project work of civil engineer

1. i | P a g e
“STRUCTURAL MEMBERS ARE STRENGHTENED WITH
LOW-CALCIUM FLY ASH IN GEO POLYMER
CONCRETE”
A PROJECT REPORT SUBMITTED TO JAWAHARLAL
NEHRU TECHNOLOGICAL UNIVERSITY KAKINADA IN
THE PARTIAL FULFILLMENT FOR THE AWARDOF THE
DEGREE OF
MASTER OF TECHNOLOGY
IN
STRUCTURAL ENGINEERING
Submitted by
GAJAM SUNIL KUMAR
209H1D8705
Under the noble guidance of
MR. PARSINENI BALA KRISHNA M-TECH
Assistant PROFESSOR
DEPARTMENT OF CIVIL ENGINEERING
NEWTON’S INSTITUTE OF SCIENCE & TECHNOLOGY
AFFLIATED TO JNTUK UNIVERSITY
MACHERLA-522426
ANDHRA PRADESH

2. ii | P a g e
NEWTON’S INSTITUTE OF SCIENCE AND TECHNOLOGY
AFFLIATED TO JNTUK UNIVERSITY
DEPARTMENT
OF
CIVIL ENGINEERING
BONAFIED CERTIFICATE
This is to certify that the project entitled
“STRUCTURAL MEMBERS ARE STRENGHTENED WITH
LOW-CALCIUM FLY ASH IN GEO POLYMER CONCRETE” is
a bonafied work of GAJAM SUNIL KUMAR [209H1D8705] in the
partial fulfillment of the requirement for the award of the degreeof Master of Technology in
structural engineering This work is done under my supervision and guidance.
INTERNAL GUIDE HEAD OF THEDEPARTMENT
Mr. PARSINENI BALA KRISHNM-TECH Mr. PARSINENI BALA KRISHNA M-TECH
Asst.Professor Asst.Professor
Civil Engineering Civil Engineering
External Examiner.

3. iii | P a g e
DECLARATION
I hereby declare that the project work titled “STRUCTURAL
MEMBERS ARE STRENGHTENED WITH LOW-CALCIUM FLY
ASH IN GEO POLYMER CONCRETE” has been carried out by me
and no part of it has been submitted for the award of any degree or
diploma at any other university or institutions.
GAJAM SUNIL KUMAR
[209H1D8705]

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ACKNOWLEDGEMENT
I am extremely grateful to Dr. G. JAGADEESWAR REDDY, Principal and.
Asst.Prof. Mr. PARSINENI BALA KRISHNA M-TECH HOD, Department of Civil
Engineering, Newton’s institute of science & technology, Macherla, for giving us
an opportunity to take up the project.
I am extremely thankful to Asst.Prof. Mr. PARSINENI BALA KRISHNA M-TECH
Project Coordinator and Internal Guide, Department of Civil Engineering for his
constant guidance, encouragement and moral support throughout the project.
I will be failing in duty if I do not acknowledge with grateful thanks to the authors of
the references and other literatures referred in this Project.
I express my thanks to all staff members and friends for all the help and co-ordination
extended in bringing out this Project successfully in time.
Finally,
I am very much thankful to my parents who guided me
every step.
GAJAM SUNIL KUMAR
[209H1D8705]

5. 10
ABSTRACT
Water is the only resource that is used more often than concrete globally. Portland
cement is necessary since it is an integral component of traditional concrete. During
the manufacture of one tonne of cement, about one tonne of carbon dioxide is
discharged into the atmosphere. In addition, the manufacture of cement uses a
significant amount of energy and natural resources, ranking right up there with the
production of steel and aluminium. The expansion of various infrastructure types is
directly contributing to an increase in the amount of concrete used. To meet the rising
demand for concrete, should we expand our cement production facilities or look into
other binders?
On the other hand, there is already a significant worldwide production of fly ash. The
bulk of this fly ash is not being used to its full potential, and a sizeable portion of it is
being dumped in landfills. The amount of fly ash produced would rise in direct
proportion to the increased energy demand.
Both of the aforementioned problems are addressed by the work we did. As a result of
our extensive research, we have gained the knowledge and expertise necessary to
produce low-calcium fly ash-based geopolymer concrete. More than 30 technical
papers that were presented at various international conferences used our work as their
foundation.
The behaviour and strength of reinforced low-calcium fly ash-based geopolymer
concrete structural beams and columns are examined in this research article.
Development, Mixture Proportions, Short-Term Properties, and Long-Term Properties
of Low-Calcium Fly Ash-Based Geopolymer Concrete were previously addressed in
Research Reports GC1 and GC2 of the Geopolymer Concrete Research Series.
High compressive strength, very little drying shrinkage, very little creep, excellent
resistance to sulphate attack, and good acid resistance are all characteristics of
geopolymer concrete that has been heat-cured and is based on low-calcium fly ash. It
may be used in a number of scenarios, including infrastructure. One tonne of low-
calcium fly ash may produce 2.5 cubic metres of excellent geopolymer concrete.

6. 10
Additionally, the price of the chemicals required to make this concrete is less
expensive in bulk than the price of a tonne of Portland cement. As a result,
geopolymer concrete made from low-calcium fly ash is more affordable than Portland
cement concrete. This is due to the perception of fly ash as a resource for trash. The
unique characteristics of geopolymer concrete have the potential to significantly boost
the financial advantages. Additionally, the elimination of one metric tonne of carbon
dioxide results in the creation of one carbon credit, each of which is worth around
twenty euros. This carbon credit significantly improves the economic benefits that
geopolymer concrete provides. Generally speaking, using geopolymer concrete has a
lot of benefits.

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TABLE OF CONTENTS
PREFACE 2
ACKNOWLEDGMENTS 3
TABLE OF CONTENTS 4
CHAPTER 1 INTRODUCTION 7
1.1 Background 7
1.2 Research Objectives 9
1.3 Scope of Work 9
1.4 Report Arrangement 10
CHAPTER 2 LITERATURE REVIEW 11
2.1 Introduction 11
2.2 Geopolymer Materials 11
2.3 Use of Fly Ash in Concrete 13
2.4 Fly Ash-based Geopolymer Concrete 13
CHAPTER 3 SPECIMEN MANUFACTURE AND TEST PROGRAM 14
3.1 Introduction 14
3.2 Beams 14
3.2.1 Materials in Geopolymer Concrete 14
3.2.1.1 Fly Ash 14
3.2.1.2 Alkaline Solutions 15
3.2.1.3 Super Plasticiser 16
3.2.1.4 Aggregates 16
3.2.2 Mixture Proportions of Geopolymer Concrete 16

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3.2.3 Reinforcing Bars 17
3.2.4 Geometry and Reinforcement Configuration 17
3.2.5 Specimen Manufacture and Curing Process 19
3.2.6 Test Set-up and Instrumentation 23
3.2.7 Test Procedure 24
3.2.8 Properties of Concrete 25
3.3 Columns 27
3.3.1 Materials in Geopolymer Concrete 27
3.3.1.1 Fly Ash 27
3.3.1.2 Alkaline Solutions 28
3.3.1.3 Super Plasticiser 28
3.3.1.4 Aggregates 29
3.3.2 Mixture Proportions of Geopolymer Concrete 29
3.3.3 Reinforcing Bars 30
3.3.4 Geometry and Reinforcement Configuration 30
3.3.5 Specimen Manufacture and Curing Process 32
3.3.6 Test Set-up and Instrumentation 34
3.3.7 Test Procedure 38
3.3.8 Concrete Properties and Load Eccentricities 40
CHAPTER 4 PRESENTATION AND DISCUSSION OF TEST
RESULTS 41
4.1 Introduction 41
4.2 Beams 41
4.2.1 General Behaviour of Beams 41
4.2.2 Crack Patterns and Failure Mode 42
4.2.3 Cracking Moment 45
4.2.4 Flexural Capacity 47
4.2.5 Beam Deflection 50
4.2.6 Ductility 57
4.3 Columns 59
4.3.1 General Behaviour of Columns 59
4.3.2 Crack Patterns and Failure Modes 60

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4.3.3 Load-Deflection Relationship 61
4.3.4 Load-Carrying Capacity 68
4.3.5 Effect of Load Eccentricity 68
4.3.6 Effect of Concrete Compressive Strength 69
4.3.7 Effect of Longitudinal Reinforcement 70
CHAPTER 5 CORRELATION OF TEST AND CALCULATED
RESULTS 72
5.1 Introduction 72
5.2 Reinforced Geopolymer Concrete Beams 72
5.2.1 Cracking Moment 72
5.2.2 Flexural Capacity 73
5.2.3 Deflection 75
5.3 Reinforced Geopolymer Concrete Columns 76
CHAPTER 6 CONCLUSIONS 78
6.1 Reinforced Geopolymer Concrete Beams 78
6.2 Reinforced Geopolymer Concrete Columns 80
REFERENCES 82
APPENDIX A Test Data 86
A.1 Beams 86
A.2 Columns 98
APPENDIX B Load-Deflections Graphs 110
B.1 Beams 110
B.2 Columns 114
APPENDIX C Data Used in Calculations 120
C.1 Beams 120
C.2 Columns 120

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CHAPTER 1
INTRODUCTION
This Chapter describes the background, research objectives and scope of work. An
overview of the Report arrangement is also presented.
1.1 Background
Combining concrete with During the production process, Portland cement is made by
mixing Portland cement, aggregates, and water together. Portland cement is the primary
component of Portland cement. Concrete is the material that is used in the building
industry more often than any other kind of substance. According to a number of different
estimations, the annual demand for concrete around the globe is predicted to reach
somewhere in the neighbourhood of 8.8 billion tonnes (Metha 2001). In the not too
distant future, there will be a rise in the demand for concrete as a direct result of the rising
number of infrastructure modifications that are planned for the future.
The production of Portland cement leads to the release of a significant amount of carbon
dioxide (CO2) into the environment around the facility. The emission of this gas accounts
for a significant fraction of the overall quantity of greenhouse gases. It is anticipated that
one tonne of carbon dioxide will be released into the atmosphere during the
manufacturing of one tonne of Portland cement. This figure was derived using standard
industry practises. The manufacturing of Portland cement is responsible for the release of
around 1.6 billion tonnes of carbon dioxide into the atmosphere. This figure is
comparable to about 7% of the total amount of carbon dioxide released into the
atmosphere globally (Metha 2001, Malhotra 1999; 2002).It is anticipated that global use
of cement will approach 2 billion tonnes by the year 2010, which, in turn, will lead to the
release of close to 2 billion tonnes of carbon dioxide. In order to mitigate the negative
impact that Portland cement has on the surrounding natural environment, the production
of concrete must make use of other binders.
One of the approaches that is being taken in order to produce concrete that is less
detrimental to the health of the surrounding environment is the use of by-product

11. 10
materials in concrete, such as fly ash, as an alternative to Portland cement. This is one of
the approaches that are being taken in this endeavour. The invention of high volume fly
ash (HVFA) concrete is a noteworthy accomplishment in this area. Despite containing up
to 60% fly ash in its composition, this type of concrete has remarkable mechanical
properties and outperforms conventional concrete in terms of endurance.Another term for
HVFA concrete is "high volume fly ash concrete." This kind of concrete is sometimes
abbreviated as HVFA concrete. According to the findings of the trials, concrete made
with HVFA may have a longer lifespan than concrete made with Portland cement
(Malhotra 2002).
Another approach to making concrete that is easier on the environment is to manufacture
an inorganic alumina-silicate polymer. This approach, which goes by the brand name
Geopolymer, is one of the options available. This material might originate from materials
that have a geological origin or it could come from by-product materials like fly ash,
which is rich in silicon and aluminium. Either way, there are two possible origins for this
substance (Davidovits 1994, 1999).
Fly ash, which can be found all over the world but has only seen a limited amount of use
up to this point, is one of the sources of ingredients that go into the production of
geopolymer binders. This is one of the reasons why fly ash is one of the sources of
ingredients that go into the production of geopolymer binders. Fly ash is one of the
sources of components, and this utilisation of it is one of the sources. In 1998, it was
projected that the annual worldwide output of coal ash was more than 390 million tonnes.
However, the portion of that production that was utilised was less than 15 percent
(Malhotra 1999). The fly ash used in the production of concrete accounts for only about
18 to 20% of the total yearly output of fly ash in the United States. This proportion is
much lower than the average throughout the world. This is the situation in spite of the
fact that the annual production of fly ash in the United States is around 63 million tonnes
(ACI 232.2R-03 2003).
In the not-too-distant future, there will be a rise in the production of fly ash, particularly
in nations such as China and India. By 2010, the annual output of fly ash would be
around 780 million tonnes, and only these two countries would be responsible for
producing it (Malhotra 2002). In light of this, it is of the utmost significance that efforts
be made to use this by-product material in the making of concrete in order to make
concrete more eco-friendly. This is so that concrete may be produced in a more

12. 10
sustainable manner. It is possible to achieve this goal by using recycled glass in the
mixture. For example, if one million tonnes of Portland cement were replaced with one
million tonnes of fly ash, this would result in the conservation of one million tonnes of
lime stone, 0.25 million tonnes of coal, and more than 80 million units of electricity.
Utilizing fly ash is one way to attain this goal. In addition to this, there will be a decrease
of 1.5 million metric tonnes in the total amount of carbon dioxide emissions emitted into
the atmosphere (Bhanumathidas and Kalidas 2004).
In view of the aforementioned, significant research on low-calcium fly ash-based
geopolymer concrete was initiated in the year 2001. This was done in response to the
aforementioned. This action was taken as a direct response to the previous two points.
Earlier Research Reports GC1 and GC2 provide comprehensive descriptions of the
formulation and manufacture of geopolymer concrete. These reports also covered the
material's immediate and long-term qualities (Hardjito and Rangan 2005; Wallah and
Rangan 2006). It was discovered that heat-cured low-calcium fly ash-based geopolymer
concrete exhibited an extraordinary resistance to sulphate and acid attack, a high
compressive strength, very little drying shrinkage, and a very low creep rate. These
characteristics have been uncovered. During the course of the investigation, certain
characteristics came to light. Other researchers' findings (Davidovits, 1999) suggest that
geopolymers have a high resistance to fire and do not experience an alkali-aggregate
reaction (Cheng and Chiu, 2003).
The investigation that is published in Research Reports GC1 and GC2 is supplemented by
the work that is detailed in this report, which illustrates the use of geopolymer concrete
that is heat-cured, low in calcium, and based on fly ash in large-scale reinforced concrete
beams and columns. The research that was published in Research Reports GC1 and GC2
can be found here.
1.2 Research Objectives
The fundamental goals of this investigation are to carry out research that is both
experimental and analytical in nature, with the intention of determining, among other
things, the following:
 The flexural behaviour of reinforced geopolymer concrete beams includes the flexural
strength of the beams in addition to their fracture pattern, deflection, and ductility. a
way of acting characterised by flexing

13. 10
 An inquiry has been made into the behaviour and strength of reinforced geopolymer
concrete slender columns when they are exposed to axial load and bending moment.
This inquiry is carried out in the context of an investigation.
 The degree to which the results of testing and the techniques of prediction that are now
being employed for structural components that are constructed of reinforced Portland
cement concrete have a connection with one another depends
1.3 Scope of Work
The scope of work involved the following:
 Make advantage of the research that has been published in Research Reports GC1
and GC2 in order to identify the proper geopolymer concrete mixes that are essential
for the fabrication of the reinforced test beams and columns (Hardjito and Rangan
2005, Wallah and Rangan 2006). These reports were written in part by Hardjito and
Rangan, who both made contributions.
 produce and evaluate twelve simply supported reinforced geopolymer concrete
rectangular beams, with the load progressively rising over the course of the test. The
ratio of the longitudinal tensile reinforcement to the compressive strength of the
concrete will function as the test variables.
 Produce and evaluate twelve square columns made of reinforced geopolymer
concrete using short-term eccentric loading. These columns should be produced. The
load eccentricity, concrete compressive strength, and longitudinal reinforcement
ratio are the test variables for this project.
 Carry out the necessary arithmetic computations in order to provide an accurate
prediction of the strength and the amount of deflection which will be experienced by
geopolymer concrete test columns and beams. This can be accomplished by utilising
the techniques that are now available for the design of concrete members. Make
advantage of the methods that are already accessible for cement concrete members in
order to accomplish this goal.
 When constructing reinforced concrete beams and columns, it is essential to
investigate the degree to which the outcomes of tests and calculations coincide with
one another. Additionally, it is necessary to provide data that supports the utilisation
of heat-cured, low-calcium geopolymer concrete that is formed from fly ash.

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1.4 Report Arrangement
The Report comprises six Chapters.
Chapter 2 presents a brief review of literature on geopolymers. The manufacture of
test specimens and the conduct of tests are described in
Chapter 3. Chapter 4 presents and discusses the test results. The correlations of
analytical results with the test results are given in
Chapter 5. The conclusions of this work are given in
Chapter 6. The Report ends with a list of References and Appendices containing the
details of experimental data.

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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
In the next chapter, some of the more fundamental characteristics of geopolymers
and geopolymer concrete will be covered. In addition to the reviews that were
presented in Research Reports GC1 and GC2, respectively, this paper serves as a
supplemental review (Hardjito and Rangan 2005, Wallah and Rangan 2006).
2.2 Geopolymer Materials
Davidovits (1988) was the first person to use the term "geopolymer" to refer to the
mineral polymers that were generated as a direct consequence of geochemistry. He did
so in referring to the mineral polymers that were referred to in the previous sentence.
This expression was used by him to refer to the mineral polymers that were developed.
He was referring to the mineral polymers that were produced as a direct result of
geochemistry when he used this term.In particular, he was speaking about the process
through which they came into being. A geopolymer is an inorganic alumina-silicate
polymer that is produced by synthesising mostly silicon (Si) and aluminium (Al)
material that is either of geological origin or material that was produced as a by-
product. This process generates a geopolymer that is mostly composed of silicon (Si)
and aluminium (Al). There are many other fields of endeavour in which geopolymers
may be put to use, including the fields of aeronautical engineering, the energy
business, and the building and construction industries. This process is referred to as
"synthesis" in the scientific lexicon. Although the geopolymer materials have an
amorphous form, their chemical composition is quite similar to that of zeolite. In spite
of the fact that their morphology is amorphous, this is the case (Davidovits 1999). The
process of synthesis, also known as the process of producing building blocks, involves
the joining of atoms of silicon and aluminium in order to finish the process. Synthesis
is the method by which building blocks are manufactured. On both a chemical and
physical level, these structural components are quite similar to the ones that are

16. 10
employed to bind the natural rocks together. They both serve the same purpose when
utilised.
The great bulk of the research that has been done on this material up to this point has
been on the geopolymer pastes. Ground blast furnace slag was one of the materials
that was used in the process that was established by Davidovits and Sawyer (1985) for
the manufacturing of geopolymer binders. This was a component of their technique as
well as a phase in the process that they followed. This kind of binder, which was
developed in the United States of America and given the label Early High-Strength
Mineral Polymer when it was granted a patent there, was used as an additional
cementing component. The patented innovation is known as "Early High-Strength
Mineral Polymer," and it was given that name for obvious reasons. In addition to it, a
pre-packaged ready-made mortar solution was developed. When it comes to the rate at
which it gains strength, this package simply needs the addition of mixing water as the
one additional component in order to produce a substance that is both highly efficient
and stable throughout the course of its development. This material was used in the
restoration of concrete airport runways, aprons, and taxiways, as well as the decks of
highways and bridges, as well as in various new constructions where it was important
to have high early strength. Additionally, this material was utilised in the construction
of bridges and highways. In addition to that, it was included in the building of a
number of other bridges. The one and only further step that needed to be taken was to
include some water for the purpose of mixing.
In addition to its use as an adhesive in the process of reinforcing structural
components, geopolymer has also been put to use in this application as a substitute for
organic polymer. This use comes about as a result of the fact that geopolymer is more
durable than organic polymers. One example of a pattern that has emerged over the
course of the last several years is shown below. It was found that geopolymers could
resist the heat of fire and keep their integrity even when exposed to ultraviolet light.
[There must be other citations for this]. (Balaguru et al., 1997).
Using two distinct kinds of fly ash, the researchers (van Jaarsveld, van Deventer,
and Schwartzman 1999) carried out a series of experiments on geopolymers. This
research concentrated mostly on the properties of geopolymers as their subject matter
of inquiry. The researchers came to the conclusion that the compressive strength of the
material fluctuated anywhere from 5 to 51 MPa after observing it for a period of 14

17. 10
days while it was left to its own devices. This conclusion was reached on the basis of
the findings that they gathered. The manner in which the components were combined
was one of the many factors that had an effect on the compressive strength of the
material; among these factors was also the total number of constituent parts. The
chemical composition of the fly ash was still another factor to consider. A higher
concentration of CaO led to a reduction in the porosity of the material's
microstructure, which in turn led to an increase in the material's compressive strength.
In addition to that, the ratio of water to fly ash that was used was still another factor
that was taken into consideration when calculating the strength of the material. It was
found that the compressive strength of the binder increased in a way that was
proportional to the decrease in the ratio of water to fly ash that was present in the
mixture. This discovery was made. This was a finding that required some educated
speculation in order to figure out completely.
Palomo, Grutzeck, and Blanco (1999) investigated the aspects of the material's
composition that contributed to its compressive strength. The curing temperature, the
curing duration, and the ratio of alkaline solution to fly ash were the issues in question.
It was discovered that the compressive strength was affected not only by the
temperature at which the material was allowed to cure but also by the amount of time
that it was allowed to cure for. This was the case regardless of whether the material
was allowed to cure at room temperature or at a higher temperature. Experiments led
to the discovery of this information. The highest possible degree of hardness was
achieved by combining the use of sodium hydroxide (NaOH) with the application of a
solution containing sodium silicate. This resulted in the utmost degree of hardness that
could possibly be achieved (Na2Si3). The material achieved a compressive strength of
up to 60 MPa after being cured for five hours at a temperature of 85 degrees Celsius,
which is an exceptionally high number.
As a continuation of the research that Xu and van Deventer had been doing before, in
the year 2000 they looked at the geopolymerization of 15 naturally occurring Al-Si
minerals. This was done as part of the inquiry that they had conducted earlier. It was
discovered that the minerals that had a greater degree of dissolution displayed a
stronger compressive strength than the other minerals. This was the case in contrast to
the other minerals. As it turned out, this was the correct interpretation. The
compressive strength was significantly affected by a number of different factors, some
of which included the percentage of calcium oxide (CaO) and potassium oxide (K2O),

18. 10
the molar ratio of silicon to aluminium in the source material, the type of alkali, and
the molar ratio of silicon to aluminium in the solution while it was being dissolved.
Other factors that had a significant impact on the compressive strength include the
temperature at which the material was compressed.
Swanepoel and Strydom have released the findings of a study that they conducted on
geopolymers as part of their research. This study was on geopolymers (2002). In order
to produce the geopolymers, fly ash, kaolinite, sodium silica solution, sodium
hydroxide, and water were mixed together in the appropriate proportions and then
heated. Both the length of time spent curing and the temperature at which it was done
had an effect on the material's compressive strength. However, the specimens reached
their utmost potential strength after being heated to sixty degrees Celsius and curing
for forty-eight hours. This procedure was carried out a total of three times.
Van Jaarsveld, van Deventer, and Lukey (2002) investigated the connections
between various factors that had an effect on the characteristics of a geopolymer that
was based on fly ash. Specifically, they were interested in determining how the
characteristics of the geopolymer were affected by the various factors. To be more
specific, scientists were interested in understanding how the properties of the
geopolymer were influenced by the myriad of circumstances. To be more precise, the
scientists wanted to see how the multiplicity of situations altered the characteristics of
the geopolymer, and they were interested in understanding how this happened. They
made the discovery that the properties of the geopolymer were altered as a result of the
fact that the components that went into the process of geopolymerization were not
completely dissolved before the process began. This caused the characteristics of the
geopolymer to be altered in a way that was unexpected by them. It was shown that this
has an effect on the properties of the geopolymer. [Citation needed] The quantity of
water that was present, the amount of time that it was allowed to cure for, and the
temperature that it was allowed to cure at all had an effect on the properties of the
geopolymer. These were only some of the other aspects that had an effect. Both the
environment in which the material was cured and the temperature at which it was
calcined had an effect on the compressive strength of the finished product. After being
subjected to the curing process for twenty-four hours at a temperature of seventy-five
degrees Celsius, it was discovered that the samples' compressive strength had greatly
increased. As a direct result of the fact that the curing process had to be carried out

19. 10
over a much-extended length of time, the compressive strength of the material was
negatively affected.
2.3 Use of Fly Ash in Concrete
In the past, fly ash was used in the construction of concrete as a partial replacement for
Portland cement. This was done in order to save money. This was done in an effort to
reduce financial costs. This was done in an attempt to cut down on the monetary
expenditures. The development of high volume fly ash (HVFA) concrete is a
significant achievement in this sector of the construction industry. Despite the fact that
it contains up to 60% fly ash, this type of concrete has extraordinary mechanical
capabilities and outperforms traditional concrete in terms of durability. High volume
fly ash concrete is yet another name for high volume fly ash concrete. HVFA concrete
is an abbreviation that is sometimes used to refer to this kind of concrete. The results
of the tests suggest that concrete produced with HVFA may have a longer lifetime
than concrete produced using Portland cement (Malhotra 2002).
Recently, a research group from Montana State University in the United States
determined, through the use of field testing, that Portland cement can be replaced with
100 percent high-calcium (ASTM Class C) fly ash in the production of concrete. This
was accomplished by replacing the Portland cement with fly ash. The United States of
America served as the location for the study. The governmental organisation was
responsible for completing this task. This objective was achieved with fantastic
results. The production of a significant amount of fly ash concrete was made feasible
by the use of technology that was developed specifically for the production of ready-
mixed concrete. The findings of the field testing indicate that freshly mixed concrete
may be transported, unloaded, placed, and finished with a minimum of difficulty
(Cross et al., 2005).
2.4 Fly Ash-Based Geopolymer Concrete
In the past, there hasn't been a whole lot of research carried out on reinforced geopolymer
concrete members that are founded on fly ash. Palomo et al. (2004) investigated the
mechanical characteristics of geopolymer concrete that was based on fly ash. Their
findings were published in the journal Construction and Building Materials. It was found

20. 10
that the curing techniques, notably the curing time and temperature, had a significant
impact on the characteristics of the material. This was especially true for the temperature.
In addition to this, a limited number of tests were done on specimens made of reinforced
geopolymer concrete sleepers. This fact was also stated in their research. Brooke et al.
conducted an additional study, which looked at the possibility of using geopolymer
concrete in the process of constructing structural components (2005). It was discovered
that the behaviour of beam-column joints constructed using geopolymer concrete was
similar to that of members made of Portland cement concrete.
Research on fly ash-based geopolymer concrete was carried out at Curtin University, and
the results of that research are detailed in Research Reports GC1 and GC2 (Hardjito and
Rangan 2005, Wallah and Rangan 2006), in addition to other publications that can be
found in the References section at the end of this Report.

21. 10
CHAPTER 3
SPECIMEN MANUFACTURE AND TEST PROGRAM
3.1 Introduction
In addition to giving information about the testing programme that is presently
being carried out, this chapter outlines how the test specimens themselves are
created and explains how the process works. In all, there were twenty-four
reinforced geopolymer concrete beams and twenty-four reinforced geopolymer
concrete columns that were subjected to the procedures of production and testing.
The criteria of the test were designed to include a range of values representative of
those that are often encountered in the real world. The capacities of the various
pieces of testing equipment that were available in the laboratory served as a
primary source of information for the evaluations that were performed about the
dimensions of the test specimens. Both the tensile reinforcement ratio and the
compressive strength of the concrete served as the test parameters for the beam
specimens. The load eccentricity, the ratio of longitudinal reinforcement, and the
compressive strength of the concrete were the test parameters for the column
specimens. The test was designed to determine which of these factors was most
important.
3.2 Structural Beams
3.2.1 Materials in Geopolymer Concrete
3.2.1.1 Fly Ash
The provided the low-calcium dry fly ash that was used in this investigation; the ash
was given an ASTM Class F classification. The investigation relied heavily on this ash
as its principal source of material.
Table 3.1 provides for your review the results of an X-ray fluorescence (XRF) analysis
that was performed on the sample. This table contains information on the numerous
chemical components that may be discovered in fly ash. The components are broken

22. 10
down into their respective categories. The XRF analysis was conducted by the
Department of Applied Chemistry at the college.
Table 3.1 Chemical Composition of Fly Ash (mass %)
Figure 3.1 illustrates the particle size distribution of the fly ash that was collected and
may be seen by interested parties. Figure 3.1 presents the size distribution as a
percentage of volume in graph A, while graph B of the same figure presents the
cumulative size distribution as a percentage of volume. Both graphs are included in
the same figure. Both graphs are shown within the same figure as one another (passing
size). The organisation that carried out the particle size study of the fly ash was the
CSIRO-Division of Minerals (Particle Analysis Services).
Figure 3.1 Particle Size Distribution of Fly Ash

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3.2.1.2 Alkaline Solutions
In order to accomplish a reaction with the aluminium and the silica that were present
in the fly ash, a mixture of sodium silicate solution and sodium hydroxide solution
was used. This was done in order to get the desired result. This action was taken in
order to achieve the aimed-for outcome.
The sodium silicate solution was acquired in sizeable quantities from a source that was
situated in the immediate vicinity of the immediate area. It included sodium oxide at a
mass percentage of 14.7%, silicon dioxide at a mass percentage of 29.4%, and water at
a mass percentage of 55.9%. To manufacture the solution, pellets of commercial-grade
sodium hydroxide with a purity level of 97 percent were dissolved in water to make
the solution. This was done so that the solution could be prepared. A nearby retailer
provided access to a significant supply of pellets, which were subsequently purchased
by the company. Regarding the beams, it was discovered that the sodium hydroxide
solution had a concentration of 14 molars. In order to achieve this level of
concentration, one litre of the solution contains 14 times 40, which is equivalent to
560 grammes of pelletized sodium hydroxide. This level of concentration is achieved
by adding pelletized sodium hydroxide. The solution was pelletized sodium hydroxide
in order to reach this level of concentration, which was reached by adding it. On the
basis of the findings of laboratory tests, it was determined that water made up 59.6
percent of the total mass of the combination, while sodium hydroxide pellets made up
only 40.4 percent of the solution. It was essential that at the very least one day pass
between the time that the alkaline solutions were created and the time that they were
utilised. This was a requirement that had to be adhered to.

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3.2.1.3 Super Plasticizer
They provided a super plasticiser that was based on sulphonated naphthalene in order
to increase the fresh concrete's workability. This plasticizer was used to improve the
fresh concrete's workability. It was used with the aim of raising the fresh concrete's
workability.
3.2.1.4 Aggregates
In addition to fine sand, the aggregates that were used came in a total of three different
sizes, the smallest of which measured 10 millimetres and the largest of which was 7
millimetres. The building project made use of the biggest aggregates that could be
found. All of the aggregates were in a state that is known as saturated surface dry
(SSD), and they had all been treated to fulfil the standards that are outlined in the
applicable Indian Guidelines AS 1141.5-2000 and AS 1141.6-2000.
The grading combination of the aggregates is one that fulfils the conditions given by
the British Standard BS 882:1992, which was published in the same year it was first
made available. A fineness modulus of 4.5 was determined to exist among the
aggregates after they were combined with one another. The following table, which
may be seen below, provides an overview of the many grade combinations that can be
achieved using the aggregates.
Table 3.2 Grading Combination of Aggregates

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3.2.2 Mixture Proportions of Geopolymer Concrete
The results of the experiments, which served as the foundation for the development of
the combination proportions, have been documented in Research Report GC1, which
may be accessed by clicking on this link. Anytime, wherever, you can have access to
these results (Hardjito and Rangan 2005). Before casting the beam specimens, a
number of experimental mixes were prepared and put through a battery of tests to
ensure that the results would be consistent. This was done to ensure that the findings
could be replicated. This was done before the casting of the beam specimens so that
they could be properly analysed.
It was found that there are three different combinations that, depending on which one
is chosen, may yield nominal compressive strengths of either 40, 50, or 75 MPa. These
strengths are determined by the amount of pressure that can be applied to the material.
The results of this investigation led to the establishment of these ideals. These three
distinct permutations are referred to by the corresponding letters GBI, GBII, and
GBIII in the notation system. The results of the many different permutations that were
evaluated are shown in Table 3.3, along with precise information on each
combination. The amount of extra water that was added during the blending process,
which was the same for all of the three different combinations, is the only thing that
can be seen to be different between the three different combinations.
Table 3.3 Mixture Proportions of Geopolymer Concrete for Beams
3.2.3 Reinforcing Bars
Four different sizes of deformed steel bars (N-bars) were used as the longitudinal

26. 10
reinforcement. Samples of steel bars were tested in the laboratory. The results of
these tests are given in Table 3.4.
Table 3.4 Steel Reinforcement Properties
3.2.4 Geometry and Reinforcement Configuration
All of the beams had a cross-section that was three hundred millimetres wide and two
hundred millimetres deep; their length was three thousand three hundred millimetres; and
they were simply supported across a distance of three thousand millimetres. The beams
were designed to fail in a flexural manner as their intended mechanism of failure. This
structure used four different tensile reinforcement ratios in order to get the desired results.
A see-through cover was located on each of the faces, and it was spaced 25 millimetres
away from the reinforcement. The form of the beams as well as the reinforcing features are
shown in Figure 3.2, and the information on the specimens can be found in Table 3.5.

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Figure 3.2 Beam Geometry and Reinforcement Details
Table 3.5 Beam Details
Series Beam Beam
Reinforcement Tensile
Dimensions
(mm) Compression Tension
Reinforcement
ratio (%)
1 GBI-1 200x300x3300 2N12 3N12 0.64
GBI-2 200x300x3300 2N12 3N16 1.18
GBI-3 200x300x3300 2N12 3N20 1.84
GBI-4 200x300x3300 2N12 3N24 2.69
2 GBII-1 200x300x3300 2N12 3N12 0.64
GBII-2 200x300x3300 2N12 3N16 1.18
GBII-3 200x300x3300 2N12 3N20 1.84
GBII-4 200x300x3300 2N12 3N24 2.69
3 GBIII-1 200x300x3300 2N12 3N12 0.64
GBIII-2 200x300x3300 2N12 3N16 1.18
GBIII-3 200x300x3300 2N12 3N20 1.84
GBIII-4 200x300x3300 2N12 3N24 2.69

28. 10
3.2.5 Specimen Manufacture and Curing Process
In the beginning, the coarse aggregates and the sand that was in a saturated surface dry
condition were combined with the fly ash and mixed for approximately three minutes in
a laboratory pan mixer that had a capacity of 80 litres. This was done in order to ensure
that the fly ash was evenly distributed throughout the mixture. Following the
completion of the first phase of mixing, the alkaline solutions, the super plasticizer, and
the supplementary amount of water were added to the components that were dry. After
that, we gave the mixture an additional period of time, which was a total of four
minutes.
Figure 3.3 Moulds with Reinforcement Cages
Fresh concrete was poured into the moulds as soon as the ingredients were well combined,
which was immediately followed by the mixing of the other ingredients. Every single one of
the beams was made by horizontally casting two layers of wood in moulds made of wood.
This process was repeated for each and every beam. Throughout the process of packing each
layer down prior to its being crushed, stick internal compacters were used as packing tools.
Due to the restricted capacity of the laboratory mixer, casting two beams required a total of
six separate batches in order to be completed. Alongside each batch, cylinders were cast that
had a height of two hundred millimetres, a diameter of one hundred millimetres, and a
diameter of two hundred millimetres. On the same day that these cylinders were subjected to

29. 10
the beam testing, they were further subjected to the compression test. It was necessary to
conduct individual slump tests on each and every new batch of concrete in order to get an
accurate evaluation of the mix's quality. This was necessary in order to ensure that the mixes
were of the highest possible standard. Not only do these drawings depict the moulds with the
reinforcing cages (as shown in Figure 3.3), but they also show the process of compacting the
material (shown in Figure 3.4)
Figure 3.4 Beam Compaction
Following the conclusion of the casting procedure, each specimen was allowed to rest at room
temperature for a total of three days. It has been shown that increasing the amount of time that
concrete is allowed to cure over longer spans of time results in an improvement in the material's
ability to withstand compression (Hardjito and Rangan, 2005). After the three days had passed, the
specimens were put into the steam-curing chamber (Figure 3.5), where they stayed for an
additional day to be cured at a temperature of sixty degrees Celsius. This process was repeated
once more.

30. 10
Figure 3.5 Curing Chamber
As part of the boiler installation system, a thermocouple and a solenoid valve were installed in the
steam-curing chamber. These components were included so that the temperature in the chamber
could be maintained at a consistent level. In addition to that, a digital temperature controller was
also attached to the system in each of its components (Figure 3.6). The computerised controller
manually opened the solenoid valve in order to deliver the steam; but, after the chamber had
attained the correct temperature, it closed the valve automatically. Condensation on the concrete
was something that was to be avoided at all costs, so in order to do so, a covering made of plastic
was placed as a layer of protection over the top of the concrete before it was allowed to set.
After the curing process had been completed, the beams and the cylinders were removed from the
chamber and allowed to air-dry at ambient temperature for a further twenty-four hours before being
demoulded. This was carried out before the beams and cylinders were put into operation. After that,
the test specimens, which are shown in Figure 3.7, were left in the natural settings of the laboratory
until the day of the tests. The graphic provides a visual representation of these configurations.
Throughout the duration of that time period, the temperature in the laboratory ranged anywhere
from 25 to 35 degrees Celsius, depending on the exact time of day.

31. 10
Figure 3.6 Steam Boiler System
Figure 3.7 Beams after Demolding

32. 10
3.2.6 Test Set-up and Instrumentation
The capacity of each beam was determined by using a universal test machine that has
a capacity of 2500 kN, and the following findings were discovered as a consequence
of this evaluation: Simply keeping the beams at a distance of three thousand
millimetres was all that was required (mm). The span was weighted down by two
concentrated loads that were set in a symmetrical way throughout its length. These
weights were placed on each side of the beams. There was a space of one metre and
one hundred and fifty millimetres between each of the loads. Figures 3.8 and 3.9,
respectively, provide a visual representation of the setup that will be applied to the
assessment later on.
Figure 3.8 Arrangement for Beam Tests
During the process of the assessment, a digital data collection device was used so that all of the
information that was obtained could be compiled. Linear Variable Data Transformers, more
often abbreviated to LVDTs for convenience, were used in order to measure the beam's
deflections at a number of different sites spread out along its length. These places included the
very beginning as well as the very end of the beam. Every single LVDT went through the
process of being calibrated before any tests were carried out. It was discovered that there was a
linear link between the output of the LVDTs, which was measured in millivolts (mV), and the
actual movement, which was measured in millimetres. Experimentation led to the discovery of
this fact (mm).

33. 10
The procedure of calibrating the LVDTs requires the use of a milling machine in order to be
completed successfully. The movement of the LVDTs was measured using a dial gauge, which
was mounted to the milling machine and used to secure the LVDTs. Additionally, the dial
gauge was used to monitor the movement of the LVDTs. This number was connected to the
amount of change in the dial gauge, which was measured in millimetres, and the output of the
movement of the LVDT was represented in millivolts (mV). Monitoring the amount of
movement in the LVDT was accomplished with the help of the dial gauge. The values that
were obtained from the LVDTs were converted from millivolts to millimetres by the use of
these measures.
3.2.7 Test Procedure
Before the specimens were placed into the machine, the beam surfaces at the points where
the supports and loads were going to be ground down to a smooth finish in preparation for
the loading of the specimens. This was done in order to eliminate any potential unevenness
that may have been there. A white wash was given to the surface of each specimen so that
any fractures, if they were there, would be easier to observe. This was done so that the
fractures could be more easily seen.
During the course of the method, the tests were carried out by ensuring that the movement
of the test machine platen maintained a pace of 0.5 millimetres per minute throughout the
whole process. Because of this, we knew that the findings of the tests could be trusted.
There was no consistent pattern to the number of samples that were gathered at a pace
ranging from ten to one hundred per second. Samples were obtained at a rate of one per
second. When the test beam was getting close to the intended peak load, a higher rate was
employed so that sufficient data could be acquired to trace the load-deflection curve close
to the point of failure. This was done in order to ensure that the beam would not fail before
reaching the expected peak load. It was necessary to do this in order to guarantee that the
beam would not break prior to reaching the anticipated peak load. This was done to
guarantee that enough quantities of information were acquired, so that's why it was done.
In order to monitor the beam's deflection, linear variable differential transducers (LVDTs)
were embedded at strategic locations throughout its length at varying intervals. This was
done to check that the information was correct. After the integrity of the whole system had
been verified, the initial readings on the data collection system were cleared to zero in

34. 10
preparation for the application of the load. This was accomplished prior to the load being
applied.
For each test beam, data was collected for the portions of the load-deflection curve that
corresponded to the hardening (steepening) and flattening (hardening) of the curve. These
portions of the curve were referred to as the steepening and flattening, respectively. The
measurement of the softening section (which occurred after the peak load) was continued
until one of two things happened: either the limit of LVDT movement at mid-span was
achieved, or the data logger was unable to record any more information since the specimen
had completely failed. The measurement of the softening section was regarded as finished
after the limit of LVDT travel at mid-span had been achieved.

35. 10
Figure 3.9 Beam Test Set-up
3.2.8 Properties of Concrete
In order to conduct the slump test (Figure 3.10) and to cast 100mm x 200mm cylinders
for the compressive strength test, samples of freshly mixed concrete were taken from
each batch and stored away until they were needed. This allowed the tests to be carried
out successfully. Casting cylinders was a requirement for each of these tests. The results
of the slump tests showed that there was consistency throughout all of the different
batches of concrete that were prepared using the many distinct combinations. This was

36. 10
discovered by the findings that were obtained from the testing. Table 3.6, which
provides a summary of the data, includes a comparison of the slump levels that are
experienced on average by each series.
Figure 3.10 Slump Test of Fresh Concrete
All test cylinders were compacted and cured in the same manner as the beams, and
tested for compressive strength when the beams were tested. At least three cylinders
were made from each batch of fresh concrete. The test data indicated that the
compressive strength of cylinders from various batches of concrete were consistent.
The average cylinder compressive strengths of concrete are given in Table 3.6,
together with the average density of hardened concrete.

37. 10
Table 3.6 Properties of Concrete
strength (MPa)
3.3 Columns
3.3.1 Materials in Geopolymer Concrete
3.3.1.1 Fly Ash
The foundation material contained low-calcium (ASTM Class F) dry fly ash that was obtained
from the Colli Power Plant in the state of Western Australia. This ash was used in a manner
that was comparable to that of the beams. The foundation was built with ash like this, which
was employed in the building. It is important to note that the batch of fly ash that was used for
the beams was different from the batch that was used for the columns of the structure. An X-ray
fluorescence (XRF) analysis was carried out in order to identify the chemical components of
the fly ash. The results of this analysis are summarised in Table 3.7, which can be found further
down on this page. The particle size distribution of the fly ash is shown in Figure 3.11, which
provides evidence of this fact.
Table 3.7 Chemical Composition of Fly Ash (mass %)
Concrete Density
Series Beam
Slump
(mm)
compressive (kg/m3
)
I GPC-1 255 37 2237
GPC-2 254 42 2257
GPC-3 254 42 2257
GPC-4 255 37 2237
II GPCI-1 235 46 2213
GPCI-2 220 53 2226
GPCI-3 220 53 2226
GPCI-4 235 46 2213
III GPCII-1 175 76 2333
GPCII-2 185 72 2276
GPCII-3 185 72 2276
GPCII-4 175 76 2333

38. 10
Figure 3.11 Particle Size Distribution of Fly Ash
3.3.1.2 Alkaline Solutions
Beams that used alkaline solutions were created in the same manner as they were when
dealing with alkaline solutions; specifically, sodium hydroxide solution and sodium
silicate solution were used as the primary components (Section 3.2.1.2). In order to
produce a solution with a concentration of either 16 or 14 moles, flakes of analytical
grade sodium hydroxide (NaOH) were dissolved in water. This step was necessary in
order to manufacture the solution. The NaOH was tested and found to have a purity level
of 98 percent. This made it feasible to make a solution with a concentration of either 16
or 14 molars, depending on what was required. This made it possible to produce a
solution with a concentration of either 16 or 14 molars. It was discovered that flakes of
sodium hydroxide with a total weight of 640 grammes were present in a solution of
sodium hydroxide that had a volume of one litre and a concentration of 16 molars. The
concentration of the solution was measured in moles. The following is a breakdown of
this solution's mass percent, according to the results that were drawn from a number of
different tests that were carried out in a laboratory: The amount of the whole that was
comprised of NaOH flakes was 44.4 percent, while the amount that was comprised of
water was 55.6 percent. The information that was supplied before in Section 3.2.1.2 on
the solution that has a concentration of 14 molars has not been updated since it was
initially put down. This information has been there since it was published for the first
time in that section. At the very least, one day before the sodium silicate solution was
used, another solution containing sodium hydroxide (NaOH) was added to it. This second
solution was added to the sodium silicate solution. The initial answer was improved by
including this additional solution. The components of the solution of sodium silicate are
as follows: 14.7 percent sodium oxide, 29.4% silicon dioxide, and 55.9% water

39. 10
3.3.1.3 Super Plasticizer
As for the beams (Section 3.2.1.3), a sulphonated-naphthalene based super plasticiser
was used.
3.3.1.4 Aggregates
Three types of locally available aggregates comprising 10mm and 7mm coarse
aggregates, and fine sand were used. The fineness modulus of combined aggregates
was 4.50. The aggregate grading combination is shown in Table 3.8
Table 3.8 Grading Combination of Aggregates
3.3.2 Mixture Proportions of Geopolymer Concrete
Table 3.9 provides further information on the proportions of the geopolymer concrete
mixture that were used in the manufacturing of the column specimens. These proportions
were used while the column specimens were being created. The average compressive
strength of mixes GCI and GCII was predicted to be forty megapascals (MPa), while
combinations GCIII and GCIV were predicted to be sixty megapascals (MPa).

40. 10
Table 3.9 Mixture Proportions of Geopolymer Concrete for Columns
Column series

41. 10
3.3.3 Reinforcing Bars
When constructing the column, N12 deformed bars were included into the process with the aim
of providing additional longitudinal reinforcement. In order to accomplish the task of providing
lateral reinforcement, plain wires that had been hard-drawn were used. These wires had a
diameter of 6 millimetres. One single piece of testing equipment was used on all three different
bar samples that were used for the tension tests. These tests were carried out on the bar samples
in order to determine their resistance to tension. You are welcome to have a look at Table 3.10,
which provides an overview of the qualities that steel reinforcement has.
Table 3.10 Steel Reinforcement Properties
3.3.4 Geometry and Reinforcement Configuration
Each column had a total length of 1500 millimetres, and one side of each column measured
175 millimetres. As a kind of longitudinal reinforcement, the first six columns each had
four deformed bars measuring 12 millimetres placed into them, whilst the last six columns
each had eight deformed bars measuring 12 millimetres inserted into them. In contrast to
this, the first six columns each had just four distorted bars measuring 12 millimetres placed
into them. This remained the case for the rest of the columns. The accomplishment of
reinforcement ratios of 1.47 percent and 2.95 percent, respectively, was made possible as a
result of these arrangements. A concrete cover measuring fifteen millimetres in depth was
poured and then placed between the longitudinal bars and each face of the column. This
cover was then positioned in the middle of the longitudinal bars. Figure 3.12, which may
be seen on this page, also provides an illustration of the column's overall design as well as
its reinforcing characteristics. You may get the information that Table 3.11 includes on the
columns by clicking here.
When the length of the test columns was effectively determined, it was found to be 1684
millimetres when measured from the centre to the centre of the load knife edges. This was
because the end assemblies were attached to both of the test columns' ends at the same time

42. 10
(for further information, see Section 3.3.6)
Figure 3.12 Column Geometry and Reinforcement Details

43. 10
Table 3.11 Column Details
3.3.5 Specimen Manufacture and Curing Process
When examined, both the sand and the coarse aggregates were in a condition that is known
as saturated surface dry. At the outset, the aggregates and the dry fly ash were put into a
pan mixer and mixed together for close to three minutes. After the alkaline solutions and
additional water were mixed together in a separate container and stirred, the mixture was
transferred to the container that contained the solid particles, and then the alkaline
solutions and additional water were added to the mixture after it had been stirred. In order
to ensure that the wet components were well incorporated after each addition throughout
the baking process, an extra four minutes of mixing time was required.
After the components of the concrete mixture had been meticulously brought together and
completely mingled, the freshly mixed concrete was poured into the moulds as rapidly as
humanly feasible. In order to create each column, three layers of concrete were poured in a
horizontal pattern into wooden moulds. The columns were produced using this method as
the manufacturing process. After being physically crushed with the use of a rod bar, each
layer was then shaken for a period of thirty seconds on a table that was fitted with a
mechanism for vibrating. This was done in order to ensure that the material had been
thoroughly broken up. This was done in order to guarantee that the material was
fragmented into its smallest possible pieces. In addition, a number of cylindrical moulds

44. 10
with a diameter of one hundred millimetres and a height of two hundred millimetres were
produced using each combination. These moulds had a height of two hundred millimetres
and a diameter of one hundred millimetres. These moulds measured two hundred
millimetres in height and one hundred millimetres in diameter at their widest point. Figure
3.13 illustrates how the vibrating table is readied for use by setting the column cages and
moulds in the suitable places. This allows the table to be put into action.
Figure 3.13 Moulds and Column Cages
As soon as the casting process was completed, the GC-I and GC-II column series, together with
the cylinders, were positioned inside of a steam-curing chamber and exposed to a temperature of
sixty degrees Celsius for a period of twenty-four hours. This process was repeated twice. After
being stored at ambient temperature for three days, the specimens from the GC-III and GC-IV
series were transferred to the steam-curing chamber, where they were heated to a temperature of
sixty degrees Celsius for a period of twenty-four hours. The procedure that was utilised to cure
the concrete was quite similar to the one that was used to cure the beams, so the two processes
were pretty much interchangeable. Condensation on the concrete was something that was to be
avoided at all costs, so in order to do so, a covering made of plastic was placed as a layer of
protection over the top of the concrete before it was allowed to set.

45. 10
After the curing process was complete, the columns and cylinders were removed from the
chamber and allowed to air-dry at ambient temperature for a further twenty-four hours before
being demoulded. This task had to be completed before the columns and cylinders could be used.
After that, the test specimens were stored in the laboratory until the day of the testing at
temperatures and humidity levels that were described as being ambient (Figure 3.14).
Throughout the duration of that time period, the temperature in the laboratory ranged anywhere
from 25 to 35 degrees Celsius, depending on the exact time of day.
Figure 3.14 Columns after Demoulding
3.3.6 Test Set-up and Instrumentation
After putting each column through its paces in a universal test machine with a capacity of
2500 kN for force bearing, the findings were analysed to determine the strength and
durability of each column. Each end of the columns had a pair of specialised end
assemblages that might be found there. These assemblages had been put together inside the
confines of the company itself. The end assemblies were constructed in such a manner
throughout the course of the technique for testing so that the column could be positioned
appropriately to the specified load eccentricity at each phase of loading (Kilpatrick, 1996).

46. 10
The thickness of all of the steel plates that were used in the building of the completed
components was forty millimetres, and each of the components required the use of three
steel plates for its construction. The testing machine had foundation plates that were
securely fastened to both the machine's top and bottom platens. Throughout the duration of
the testing procedure, the end assemblies were kept in a consistent position by using these
base plates as necessary. Because each of the male plates had a male knife-edge that could
be placed into a female plate, it was possible to utilise the male plates with female plates
that also had female knife-edges. This was made possible by the fact that the female plates
also have female knife-edges. As a result, it became feasible to combine the male and
female plates in use. In order to reduce the amount of friction that would take place
between the two surfaces, the pointed tips of the knife edges were rounded off, and a
smooth finish was applied to them. This was done in preparation for use. The adapter plate
was able to withstand a wide variety of load eccentricities, the measures of which spanned
from 0 to 65 millimetres, since it had a number of holes that were separated from one
another by a distance of 5 millimetres. The male and female plates remained in the same
position with respect to the platen of the testing equipment after the end assembly had been
installed on the testing equipment. This was the case even though the end assembly had
been moved. Even after the end assembly had been fastened into position, this continued to
be the situation. The particulars of the ruling in its entirety and entirety.

47. 10
Figure 3.15 Section View of the End Assemblage
Test Column
Figure 3.16 Plan View of the End Assemblage
During prior testing on columns that was carried out at Curtin, the hinge support circumstances
at column ends were efficiently reproduced by the end assembly, which successfully duplicated
such conditions in a successful manner. To put it another way, the final assembly was able to
effectively simulate the conditions. The steel end caps that were situated on both sides of the test
column and were fastened to the end assembly units at the column's ends were able to prevent
the end zones of the test column from failing, thus preventing the failure of the test. Because of
this, the end zones of the test column did not wind up failing as a result of their failure. Figure
3.17 depicts the whole architecture of the finished assembly in its entirety, which may be viewed
in its entirety.

48. 10
Figure 3.17 End Assemblage Arrangement for Column Tests
During the course of the test, automated data collection equipment was employed in order to
capture all of the relevant data that was necessary to be gathered. After undergoing the necessary
adjustments, a total of six Linear Variable Differential Transformers (LVDTs) were put to
productive use after being calibrated in the right manner. In order to achieve a precise
measurement of the deflections that took place throughout the whole length of the test column,
five LVDTs were positioned in strategic areas along the tension face of the column. This allowed
for the correct measurement of the deflections that took place. In the course of the testing, an
LVDT was fixed to the perpendicular face in order to track the movement of the columns in a

49. 10
direction that was perpendicular to the plane of the test. This was done in order to guarantee that
the columns would stay in the locations that had been planned for them.
3.3.7 Test Procedure
Before the specimen was placed into the end assembly, the column ends were sanded
down to give a smooth surface. This was done in preparation for the end assembly. This
was done in advance of the installation of the specimen in preparation for it. This was
done in order to prevent any discrepancies in loads that may have been induced by the
uneven surfaces. This was done in order to avoid any inconsistencies in loads. Before
installing the column in the machine, it was necessary to make the appropriate
adjustments to the end components of the column in order to achieve the desired load
eccentricity. This concern was addressed and resolved before the column was loaded into
the machine. This line served as a portrayal of the eccentricity of the load, which was
symbolised by the line that went through the centre of the axes of the knife blades.
Additionally, this line indicated the eccentricity of the load (Figure 3.17).
This stage needed to be finished first in order for the base plates of the machine to be able
to be attached to the top and bottom plates of the machine. After that, the female plate
was secured to the base plate using the female knife-edge that was already a part of the
female plate, and the male knife-edge was then joined to the female plate using the male
plate. The role of the support for the female plate was fulfilled by the base plate. After
completing this part of the process, the female plate was attached to the foundation plate
using screws. After that, the specimen was placed inside of the bottom end cover, which
would finally function as its permanent slumbering spot. After making sure that the
specimen was positioned correctly within the bottom end arrangement, the plates of the
testing machine were moved upward until the top of the column was positioned correctly
within the top end cap. This was done after making sure that the specimen was positioned
correctly within the bottom end arrangement. This step was taken after confirming that
the specimen was positioned correctly inside the bottom end arrangement. This step had
to be completed before we could go on to the next one in the procedure. Before beginning
the procedure of measuring the specimen, a preload of 20 kN was applied to it. This was
done before the operation began. Even after the process of measuring the specimen had
started, this step was taken to ensure that the column axes would continue to be aligned in
the same plane as the knife-edge axes. This was done to assure accuracy. After the
column had been positioned where it needed to be, the necessary movable steel plates

50. 10
were put in place. After that, in the last phase, they were firmly fastened between the steel
end cap and the column.
LVDTs were installed in key locations throughout the structure so that the lateral
movement of the column could be tracked. The specimens were subjected to an axial
compression test, during which the specimens' compressive strength was permitted to
gradually increase over the course of the test while the load eccentricity was carefully
monitored and controlled. Throughout the course of the experiment, observations were
made at various points. It was determined that the maximum allowable rate of travel for
the controlled movement of the bottom platen of the testing machine is 0.3 millimetres
per minute. This was the result of the research that was conducted. This was the fastest
speed at which you were permitted to go. This restriction on the maximum allowed speed
has been implemented. You are more than welcome to have a look at the column that has
been made ready for testing and is shown in Figure 3.18 right here on this website.

51. 10
Figure 3.18 Column in the Test Machine
There was no consistent pattern to the number of samples that were gathered at a pace ranging
from ten to one hundred per second. Samples were obtained at a rate of one per second. When
the projected peak load of the test column was getting closer, a higher rate was utilised so that
sufficient data could be acquired to trace the load-deflection curve toward the peak load. This
was done in order to determine whether or not the test column would fail. This was done so that
we could evaluate whether or not the test column would be able to sustain the load that was

52. 10
being applied to it. This was done to guarantee that enough quantities of information were
acquired, so that's why it was done. The load-deflection curve was constructed for each test
column, and its steepening (hardening) and softening (steepening) parts were analysed to
determine their respective locations. This was done so that the relative positions of the two
could be determined.
The measurement of the softening part (after peak load) continued until either the limit of
LVDT travel at mid-height was reached or the deflected column approached the rotation limit
of knife-edges. If the limit of LVDT travel at mid-height was reached, then the measurement of
the softening part was completed. Once the LVDT travel limit at mid-height was achieved, the
measurement of the softening section was considered to be finished. After reaching the upper
limit of the LVDT's movement at the mid-height position, it was determined that the
measurement of the softening portion was complete.
3.3.8 Concrete Properties and Load Eccentricities
During the process of casting the columns, representative samples of concrete were
taken from the mixer in order to conduct a slump test and to cast 100 mm x 200 mm
cylinders in order to conduct a compressive strength test. Both of these tests were
carried out in order to ensure that the columns would have adequate strength. Both of
these experiments were carried out during the time when these columns were being
cast. These tests were carried out just at the same time as the columns were being cast.
Casting, compacting, and curing were the techniques that were used for the cylinders,
and they were exactly the same as the casting and curing methods that were used for
the test columns. They were checked on the day when the accuracy of the columns
was assessed, which means that they were examined on the same day. Table 3.12
displays the typical range of values for the slump of new concrete, as well as the
compressive strength and density of concrete after it has been allowed to set.
It is necessary to adjust the adopter plates of the end assemblies to the appropriate
values before attempting to achieve the load eccentricity that is required. This makes it
possible to acquire the load eccentricity that is desired. Table 3.12 contains this data in
addition to the others it contains.

53. 10
Table 3.12 Load Eccentricity and Concrete Properties

54. 10
CHAPTER 4
PRESENTATION AND DISCUSSION OF TEST RESULTS
4.1 Introduction
The results of an experimental programme that was carried out on geopolymer reinforced
concrete beams and columns are presented in this chapter. Not only does it describe the
behaviour, but it also explains the fracture patterns, the failure processes, as well as the
load-deflection properties of the material. It is also discussed how the tensile strength of
beams and columns is impacted by a variety of characteristics, as well as how those
characteristics may either positively or negatively influence the tensile strength.
4.2 Beams
4.2.1 General Behaviour of Beams
The specimens were put through a series of tests in which the weight was incrementally
increased until they were unable to continue withstanding it and broke. As the load
continued to build, the spans of the beams started to develop fractures called flexural cracks,
and the beams themselves started to deform as a direct consequence of the strain. In the end,
the normal flexure mode led each and every beam to disassemble into its component pieces.
This was the result of the beams breaking apart.
Figure 4.1 depicts a hypothetical load-deflection curve at the place in the span of the beams
that is taken to represent the beams' midway point. This position is depicted in the middle of
the span. A linear link between the load and the amount of deflection at the middle of the
span is depicted as it is increased while the load is being carried by the structure. This
correlation remains stable even after accounting for a greater load. During the course of the
experiment, there were a significant number of separate occurrences, and the load-deflection
curves provide a graphical representation of each and every one of these events. The events
that are identified here are the initial cracking (A), the yielding of the tensile reinforcement
(B), the crushing of concrete at the compression face associated with spalling of concrete
cover (C), a slight drop in the load following the ultimate load (C'), and the disintegration of
the compression zone concrete as a consequence of buckling of the longitudinal steel in the
compression zone. Each of these events is labelled with an alphabetical letter. The initial
fracture (A), the yielding of the tensile reinforcement (B), and the crushing of concrete at the

55. 10
beginning (C) are the three stages of failure (D). These characteristics are typical of the
behaviour of beams made of reinforced concrete when they are subjected to flexural
circumstances (Warner et al. 1998).
B
C
C’ D
A
O
Deflection
Figure 4.1 Idealized load-deflection Curve at Mid-span
Although the various occurrences shown in Figure 4.1 were not always easily identifiable
in every instance, all of the beams displayed the same behaviour generally. This was the
case since the beams were all made of the same material. Because it was planned for all
of the test beams to have inadequate reinforcement, it is possible to draw the conclusion that
the tensile steel must have reached its yield strength immediately prior to the beams
breaking apart. Later on in this chapter, we are going to talk about the influence that a
number of different elements have on the flexural behaviour of the test beams.
.
4.2.2 Crack Patterns and Failure Mode
In the region of pure bending, flexure fractures started to develop, which was completely
consistent with what was anticipated to happen. Existing fractures propagated over the
Applied
Load

56. 10
span as the load continued to grow, and as the load continued to rise, new cracks
appeared in other locations along the span. As a result of the action of shear force, which
caused these cracks to become angled, some of the flexural fractures that were already
present in the shear span of beams that had a larger tensile reinforcement ratio turned into
inclined cracks. This caused some of the flexural fractures to become angled. As one
travelled the length of the bridge, one could see that the fractures varied in both their
breadth and the distance that separated them from one another. The fracture patterns that
were mentioned in the literature as having been found in reinforced Portland cement
concrete beams were, for the most part, astonishingly similar to the crack patterns that
were identified in reinforced geopolymer concrete beams. These crack patterns were
found to be present in reinforced geopolymer concrete beams.
Cracks that had emerged in the centre of the structure began to grow into massive holes
not long before the bridge entirely collapsed. Because the beams deflected substantially
close to their peak load, it is easy to extrapolate that the tensile steel must have given way
shortly before they collapsed. This may be inferred from the fact that the beams deviated
greatly near their peak load. This may be deduced from the fact that the beams deflected
noticeably when the weight was very near to reaching their maximum capacity. After the
concrete in the compression zone cracked, which was followed by the compressive steel
bars buckling, the beams were unable to keep themselves together for too much longer,
and they finally gave way. The beams had reached their last and most significant stage of
degradation at this point. The failure mechanism exhibited characteristics that are typical
of an under-reinforced concrete beam in their presentation. In particular, the following
are examples of these qualities:
Figure 4.2 illustrates the many failure mechanisms and fracture patterns that were
discovered in the course of testing on a wide range of test beams.

57. 10
GBI-3
GBIII-1
GBIII-2
GBI-2
Figure 4.2 Crack Patterns and Failure Mode of Test Beams

58. 10
4.2.3 Cracking Moment
The load that resulted in the first visible flexural fracture being seen was noted down and
documented. The cracking moments were calculated using this test results as a basis. The
findings are shown in Table 4.1 below.
Table 4.1 Cracking Moment of Test Beams
The link that exists between the cracking moment and the compressive strength of the
concrete in the structure is shown in both Figure 4.3 and Figure 4.4, respectively. Given
the nature of the forecast, it was reasonable to anticipate that there would be a correlation
between the rise in the compressive strength of the concrete and the rise in the cracking
moment. This correlation was found. In addition, the results of the tests revealed that the
effect of longitudinal steel on the cracking moment is almost nonexistent, which was
another interesting discovery (Table 4.1).
The findings of these tests are comparable to those that were found in the investigation of
beams made of reinforced Portland cement concrete.

59. 10
25
20
15
10
5
0
0 20 40 60 80
Concrete Compressive strength (MPa)
Figure 4.3 Effect of Concrete Compressive Strength on Cracking Moment (p
= 0.64% and p = 2.69%)
25
20
15
10
5
0
0 20 40 60 80
Concrete Compressive strength (MPa)
Figure 4.4 Effect of Concrete Compressive Strength on Cracking Moment (p =
1.18% and p = 1.84%)
 = 2.69%
 = 0.64%
 = 1.84%
 = 1.18%
Cracking
Moment
M
cr
(kNm)
Cracking
Moment
M
cr
(kNm)

60. 10
4.2.4 Flexural Capacity
The ultimate moment and the corresponding mid-span deflection of test beams are
given in Table 4.2.
Table 4.2 Flexural Capacity of Test beams
Figure 4.5 depicts the effects that tensile reinforcement has on the flexural capacity of each pair of
beams, and Figures 4.5 through 4.7 continue to exhibit this influence in different ways. These test
trends demonstrate that, as was to be anticipated, there was a large rise in the flexural capacity of
beams together with an increase in the tensile reinforcement ratio. This was the case because of
the combination of the two factors. This was observed in light of the fact that there was also this.
The gain in flexural strength that was seen is about equivalent to the improvement in the tensile
reinforcement ratio that was observed. This is because none of the beams have a sufficient amount
of strengthening material, which is the reason why this is the case.

61. 10
200
175
150
125
100
75
50
25
0
0 0.5 1 1.5 2 2.5 3
Tensile Reinforcement Ratio (%)
Figure 4.5 Effect of Tensile Reinforcement Ratio on the Flexural Capacity of
Beams (GBI Series)
200
175
150
125
100
75
50
25
0
0 0.5 1 1.5 2 2.5 3
Tensile Reinforcement Ratio (%)
Figure 4.6 Effect of Tensile Reinforcement Ratio on the Flexural Capacity of
Beams (GBII Series)
Ultimate
Moment
(kNm)
Ultimate
Moment
(kNm)

62. 10
200
175
150
125
100
75
50
25
0
0 0.5 1 1.5 2 2.5 3
Tensile Reinforcement Ratio (%)
Figure 4.7 Effect of Tensile Reinforcement Ratio on the Flexural Capacity of
Beams (GBIII Series)
The flexural capacity of beams is also influenced by the concrete compressive
strength, as shown by the test data plotted in Figure 4.8. Because the beams are
under-reinforced, the effect of concrete compressive strength on the flexural capacity
is only marginal.
200
180
160
140
120
100
80
60
40
20
0
20 40 60 80 100
Concrete Compressive Strength (MPa)
Figure 4.8 Effect of Concrete Compressive Strength on Flexural Capacity of
Beams
 = 2.69%
 = 1.84%
 = 1.18%
 = 0.64%
Ultimate
Moment
(kNm)
Ultimate
Moment
(kNm)

63. 10
4.2.5 Beam Deflection
The load versus mid-span deflection curves of the test beams are presented in Figure
4.9 to Figure 4.20. Complete test data are given in Appendix A to Appendix C. The
distinct events indicated in Figure 4.1 are marked on the load-deflection curves.
130
120
110
100
90
80
70
60
50
40
30
20
10
0
0 10 20 30 40 50 60 70
Deflection at Mid-span (mm)
Figure 4.9 Load versus Mid-span Deflection of Beam GBI-1
C
C’
B
Load
(kN)

64. 10
180
160
140
120
100
80
60
40
20
0
0 20 40 60 80 100
Deflection at Mid-span (mm)
Figure 4.10 Load versus Mid-span Deflection of Beam GBI-2
260
240
220
200
180
160
140
120
100
80
60
40
20
0
0 10 20 30 40 50 60
Deflection at Mid-span (mm)
Figure 4.11 Load versus Mid-span Deflection of Beam GBI-3
C
B C’
C
B C’
Load
(kN)
Load
(kN)

65. 10
400
350
300
250
200
150
100
50
0
0 10 20 30 40 50 60
Deflection at Mid-span (mm)
Figure 4.12 Load versus Mid-span Deflection of Beam GBI-4
120
110
100
90
80
70
60
50
40
30
20
10
0
0 20 40 60 80 100
Deflection at Mid-span (mm)
Figure 4.13 Load versus Mid-span Deflection of Beam GBII-1
C
B C’
C
B
C’
Load
(kN)
Load
(kN)

66. 10
220
200
180
160
140
120
100
80
60
40
20
0
0 20 40 60 80 100
Deflection at Mid-span (mm)
Figure 4.14 Load versus Mid-span Deflection of Beam GBII-2
260
240
220
200
180
160
140
120
100
80
60
40
20
0
0 10 20 30 40 50 60 70 80
Deflection at Mid-span (mm)
Figure 4.15 Load versus Mid-span Deflection of Beam GBII-3
C
B
C’
B C
C’
Load
(kN)
Load
(kN)

67. 10
360
320
280
240
200
160
120
80
40
0
0 10 20 30 40 50 60
Deflection at Mid-span (mm)
Figure 4.16 Load versus Mid-span Deflection of Beam GBII-4
150
135
120
105
90
75
60
45
30
15
0
0 10 20 30 40 50 60 70 80 90
Deflection at Mid-span (mm)
Figure 4.17 Load versus Mid-span Deflection of Beam GBIII-1
B
C
C’
C
C’
B
Load
(kN)
Load
(kN)

68. 10
200
180
160
140
120
100
80
60
40
20
0
0 10 20 30 40 50 60
Deflection at Mid-span (mm)
Figure 4.18 Load versus Mid-span Deflection of Beam GBIII-2
270
240
210
180
150
120
90
60
30
0
0 10 20 30 40 50 60
Deflection at Mid-span (mm)
Figure 4.19 Load versus Mid-span Deflection of Beam GBIII-3
C
B C’
C
B
C’
Load
(kN)
Load
(kN)

69. 10
400
350
300
250
200
150
100
50
0
0 10 20 30 40 50 60
Deflection at Mid-span (mm)
Figure 4.20 Load versus Mid-span Deflection of Beam GBIII-4
With the assistance of the test findings that are shown in Figures 4.9 to 4.20, we were able to
compute the deflections that occurred at the service load (Ps) and the failure load (Pu). For the
purposes of this investigation, the service load was determined by subtracting 1.5 from Pu. A
summary of the results, including all of their components, may be found in Table 4.3.
Table 4.3 Deflection of Beams at Various Load Levels
Beam
Tensile
Reinforce-
ment ratio
Concrete
Compressive
Strength
Service
Load -Ps
(kN)
2s (mm) Failure
Load -
2u
(mm)
B
C
C’
Load
(kN)
(%) (MPa)
Pu (kN)
GBI-1 0.64 37 75 13.49 112.6 56.63
GBI-2 1.18 42 117 15.27 175.3 46.01
GBI-3 1.84 42 156 13.71 233.7 27.87
GBI-4 2.69 37 217 15.60 325.0 9.22
GBII-1 0.64 46 78 14.25 116.7 54.27
GBII-2 1.18 53 121 14.38 181.1 47.20
GBII-3 1.84 53 159 13.33 238.0 30.01
GBII-4 2.69 46 225 16.16 337.4 27.47
GBIII-1 0.64 76 87 14.10 129.8 69.75
GBIII-2 1.18 72 124 12.55 185.8 40.69
GBIII-3 1.84 72 169 12.38 253.6 34.02
GBIII-4 2.69 76 240 14.88 359.89 35.85

70. 10
4.2.6 Ductility
In this investigation, the ductility of the test beams was analysed by computing the ratio of the
beam's deflection at the time of ultimate stress, which is indicated by the symbol u, to the beam's
deflection at the time of yield stress, which is indicated by the symbol y. This ratio was then
compared to the beam's deflection at the moment of yield stress. After obtaining this ratio, it was
compared to the beam's deflection when it was subjected to its maximum stress. In order to do
this, the elastic theory was used to calculate the yield moment, which may be denoted by the
symbol "My" (Warner et al., 1998). We were able to calculate the deflections that correspond to
My and Mu by analysing the load-deflection test curves that are displayed in Figures 4.9 to 4.20.
These figures illustrate the load-deflection test curves. You may see these numbers farther down
the page. After that, the ductility index d is determined by computing the ratio of the amount of
deflection at the ultimate moment to the amount of deflection at the yield moment. This ratio is
then used to determine the ultimate amount of deflection. This is done so that an accurate
comparison may be made between the ultimate moment deflection and the yield moment
deflection. The ductility index of the test beams is shown in Table 4.4 for your convenience.
Table 4.4 Deflection Ductility of Test Beams
Beam Concrete Ductility Index
Compressive y (mm) u (mm) d = u/y
Strength (MPa)
GBI-1 37 13.59 56.63 4.20
GBI-2 42 15.37 46.01 3.01
GBI-3 42 13.81 27.87 2.03
GBI-4 37 15.60 29.22 1.87
GBII-1 46 14.25 54.27 3.80
GBII-2 53 14.8 47.20 3.28
GBII-3 53 13.33 30.01 2.25
GBII-4 46 16.16 27.47 1.70
GBIII-1 76 14.10 69.75 4.95
GBIII-2 72 12.55 40.69 3.24
GBIII-3 72 12.38 34.02 2.74
GBIII-4 76 14.88 35.85 2.41
Figures 4.21 to 4.23 show the influence of tensile reinforcement on ductility index.
These Figures show that the ductility index decreased as the tensile reinforcement is
increased. The deflection ductility significantly increased for beams with tensile

71. 10
reinforcement ratio less than 2%, whereas the deflection ductility is moderately
unaffected for beams with tensile reinforcement ratio greater than 2%. These test
trends are similar to those observed in the case of reinforced Portland cement
concrete beams (Warner et al 1998).

72. 10
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0 0.5 1 1.5 2 2.5 3
Tensile Reinforcement Ratio (%)
Figure 4.21 Effect of Tensile Reinforcement Ratio on Ductility (GBI Series)
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0 0.5 1 1.5 2 2.5 3
Tensile Reinforcement Ratio (%)
Figure 4.22 Effect of Tensile Reinforcement Ratio on Ductility (GBII Series)
Deflection
ductility
index,

d
Deflection
ductility
index,

d

73. 10
6
5
4
3
2
1
0
0 0.5 1 1.5 2 2.5 3
Tensile Reinforcement Ratio (%)
Figure 4.23 Effect of Tensile Reinforcement Ratio on Ductility (GBIII Series)
4.3 Columns
4.3.1 General Behaviour of Columns
In this investigation, the ductility of the test beams was analysed by
computing the ratio of the beam's deflection at the time of ultimate stress,
which is indicated by the symbol u, to the beam's deflection at the time of
yield stress, which is indicated by the symbol y. This ratio was then
compared to the beam's deflection at the moment of yield stress. After
obtaining this ratio, it was compared to the beam's deflection when it was
subjected to its maximum stress. In order to do this, the elastic theory was
used to calculate the yield moment, which may be denoted by the symbol
"My" (Warner et al., 1998). We were able to calculate the deflections that
correspond to My and Mu by analysing the load-deflection test curves that
are displayed in Figures 4.9 to 4.20. These figures illustrate the load-
deflection test curves. You may see these numbers farther down the page.
Deflection
ductility
index,

d

74. 10
After that, the ductility index d is determined by computing the ratio of the
amount of deflection at the ultimate moment to the amount of deflection at
the yield moment. This ratio is then used to determine the ultimate amount of
deflection. This is done so that an accurate comparison may be made between
the ultimate moment deflection and the yield moment deflection. The
ductility index of the test beams is shown in Table 4.4 for your convenience.
4.3.2 Crack Patterns and Failure Modes
In each and every one of the instances, the fractures first became apparent on
the stress face, somewhere about the middle of the column. Cracks that were previously
present in the columns proceeded to widen as the weight was consistently distributed
throughout their length. As a direct consequence of this, further cracks started to appear
all the way down the length of the columns. The width of the fissures changed
depending on where they were located inside the rock. This caused the width to vary
from one spot to the next. The fissures that were placed at the structure's mid-height
became quite a bit larger as the building was getting closer and closer to collapsing
completely.
Within a range of plus or minus 250 millimetres from the column's centre
height, the failure zone may have been positioned anywhere. The concrete in the
compression zone was broken up, which in the end caused the structure to fall apart and
was the root cause of the failure. Buckling happened in the longitudinal bars of the
columns that were positioned in the compression zone, and this was more visible in the
columns that had been exposed to low eccentricity. Buckling occurred in the
longitudinal bars of the columns that were positioned in the compression zone.
The failure scenarios shown in Figures 4.24 and 4.25 are some of the most
common and likely to occur in test columns. These blunders may be organised into a
great number of different categories.

75. 10
GCI-1 GCIII-1
Figure 4.24 Failure Mode of GCI-1 and GCIII-1

76. 10
GCII-3 GCIV-3
Figure 4.25 Failure Mode of GCII-3 and GCIV-3
4.3.3 Load-Deflection Relationship
Figure 4.26 continues through Figure 4.37 to provide the graph that illustrates
loads in relation to the mid-height deflection of test columns. This graph is viewable in
its entirety here. Appendices A and B, respectively, include the comprehensive findings
of the tests that were conducted. When the columns collapsed, the amount that they bent
in the centre of their heights increased in proportion to the load eccentricity. This was
something that might have been foreseen (Table 4.5).

77. 10
1000
900
800
700
600
500
400
300
200
100
0
0 2 Defle 4 6 8
ction (mm)
Figure 4.26 Load versus Mid-height Deflection Curve (GCI-1)
800
700
600
500
400
300
200
100
0
Figure 4.27
0 2 4 6 8 10 12
Deflection (mm)
Load versus Mid-height Deflection Curve (GCI-2)
Load
(kN)
Load
(kN)

78. 10
600
500
400
300
200
100
0
0 5 10 15
Deflection (mm)
Figure 4.28 Load versus Mid-height Deflection Curve (GCI-3)
1400
1200
1000
800
600
400
200
0
0 2 4 6 8
Deflection (mm)
Figure 4.29 Load versus Mid-height Deflection Curve (GCII-1)
Load
(kN)
Load
(kN)

79. 10
900
800
700
600
500
400
300
200
100
0
0 2 4 6 8 10
Deflection (mm)
Figure 4.30 Load versus Mid-height Deflection Curve (GCII-2)
700
600
500
400
300
200
100
0
0 2 4 6 8 10 12
Deflection (mm)
Figure 4.31 Load versus Mid-height Deflection Curve (GCII-3)
Load
(kN)
Load
(kN)

80. 10
1600
1400
1200
1000
800
600
400
200
0 0 2 4 6 8
Deflection (mm)
Figure 4.32 Load versus Mid-height Deflection Curve (GCIII-1)
1200
1000
800
600
400
200
0 0 2 4 6 8 10
Deflection (mm)
Figure 4.33 Load versus Mid-height Deflection Curve (GCIII-2)
Load
(kN)
Load
(kN)

81. 10
900
800
700
600
500
400
300
200
100
0
0 5 10 15
Deflection (mm)
Figure 4.34 Load versus Mid-height Deflection Curve (GCIII-3)
1800
1600
1400
1200
1000
800
600
400
200
0
0 2 4 6 8
Deflection (mm)
Figure 4.35 Load versus Mid-height Deflection Curve (GCIV-1)
Load
(kN)
Load
(kN)

82. 10
1200
1000
800
600
400
200
0
0 2 4 6 8 10 12
Deflection (mm)
Figure 4.36 Load versus Mid-height Deflection Curve (GCIV-2)
900
800
700
600
500
400
300
200
100
0
0 5 10 15
Deflection (mm)
Figure 4.37 Load versus Mid-height Deflection Curve (GCIV-3)
Load
(kN)
Load
(kN)

83. 10
4.3.4 Load Capacity
The results of the tests are summarised in Table 4.5, which may be seen below. Columns'
load capacities may be affected by a variety of parameters, including load eccentricity,
concrete compressive strength, and the ratio of longitudinal reinforcement. An increase in
the load capacity of the columns was seen, as was to be anticipated, in combination with
a decrease in the load eccentricity that was observed. There was an increase in the load
capacity if there was also an increase in either the compressive strength of the concrete or
the ratio of the longitudinal reinforcement.
Table 4.5 Summary of Column Test Results
Column
Concrete
Compres
Load Longitudinal
Reinforcement
At Failure
No. -sive
Strength
Eccentricity
(mm) Bars
Ratio Failure
Load
Mid-height
deflection at
4.3.5 Effect of Load Eccentricity
A plot of the failure load vs the load eccentricity of the test columns may be seen in Figure 4.38. As was to
be anticipated, the failure load fell in proportion to the increasing load eccentricity ratio.
(MPa) (%) (kN) failure load
GCI-1 42 15 4Y12 1.47 940 5.44
GCI-2 42 35 4Y12 1.47 674 8.02
GCI-3 42 50 4Y12 1.47 555 10.31
GCII-1 43 15 8Y12 2.95 1237 6.24
GCII-2 43 35 8Y12 2.95 852 9.08
GCII-3 43 50 8Y12 2.95 666 9.40
GCIII-1 66 15 4Y12 1.47 1455 4.94
GCIII-2 66 35 4Y12 1.47 1030 7.59
GCIII-3 66 50 4Y12 1.47 827 10.70
GCIV-1 59 15 8Y12 2.95 1559 5.59
GCIV-2 59 35 8Y12 2.95 1057 7.97
GCIV-3 59 50 8Y12 2.95 810 9.18

84. 10
2000
1800
1600
1400
1200
1000
800
600
400
200
0
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35
Load Eccentricity Ratio, e/D
Figure 4.38 Effect of Load Eccentricity
4.3.6 Effect of Concrete Compressive Strength
The impact that the compressive strength of the concrete has on the tensile strength of the
column is seen in Figures 4.39 and 4.40. These numbers show that there was a direct correlation
between an increase in the compressive strength of the concrete and a commensurate increase in
the load capacity of the test columns.
GCIV
GCIII
GCII
GCI
Failure
Load
(kN)

85. 10
1800
1600
1400
1200
1000
800
600
400
200
0
0 30 60 90
Concrete Compressive Strength (MPa)
Figure 4.39 Effect of Concrete Compressive Strength on Load Capacity (GCI
and GCI III Series)
1800
1600
1400
1200
1000
800
600
400
200
0
0 30 60 90
Concrete Compressive Strength (MPa)
Figure 4.40 Effect of Concrete Compressive Strength on Load Capacity (GCII
and GCI IV Series)
4.3.7 Effect of Longitudinal Reinforcement
The effect that the longitudinal reinforcement ratio has on the column failure load is seen in figure
4.41 below. As was to be expected, the failure load of the columns increased as a result of an
increase in the longitudinal reinforcement ratio, which led to an increase in the failure load.
 = 1.47%; e = 15mm
 = 1.47%; e = 35mm
 = 1.47%; e = 50mm
 = 2.95%; e = 15mm
 = 2.95%; e = 35mm
 = 2.95%; e = 50mm
Failure
Load
(kN)
Failure
Load
(kN)

86. 10
1600
1400
1200
1000
800
600
400
200
0
0 1 2 3 4
Longitudinal Reinforcement Ratio (%)
Figure 4.41 Effect of Longitudinal Reinforcement on Load Capacity
e = 15mm
e = 35mm
e = 50mm
Series GCI
Series GCII
Failure
Load
(kN)

87. 10
CHAPTER 5
CORRELATION OF TEST AND CALCULATED RESULTS
5.1 Introduction
In Section 5.2, the values that were calculated for the cracking moment and the ultimate
moment of reinforced geopolymer concrete beams are compared with the values that
were acquired through testing. These values were used to determine whether or not the
estimates were accurate. This data was used in order to establish the degree of accuracy
that could be attributed to the estimations. The estimated values were achieved by
adhering to the procedures described in the draught version of the Australian Standard
for Portland Cement Concrete, which is more often referred to as AS 3600. This
particular standard is referred to as AS 3600. (2005). In addition to anything similar to
this, the beam deflections that have been seen are contrasted with the beam deflections
that have been estimated by making use of the serviceability design requirements that
have been defined in Draught AS 3600. (2005).
In Section 5.3, comparisons are performed between the failure loads of reinforced
geopolymer test columns and the values that were estimated by making use of the thin
column design criteria that were supplied in AS 3600 and the American Concrete
Institute Construction Regulations ACI 318. The American Concrete Institute Building
Code serves as the basis for the comparisons that follow (2002). In addition, the results
of a simpler approach to stability analysis devised by Rangan are contrasted with the
test values in order to determine whether or not there is a correlation between the two
(1990).
In each and every computation that takes into account the strength, the reduction factor
for the strength is simply assumed to be one. This is the case regardless of whether or
not the strength is really taken into account.
5.2 Reinforced Geopolymer Concrete Beams
5.2.1 Cracking Moment

88. 10
Throughout the whole of the calculation, it was assumed that the flexural tensile
strength of geopolymer concrete was equivalent to 0.6 fc'. With the help of this
presumption, we were able to calculate the theoretical cracking moment mcr (Clause
6.1.1.2, AS 3600). Calculating the drying shrinkage strain, which was necessary for the
calculations, required the use of the test data that Wallah and Rangan (2006) provided
for heat-cured low-calcium fly ash-based geopolymer concrete. These findings were
utilised to determine the drying shrinkage strain. It was essential to carry out these steps
in order to guarantee that the calculations would be accurate. The information pertaining
to both of these groups may be found for your consideration in Table C.1.
The results of the tests are compared with the cracking moments that were computed,
and the findings may be seen in Table 5.1. The ratio of the cracking moment measured
during the test to the value that was expected was 1.35, with a standard deviation of
0.09.