Page 1 of 5
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online: https://ejbss.org/ P a g e | 2044
Durabiltiy Study on Fibre Reinforced Geo
Polymer Concrete
M.KIRISHNASEKAR
M.TECH – Structural Engineering
PRIST Deemed University, Madurai, Tamilnadu
Abstract—The deterioration rate of geopolymer concrete
specimens when exposed to aggressive environment was low
and the specimens were stable when compared to ordinary
Portland cement concrete. Attention was paid upon the
durability and flexural behaviour of glass fiber reinforced
geopolymer concrete specimens, manufactured using low
calcium class F fly ash, exposed to 10% concentration of
sulfuric acid attack and chloride attack for a period of 3,7,15
& 30 days. 110mm x 100mm cross-section and 500mm long
beams with 1% tensile reinforcement were cast. For Rapid
Chloride Penetration Test (RCPT), 100mm dia and 50mm
discs were cast. For water absorption test, 100mm x 100mm x
100mm cubes were cast. Glass fibers were added to the
concrete mix as 0.01%, 0.02%, 0.03% and 0.4% to the
volume of concrete.
I.INTRODUCTION
Utilization of concrete as a major construction
material is a worldwide phenomenon and the concrete
industry is the largest user of natural resources in the world.
This use of concrete is driving the massive global production
of cement, estimated at over 2.8 billion tones according to
recent industry data. Associated with this is the inevitable
carbon dioxide emissions estimated to be responsible for 5 to
7% of the total global production of carbon dioxide.
Significant in cement production have been observed and
were anticipated to increase due to the massive increase in
infrastructure and industrialization in India, China and South
America.
II.GEOPOLYMER CONCRETE
Geopolymer
The term geopolymer was introduced by Davidovits
(1978) proposed that an alkaline liquid could be used to react
with the Silicon (Si) and the aluminium (A1) in a source
material of geological origin or in by product materials such
as fly ash and rice husk ash to produce binders. The process
involves a chemical reaction under highly alkaline conditions
on Si-A1 minerals, yielding polymeric Si-O-A1-O bonds in
amorphous form. In terms of global warming, the geopolymer
technology could significantly reduce the CO2 emission to the
atmosphere caused by the cement industries.
Geopolymerisation
The chemical reaction that takes place in the case is a
polymerization process. Geopolymers are members of the
family of inorganic polymers. The chemical composition of
the geopolymer material is similar to natural zeolitic materials,
but the microstructure is amorphous. The polymerization
process involves a substantially fast chemical reaction under
alkaline condition on Si-A1 of Si-O-A1-O bonds (Davidovits,
1994). Geopolymerisation is the exothermic process that
describes the creation of a geopolymer. First, the sodium
hydroxide and sodium silicate solution dissolve the silicon and
aluminum that is found in fly ash. These dissolved ions then
undergo a condensation reaction, forming monomers in the
form of –Si-O-A1-O, -Si-O-A1-O-Si-O. Applying heat
between the temperatures of 600C and 80
0C for a period of
approximately 6 to 12 hours to these monomers causes them
to polymerize, or link together and form rigid chains. The
polymers are then allowed to harden, It is this process that
allows the creation of geopolymer concrete.
Durability properties
Geopolymer concretes have excellent durability
properties and excellent result for the same. The heat cured fly
ash based geopolymer concrete undergoes very little drying
shrinkage in the order of about 100 micro strains after one
year (Rangan et al, 2006).
The sulfuric acid resistance of geopolymer
concrete was evaluated based on the mass loss and the
residual compressive strength of the test spcimens after acid
exposure up to one year. The visual appearance of specimens
after exposure to sulfuric acid solution showed that the acid
attack slightly damaged the surface of the specimens. The
maximum mass loss of test specimens of about 3% after one
year of exposure.
Necessity of Geopolymer Concrete
Construction of residential buildings, industries and
infrastructures is gaining momentum in an upward trend
worldwide. Construction industries strive hard to meet out this
growing task. This ultimately leads to consumption of large
volume of ordinary Portland cement (OPC) concrete. OPC
concrete is the second largest product, next to water, being
consumed in the world. The prime constituent of OPC
concrete is cement. It is estimated that 2.2 billion tons of
Page 2 of 5
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online: https://ejbss.org/ P a g e | 2045
cement would be produced in the coming years throughout the
world. This large volume of cement production emits
greenhouse gas, into atmosphere. It is agreed that the emission
of Co2 by cement industries would be around 80% of
quantity of cement produced. This huge quantity of Co2 being
emitted into atmosphere is increasing every year due to
exponential growth in the production of cement. This emission
of greenhouse gas is quite alarming and urgently requires an
alternate to cement in construction industry. Since
Geopolymer concrete doesn’t use any cement, the production
of cement shall be reduced and hence the pollution of
atmosphere by the emission of carbon dioxide shall also be
minimized.
Applications
A recent life cycle assessment of geoploymer
concretes indicates that the global warming potential (GWP)
of geoploymer concretes is between 26 and 45% lower
compared to ordinary Portland cement concrete. This is
largely ascribed to the sodium silicate and sodium hydroxide
production. The impact of each depends upon the processing
employed.
The use of fly ash-based Geopolymer concrete
contributes to the potential for reduced global warming.
The use of alkaline solutions form waste streams of other
processes, such as aluminium processing, may provide
potential reduction in the environmental impact of geoploymer
concrete.
The price of raw resources for geoploymer concrete is
much cheaper than that of Portland cement. Fly ash is
incredibly inexpensive and in some cases free.
The recycling of fly ash, which is an industrial waste
product, makes in an urbanizing world.
Totally eliminate cement in Geopolymer concrete.
In the short term, there is large potential for
geoploymer concrete applications for bridges, such as precast
structural elements and decks as well as structural retrofits
using geoploymer-fibre composites. Geoploymer technology
is most advanced in precast applications due to the relative
ease in handling sensitive materials (e.g. high-alkali activating
solutions). Other potential applications are precast pavers &
slabs for paving, bricks and precast pipes.
Limitations
Available in the base material fly ash to the required location.
High cost for the alkaline solution.
Safety risk associated with the high alkalinity of the activating
solution.
Practical difficulties in applying Steam curing / high
temperature curing process.
Considerable research is ongoing to develop geopolymer
systems that address these technical hurdles.
III.FIBRE REINFORCED GEOPOLYMER CONCRETE
Cementitious materials are generally brittle and have an
inherent weakness in resisting tension. They crack under low
levels of tensile stress and usually fail by sudden propagation
of these cracks. In order to prevent brittle failure, an
appropriate load carrying mechanism must be provided across
the crack such as, for example, steel reinforcement.
A similar concept is applicable for the case of fibre
reinforced geoploymer concrete (FRGPC), where
discontinuous fibres are added as reinforcement to bridge
cracks and to transmit tensile stress across a crack, thereby
improving the performance of the composite structure.
The concept of using fibre reinforcements to improve
the tensile characteristic of binding materials dates back to
ancient Egyptian times where straw was mixed with mud for
masonry construction. Further, the Romans used horse hair to
reduce shrinkage in their concrete mixes (IIIston, 1996).
To-date, several different types of fibres are available,
both natural and artificial. The selection of the type of fibre is
guided by its mechanical and chemical properties as well as
extent the fibres influence the matrix properties.
The fibres commonly used in FRGPC are often divided into
two broad categories:
Low modulus, high elongation fibres such as nylon,
polypropylene and polyethylene in which the fibres enhance
primarily the energy absorption characteristics only.
High strength, high modulus fibres such as steel, glass and
asbestos in which the fibres enhance the strength as well as the
toughness of the composites.
The application of fibre reinforced geopolymer composites are
varied and dependent on the type of fibres that have been
used. Synthetic fibres, such as polyethylene, are used to
improve resistance to cracking caused by drying shrinkage.
Glass fibres are typically used in production of thin sheet
products such as precast architectural panels due to their
capability of producing relatively light weight and thin
sections. In such an application, the glass fibres act as the
primary reinforcement and special production methods used in
manufacturing of the composite (Balaguru and Shah, 1991).
IV.AIM AND SCOPE OF THE INVESTIGTION
Aim Of The Investigation
This research aimed at investigating the durability of
glass fibre reinforced geopolymer concrete. The aim of this
work is to experimental investigate the durability
characteristics of Fibre Reinforced Geopolymer Concrete.
Page 3 of 5
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online: https://ejbss.org/ P a g e | 2046
To study the durability of Fibre reinforced
geopolymer concrete the following testes were done
Sulphuric acid resistance test
Chloride resistance test
Water absorption test
Rapid Chloride Penetration Test (RCPT)
To compare the results of the above mentioned tests
for various percentages of glass fibre such as 0.01%, 0.02%, ,
0.03% and 0.04% of the total volume of concrete.
Scope Of The Investigation
The research utilized low-calcium (ASTM Class F)
Indian fly ash as the source material for manufacturing all the
Geopolymer concrete specimens. This fly ash was obtained
from Tuticorin Thermal Power Station, Tamilnadu, India.
The scope of work involved the following:
Geopolymer concrete of suitable proportions have
been chosen and tried with Class F Indian fly ash.
Manufacturing and studying the durability response
of Fibre reinforced Geopolymer concrete cubes, cylinders and
beam subjected to sulfuric acid and chloride attack, and
comparing the test results with that of specimens made out of
Geopolymer concrete.
Geopolymer materials have attracted a great
attention and are still increasing their popularity in
construction industry and building engineering because of
their capability to restrain CO2 emissions, together with their
rapid strength development, low shrinkage and excellent
corrosion and fire resistance. Producing geopolymer binders
would not be so detrimental to environment as producing
ordinary Portland cement (OPC), thanks to the lower process
temperature characterizing geopolymers production
technology. Geopolymers have been recently regarded as
promising substitutes for OPC in different applications fields,
including that of engineered fibre reinforced composite
materials based on cementitious or inorganic matrices. In the
past years, in facts, fibre reinforced composite materials have
been playing an important role in rehabilitation and repair of
damaged masonry and concrete structures, thanks to their
performing properties such high strength to weight ratio,
corrosion resistance and ease of application.
V.METHODOLOGY
The main objective of this investigation is to
study the durability of fibre reinforced geopolymer concrete and
compare it with ordinary geopolymer concrete.
Materials
The materials used for making fibre reinforced
geopolymer concrete specimens are low-calcium class F fly ash
as the source material, fine aggregate, coarse aggregate, glass
fibre, alkaline liquids, water and superplasticzer.
Fly Ash
Any material rich in silica and alumina in glassy
powder form is apt for acting as a source material in the
synthesis of Geopolymeric binder and consequently,
Geopolymer concrete. Since high calcium Indian flyash contains
excess quantity of calcium and sulfate in it, which may disturb
the polymerization action, ASTM Class F low calcium fly ash
has been preferred. Indian flyashes are heterogeneous in nature,
greyish white in colour, contain moisture less than 0.3% by
weight, loss on ignition 0.9%, bulk density 1047Kg/m3
, specific
gravity 2.16 and with some traces of Sulphur trioxide. An X-Ray
Fluorescene (XRF) analysis done to determine the chemical
composition of low calcium flyash used in this experimental
program is shown in Table 4.1. Flyash is obtained from
Tuticorin Thermal Power Station , Tamilnadu, India and
contained 1.26% of CaO by weight and hence has been
designated as Class F fly ash. From the composition of fly ash,
it is obvious that Indian flyash contains more silica and the ratio
silica to alumina is approximately 3 whereas in Australian
flyash, the ratio is approximately 2.
Glass Fibres
Glass fibres are characteristic for their high strength,
good temperature resistance, and corrosion resistance. The lass
fibre has a length of 12mm and nominal diameter of 0.014 mm
was used. The unit weight of the glass fibre is 2670kg/m3
.
Glass fibre is shown in Figure 4.1.
Superplasticizer
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