that
applies expanding power upon the barrel until it
fundamentally breaks. At the point when a
disappointment happens (generally alluded to as a
"break"), the compressive quality is measured by
separating the power (lb) measured at the time the
chamber comes up short by the heap bearing surface
territory (sq in.) of the solid example. At the time of
the break, the example's age is for the most part noted
for quality certification purposes. Thusly, to meet the
regular cement compressive quality particular as
already noticed, the break results ought to figure to
no less than 5,000 psi at 28 days. At the point when a
detail has execution criteria of 5,000 psi at 28 days,
for instance, representing powers will need a test
record (two individual chamber breaks at 28 days) to
guarantee conformance with the determination.
Luckily, more than two
chambers are normally gathered for testing. Through
examination and exact information gathering,
projection of a 28-day quality from a three- or seven-
day test break is anything but difficult to perform and
results in an expected quality near to that deliberate at
28 days. With the precision of this early estimation, if
an issue emerges, it can be explored much sooner
than 28 days.
One of the blocks is being coated with Plaster of
Paris (POP) of 2” and a time delay of 30 minutes is
kept before the next coating in refurbished. Plaster of
Paris is a great material to use for basic sculptures
and craft projects because it is easy to prepare and
sets in a few minutes. Then both the blocks are
subjected to oxy acetylene flame from acetylene
flame Oxy-fuel welding (commonly called
oxyacetylene welding, oxy welding, or gas welding
in the U.S.) and oxy-fuel cutting are processes that
use fuel gases and oxygen to weld and cut metals,
respectively. And the fire time of both the blocks is
being noted given in the table above.
7. CONCLUSION
It is noticed that with the addition of Plaster-of-Paris
with granulated charcoal have been subsequently
effective in maintaining the tensile stress up to a
considerable extent and the time lag has been been
calculated with demonstrates that there has been a
change of 16.75 % of time increment when it comes
to fire lag time of the modified concrete block as
compared to the former block of normal PCC ( Plain
Cement Concrete) block.
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