ARBAMINCH UNIVERSITY

INSTITUTE OF TECHNOLOGY

FACULTY OF CIVIL ENGINEERING

BSC THESIS ON

EFFECTS OF PARTIAL REPLACEMENT OF WOODEN ASH WITH

CEMENT ON CONCRETE PROPERTIES

ADVISOR: SHAMBLE KIFLE (MSC)

GEZAHIGN ZERIHUN (MSc)

JUNE, 2019

Arba Minch, Ethiopia

BSc Thesis Submitted To the Faculty Of Civil Engineering, Arbaminch
Institute Of Technology, in Partial Fulfillment of the Requirement for
Degree of Bachelor of Science in Civil Engineering.

JUNE, 2019
 DECLARATION

We declare that this thesis is our own and original work of us and all sources of material
used for this thesis have been properly acknowledged, following scientific guidelines of
institute of technology.

NO. Student’s Name: ID number Signature

1 Getahun Tisasu RAMIT/661/07

2 Yesera Belachew RAMIT/1510/07
3 Gulte Nageso RAMIT/688/07
4 Sitota Setegn RAMIT/1317/07
5 Samson G/meskel RAMIT/1236/07
6 Tesfaye Kefani RAMIT/1402/07
7 Cherenet Mekoya RAMIT/401/07
8 Yewdiyanesh Abebe RAMIT/1520/07
 ADVISOR THESIS APPROVAL SHEET

ARBA MINCH INSTITUTE OF TECHNOLOGY

This is to certify that, the thesis entitled “The Partial replacement of Eucalyptus wooden
ash in concrete, which could be submitted for partial fulfillment of the requirements for
the bachelor of Science in degree, the under Graduate Program of the Department of
Civil Engineering, Institute of Technology, School of under Graduate Studies Arba
Minch University Under my supervision, and has been carried out by:

1. GETAHUN TISASU

2. YESERA BELACHEW

3. GULTE NAGESO

4. SITOTA SETEGN

5. SAMSON G/MESKEL

6. TESFAYE KEFANI

7. CHERENET MEKOYA

8. YEWDIYANESH ABEBE

Therefore I recommend that the students have fulfilled the requirements and hence
hereby can submit the thesis to the department for defense.

Name of principal advisor: Shambel kifle (MSc)

Signature___________ Date______________

Gezahegn zerihun (MSc)

Signature___________Date_____________
ACKNOWLEDGEMENT

With the deepest gratitude, we wish to thank GOD for his endless support and we would
like to acknowledge to our advisors instructor Shamble k. and Gezahegn Z. for their
willing, motivation, and immense knowledge to the research time and to the report.

Beside our advisors, we would like to thank Arba Minch University Institute of
Technology for their laboratory facilitation and Etete construction plc. Their support by
providing materials.

Our sincere thanks also go to our group for their team spirit and motivation to work hard
and to do better.

ii
ABSTRACT

Rapid development of construction industry increased demand of consumption of

cement. But productions of cement increase the greenhouse gases and carbon dioxide, in
addition to that the cost of construction also increase rapidly due to the increment of
cement price year to year.

The objective of the research is to examine the effect of partial replacement of eucalyptus
wood ash workability of fresh concrete, compressive strength and density of hardened
concrete.

The scope of the research covered the potential of using eucalyptus wood ash as a cement
replacement material. The methodology of the study was mainly laboratory testing of the
materials. Wood ash limited to the grain size of less than 75µm is added to cement by
weight percentage of 10%, 15%, 20% and 25% by the method of replacement by weight.
Concrete with no wood ash serves as control. The mix ratio used was 1:1.97:2.91 with
water to binder ratio maintained at 0.53. The Compressive strength was determined at
curing ages 7, 14 and 28 days.

The compressive strength of wood ash concrete decreases with increasing wood ash
content. There was a sharp decrease in compressive strength beyond 20% wood ash
substitution. It was concluded that a maximum of 20 %,( 30.87Mpa) wood ash
substitution is adequate for use in structural concrete.

The main recommendation therefore was to replace cement with 20% eucalyptus wood
ash as this particular proportion of replacement would enable cost savings, reduction of
environmental pollution and achievement of normal strength concrete as well.

Keywords: Wood ash, Compressive strength, Cement replacement materials,

Environmental Friendly,

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TABLE OF CONTENTS

ACKNOWLEDGEMENT .................................................................................................. ii

ABSTRACT ....................................................................................................................... iii

LIST OF ABBREVIATION .............................................................................................. vi

LIST OF FIGURE............................................................................................................. vii

LIST OF TABLES ........................................................................................................... viii

CHAPTER ONE ................................................................................................................. 1

INTRODUCTION .............................................................................................................. 1

1.1 Background ............................................................................................................... 1

1.2 Statement of the problem .......................................................................................... 2

1.3 Research Question .................................................................................................... 3

1.4. The Research Objective ........................................................................................... 3

1.4.1 General Objective .............................................................................................. 3

1.4.2 Specific Objectives ............................................................................................ 3

1.5. Significance of the Study ......................................................................................... 3

1.6 Scope of the Research ............................................................................................... 4

1.7 Operational Definitions ............................................................................................. 4

CHAPTER TWO ................................................................................................................ 6

LITERATURE REVIEW ................................................................................................... 6

2.1 Concrete and concrete making materials .................................................................. 6

2.2. Partial Replacement Materials for cement in concrete production ........................ 15

CHAPTER THREE .......................................................................................................... 23

RESEARCH METHODOLOGY...................................................................................... 23
iv
 3.1 Introduction ............................................................................................................. 23

3.2 Materials and test methods...................................................................................... 24

3.3 Concrete mix design ............................................................................................... 41

3.4 Concrete test............................................................................................................ 44

CHAPTER FOUR ............................................................................................................. 50

RESULTS AND DISCUSSION ....................................................................................... 50

4.1 Fresh concrete test result and discussion ................................................................ 50

4.1.1 Slump test......................................................................................................... 50

4.1.2 Unit weight or Density of fresh concrete ......................................................... 51

4.2 Hardened concrete test result and discussion.......................................................... 52

4.2.1 Unit weight of hardened concrete .................................................................... 52

4.2.2 Compressive Strength test result ...................................................................... 54

4.2.3 Rebound Hammer test result ............................................................................ 58

4.2.4 Ultrasonic pulse velocity test result ................................................................. 59

CHAPTER FIVE .............................................................................................................. 60

CONCLUSION AND RECOMMENDATIONS ............................................................. 60

5.1 Conclusion .............................................................................................................. 60

5.2 Recommendations ................................................................................................... 61

REFERENCES ................................................................................................................. 62

APPENDIX I .................................................................................................................... 63

APPENDIX II ................................................................................................................... 67

v
LIST OF ABBREVIATION
Mpa: - Mega Pascale

WA: - Wooden ash

ASTM: - America society for testing and materials

C – 25: - Concrete grade for25MPa compressive strength

SSD: - Surface saturated Dry

OD: - oven dry

IS: - Indian standard

ACI: - American concrete institutes

AASTHO: - American Association society of Transport and Highway office

UPV:-Ultrasonic pulse velocity

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LIST OF FIGURE

Figure 1.Flow chart ........................................................................................................... 23

Figure 2.Concrete ingredients ........................................................................................... 24

Figure 3. Gradation curve for coarse aggregate ................................................................ 28

.Figure 4.Gradation curve for fine aggregate .................................................................... 33

Figure 5. Silt content test specimen .................................................................................. 38

Figure 6.Bulking sand test specimen ................................................................................ 40

Figure 7.Slump test ........................................................................................................... 45

Figure 8.Compressive strength test ................................................................................... 46

Figure 9.Rebound hammer test ......................................................................................... 48

Figure 10.Ultrasonic pulse velocity test............................................................................ 49

Figure 11. Slump height versus eucalyptus ash graph ...................................................... 50

Figure 12.Fresh concrete density diagram ........................................................................ 51

Figure 13. Harden concrete density diagram .................................................................... 52

Figure 14. Summary for density of concrete .................................................................... 53

Figure 15. Compressive strength of 7days ........................................................................ 55

Figure 16. Compressive strength of 14 days ..................................................................... 55

Figure 17. Compressive strength of 28 days ..................................................................... 56

Figure 18. Summary of Compressive strength ................................................................. 57

Figure 19.Rebound hammer test ....................................................................................... 58

Figure 20. Ultrasonic pulse velocity test result ................................................................. 59

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LIST OF TABLES

Table 1 Chemical composition of ordinary Portland cement ........................................... 11

Table 2 Chemical composition of wood ash and comparison with OPC ......................... 18

Table 3 Specific Gravity of Coarse Aggregate ................................................................. 26

Table 4 Grain Size Distribution of Coarse Aggregate ...................................................... 27

Table 5 Absorption Capacity of Coarse Aggregate ....................................................... 29

Table 6 Bulk Density of Coarse Aggregate ...................................................................... 30

Table 7 Gradation for fine aggregate ................................................................................ 32

Table 8 Bulk specific gravity on saturated surface dry..................................................... 34

Table 9 Apparent specific gravity ..................................................................................... 35

Table 10 Absorption capacity ........................................................................................... 35

Table 11 Bulk density of sand .......................................................................................... 36

Table 12 Water content of sand ........................................................................................ 37

Table 13 Silt content of sand ............................................................................................ 39

Table 14 Bulking of Sand Test ......................................................................................... 40

Table 15 Final mix design................................................................................................. 43

Table 16 proportion of cement to eucalyptus wood ash per m3 of concrete .................... 44

Table 17 Slump test result................................................................................................. 50

Table 18 Density of fresh concrete ................................................................................... 51

Table 19 Density of hardened concrete ............................................................................ 52

Table 20 Summary of concrete density ............................................................................ 53

Table 21 Compressive Strength test result........................................................................ 54

viii
Table 22 Summary for compressive strength ................................................................... 57

Table 23 Summary for rebound hammer test result.......................................................... 58

Table 24 Ultrasonic pulse velocity test result ................................................................... 59

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BSC THESIS REPORT 2019

CHAPTER ONE

INTRODUCTION

1.1 Background

Concrete is made of cement, water, sand, and gravel mixed in definite proportions,
whereas mortar consists of cement, water, and aggregate. These are both used to bind
rocks, stones, bricks and other building units, fill or seal any gaps, and to make
decorative patterns.

The rapid development of construction industry increased the demand of consumption

cement. Cement, one of the most important building materials, is a binding agent that sets
and hardens to adhere to building units such as stones, bricks, tiles etc. It is an integral
part of the urban infrastructure. Cement generally refers to a very fine powdery substance
chiefly made up of limestone (calcium), sand or clay (silicon), bauxite (aluminum) and
iron ore, and may include shells, chalk, marl, shale, clay, blast furnace slag and slate. It is
used to make concrete as well as mortar, and to secure the infrastructure by binding the
building blocks.

The production of cement involves the depletion of natural resources and greenhouse gas
emissions. Thus, there is need to search for alternative materials to cement in the
construction. Continuous generation of wastes arising from industrial by-products and
agricultural residue, create acute environmental problems both in terms of their treatment
and disposal. The construction industry has been identified as the one that absorbs the
majority of such materials as filler in concrete.

Some industrial wastes have been studied for use as supplementary cementing materials
such as Fly ash, Silica fume, Pulverized fuel ash, volcanic ash, Rice husk ash and Corn
cob ash (CCA).

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Wood waste ash is generated as a by-product of combustion in wood-fired power plants,

paper mills, and other wood burning facilities. The wood ash incorporated as partial
replacement of cement helps avoiding insignificant and bulk consumption of pure
cement. Besides this, the production of cement material all alone results in increased
emission of certain greenhouse gases and much more pollutants. Hence replacing with
wood ash leads to less production of cement, thus proving environmentally safe. Apart
from this, this replacing technique also reduces the cost. The characteristic of ashes will
be different for different types of agricultural wastes, timber, etc. These characteristics
depend upon the (1) biomass characteristics (2) Incinerating technology and (3) location
from where wood ash is obtained.

The ultimate aim of this study is to analyze the effect of eucalyptus wooden ash on
different major properties of concrete.

1.2 Statement of the problem

Wood ash contains amorphous silica making it fit as cement replacing material
due to its high pozzolanic activity. In many countries, the wood industries generate a
large amount of waste products in the worldwide.

The low costs, the proximity of the sources and the potential pollution from wood wastes
have led to studies into the possible use of the wood ash as fibers in concrete.
Incorporating the usage of wood ash as replacement for cement in blended cement is
beneficial for the environmental point of view as well as producing low cost
construction entity thus leading to a sustainable relationship. As the disposal cost of the
ashes are rising and volume of ash is increasing, a sustainable ash management
which integrate the ash within the natural cycles needs to be employed.

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1.3 Research Question

 What is the effect of partial replacement of cement by wood ash in fresh concrete
property?
 What is the effect of partial replacement of cement by wood ash in hardened
concrete property?
 What is the optimum percentage replacement of wooden ash in the concrete?

1.4. The Research Objective

1.4.1 General Objective

The general objective of the research is to evaluate the importance of eucalyptus wooden
ash as a partial replacement of cement in concrete.

1.4.2 Specific Objectives

The specific objectives of the research include: -

 To examine the effect of partial replacement of wood ash on fresh concrete

property.
 To investigate the effect of partial replacement of wood ash on hardened concrete
property.
 To examine the optimum percentage replacement of wooden ash in concrete.

1.5. Significance of the Study

In developing countries like Ethiopia most of the people uses wood in its day to day
activity for preparing food and other purposes. Using wood causes high amount of wood
waste ash, this needs wide land fill area and it becomes the factor for environmental
pollution. On the other hand, due to the booming of the construction industry, the demand
and consumption cement is largely increasing from time to time which causes large

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natural resource depletion and increase construction cost. Thus, the replacement cement
by waste wood ash has got importance in reducing the cost to cement and ensuring cost
efficient construction, and also contributes to clean and green environment by reducing
the wastes from wooden ash.

1.6 Scope of the Research

This research is focused specially on strength of concrete which cement is partially

replaced by pure eucalyptus ash. The Study was to evaluate the property of concrete
under different substitution of wood ash with different proportion to achieve a better
study of the wood ash concrete properties that are essential for cost-effective structures
and environmental effect reduction.

The research is focused on evaluating the eucalyptus wooden ash as partial replacement
of cement for C-25 concrete grade. Fresh (slump, ) and hardened (compression strength,
ultrasonic pulse velocity, rebound hammer) concrete laboratory tests were conducted to
reach on conclusion. Other essential properties like ,flexural strength, Durability, and
permeability tests were not conducted due to the reason of unavailability and/or
malfunctioning of laboratory equipment’s, and also scarcity of raw materials like cement.
The research result will be affected by calibration of laboratory equipment’s, degree of
compaction and skill of manpower.

1.7 Operational Definitions

Wood ash: - is the residue powder left after the combustion of wood, such as burning
wood in a home fireplace or an industrial power plant. It is used traditionally
by gardeners as a good source of potash.

Compressive strength: - Test is performed to determine the Compressive Strength of

concrete. For cube compression testing of concrete, 150mm cubes were used at different
days like 7 days, 14days, and 28 days.

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Cement replacement materials: - are materials used to contribute to the properties of

hardened concrete through hydraulic or pozzolanic activity or both.

Environmentally friendly: -are sustainability and marketing terms referring to goods

and services, laws, guidelines and policies that claim reduced, minimal, or no harm upon
ecosystems or the environment.

Strength: - is a subject who deals with the behavior of solid objects subject to stresses
and strains.

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CHAPTER TWO

LITERATURE REVIEW

The literature of the study involves recent findings pertaining to the application of wood
ash as a partial replacement for cement. It attempts to review material applied in the
construction industry about the suitability of wood ash in cement-based material
comparing the compression strength attained in the different percentages of the mix
design of concrete. (Wood ash, cement, concrete, mix design and construction industry).

2.1 Concrete and concrete making materials

Concrete is composed mainly of three materials, namely, cement, water and aggregate
(“inert” mineral fillers), and an additional material, known as an admixture, is sometimes
added to modify certain of its properties. When these materials are mixed and placed in
forms and allowed to curing, the chemical reaction between the water and cement forms a
hardened binding medium of cement paste, which surrounds and holds together the
aggregates by adhering them to a varying degree. Hence the properties of concrete may
be governed by careful selection (design) and control of the constituent materials. The
requirements for a fresh and a hardened concrete may vary in wide range, dependent on
the type of structure to be cast and the available equipment.

2.1.1 Cement

Cement is a binder substance used for construction that set, harden and adheres to other
material to bind them together. Cement is seldom used on its Owen, but rather to bind
sand and gravel (aggregate) together. Cement mixed with fine aggregate produces mortar
for masonry, or with sand and gravel, produces concrete. A number of different types of
cement are manufactured, by varying the ratio of the raw material and/or by adding some
additional materials.

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Some of the most common cement classifications are:

 ordinary Portland cement (type-I)

 Rapid hardening cement
 Low heat cement
 Quick setting cement
 High alumina cement
 Blast furnace slag cement
 Pozzolana cement
 Super sulfate cement
 Air entraining cement
Ordinary Portland cement: Portland cement is a product obtained by the calcination at
a very high temperature, an intimate mixture of correctly proportioned calcareous and
argillaceous materials. Clinker is then finally pulverized by grinding into a very fine
powder and is finally mixed with calcium sulfate or gypsum to obtain cement.

The commonly raw material included in cement is as follow.

i. Calcareous materials and

ii. Argillaceous materials.

The Calcareous materials include compounds of calcium and magnesium, such as

Limestone. And argillaceous ones include mainly silica, alumina, and oxide of iron such
as clay and shale. Cement is manufactured in several varieties, but the most common one
used is the normal setting or ordinary cement, usually called Portland cement.

These are manufactured with two or more raw materials. They have to be correctly
proportioned and thoroughly mixed. Lime, silica, and alumina are the important
ingredients.

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Rapid Hardening Cement: It is also known as High-Early-Strength cement. It is

manufactured with such adjustments in the proportion of raw materials. So that the
cement produced attains maximum strength with-in 24-72 hours.

Two essential properties of Rapid Hardening Cement are following.

 It contains relatively more tri-calcium silicate. This is done by adding a greater

proportion of limestone in the raw materials compared to that required for
ordinary cement.
 It is more fine-grained (Air permeability 3250 cm2/gm.) than the ordinary
cement.

This factor helps in quicker and complete hydration of cement particles during setting
and helps in gaining early strength. However, the setting time and ultimate strength of
Rapid Hardening Cement are same as of Ordinary Cement.

It is special purpose cement, used in those types of projects, where quick hardening is
required..

Low Heat Cement: It is that type in which a very low amount of heat or hydration is
liberated during setting and hardening. Mostly it is used in massive concrete structures
like Dams etc.

 The proportion of di-calcium silicate (C2S) is almost double than ordinary

cement.
 The proportion of tetra calcium alumino-ferrite (C4AlFe) is also increased to one
and one-half time.
 The proportion of tricalcium silicate (C3S) and tri-calcium aluminate (C3Al) is
reduced by about 50 percent. This is because these compounds are known to
liberate a very high amount of heat during hydration.

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It is mostly used in mega projects construction like DAMS. If we use ordinary Portland
cement instead of low heat cement in such structures, Cracks will develop in such
structures due to the great amount of heat liberated during setting and hardening. And a
DAM with cracks is a useless structure. But when low heat cement is used, this danger
(development of cracks) can be eliminated.

Quick Setting Cement: These Types of Cement are quite different than rapid hardening
cement. Its quality is that it set into a stone-like mass within a period of fewer than 30
minutes. This property, of setting as quickly as possible is achieved by following controls
in the manufacturing process:

 The quantity of retarding agents like gypsum is reduced to a bare minimum.

 The quantity of alumina-rich compound is reduced.
 The clinker is ground to extreme fineness.

High Alumina Cement: These Types of Cement contains alumina in considerably larger
proportions (average 40 percent) than normal cement. High Alumina cement is
manufactured by calcining a well-proportioned mixture of Limestone and Bauxite
(Al2O3, n H2O). No other raw material is added, not even gypsum is mixed with the
clinker during grinding. The total Alumina content is generally above 32 percent.

Properties:

The most important properties of high alumina cement are summarized below:

 It is resistant to the corrosive action of acids and salts of seawater.

 The ratio of alumina to lime is kept between 0.85 and 1.30.
 It gains compressive strength of 400 kg/sq.cm within 24 hours and 500 kg/sq.cm
after 72 hours.
 It evolves great heat during setting. Due to this, it is not suitable for use in mega
projects like Dams.
 It is commonly used in construction work near and along sea-shore.

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Blast Furnace Slag Cement: It is a modified type of Portland cement which contains 25-
65 percent (by weight) of blast furnace slag. It is manufactured by grinding clinker and
specific amounts of blast furnace slag together. A small percent of gypsum is also added
for controlling its setting time. The slag, as we know, is a waste product from the blast
furnace which is used in the manufacture of iron (Ferrous Metal).

Properties: The slag cement offers a number of advantages, which are the following.

 They possess better workability, cohesiveness, and plasticity. These qualities are
explained to be due to lesser specific gravity and greater specific surface area of
slag cement.
 They have better resistance to sulfates of alkali metals, alumina, and iron.
 It produces low heat. This property makes it useful for use in mega projects like
Dams.
 It is economical as compared to ordinary cement.

It is better suited for use in marine structures as in docks, harbors, and jetties. It is also
used in road construction in marshy and alkaline soils.

Pozzolana Cement: In this cement type, clinker and pozzolanic material such as
(volcanic ash, fly ash, etc.) are mixed in a definite proportion with Portland cement. The
pozzolanic materials do not have any cementing qualities when used alone, but when
mixed with Portland cement, they react with cement components and form compounds
with cementing properties. The pozzolana cement has many properties similar to ordinary
Portland cement. But it also offers some additional properties, which are given below.

 It produces less heat. Due to this property, it can be used in mega projects.
 It offers greater resistance to sulfates and corrosive actions of sea water.

Super Sulfate Cement: These types of cement are manufactured by adding additional
quantities of calcium sulfate and blast furnace slag in the Portland cement. It is especially

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useful for mass concrete work especially in sulfate-rich environment and marine
conditions. Besides, it is comparatively economical than other types of cement.

Air Entraining Cement: This cement type is manufactured by adding some indigenous
air entraining agents such as glues, resins, sulfates, etc., during the grinding stage of
clinker. They are used to improve the workability of concrete with smaller water-cement
ratio and they also improve the frost resistance of concrete.

Table 1 Chemical composition of ordinary Portland cement

Compounds Average Average Averages

chemical chemical chemical
composition composition PPC composition PLC
OPC
SiO2 20.5 30 21.1
Al2O3 5.4 8.5 4.9
Fe2O3 4.6 5.45 2.7
CaO 62.5 42 66.3
MgO 0.6 1.5 1
SO3 2.6 2.6 2.6
Loss on ignition 2 3.25 5.5

2.1.2 Water

Generally, water is a key ingredient in the manufacture of concrete work. Water fit for
drinking is generally suitable for making concrete. It is also material on its own right.
Understanding its properties is helpful in gaining and understanding of its effects on
concrete and other building materials. Although water is an important ingredient of
concrete little needs to be written about water quality, since it has little to do with the
quality of the concrete. However, mixing water can cause problems by introducing
impurities that have detrimental effects on concrete quality.

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2.1.3 Aggregate

Aggregate is a granular material, such as sand, gravel, crushed stone or iron-blast furnace
slag. All materials that pass-through sieve 4.75mm is conventionally referred to as a fine
aggregate or sand, while all materials that retained sieve 4.75mm is referred as coarse
aggregates, gravel, or stone. Also, it is filler materials which make up a large portion
(roughly 65-80%) of the concrete volume. Considerable care should be taken to provide
the best aggregates available. They should be hard, clean and free of any harmful matter
to an extent which would adversely affect the hardening of a binder, or the strength or
durability of the finished material in which they are put.

The quality requirements of Aggregates

It should consist of naturally occurring (crushed or uncrushed) stones, gravel and sand or
combination thereof. They should be hard, strong, dense, durable, clear and free from
veins and adherent coating, and free from injurious amounts of disintegrated pieces,
alkali, vegetable matter and other deleterious substances. Also, possible, flaky,
coriaceous and elongated pieces are avoided.

Visual inspection of gravel and natural sand is necessary for presence of clay lumps, clay
coating, silt, grading and shape, while for crushed aggregates and sand inspection is
necessary for stone dust, flaky shape and grading. If clay dust silt or mud is present and
not removed/reduce through washing, it may produce lower strength concrete.

Classifications are on the basis of source and specific gravity. Aggregates are classified
as natural or artificial aggregates according to their source:

i. Natural aggregates: Natural aggregates are those taken from native deposits with
no and, gravel, crushed stone, and pumice is examples of Natural aggregates.
ii. Artificial aggregates: Artificial aggregates are those materials or particles which
are obtained either as a by-product of an unrelated industrial process or by a
special manufacturing process like heat treatment. Blast-furnace slag is typical

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example of a by-product aggregate; expanded perlite, expanded vermiculite,

burned clay and fly ash aggregate are example of aggregates Produced by heat
treatment.
With regard to their specific gravity or unit weight, concrete aggregates are classified as:

i. Normal weight aggregates: Normal weight aggregates have specific Gravities of

between 2.4 and 2.8.
ii. Lightweight aggregates: Aggregates with a specific gravity of less than 2.4 are
called lightweight aggregates. Lightweight aggregates have many sources:- Natural
materials such as shale’s, clays, pumice, diatomite, volcanic cinders, and slates or
artificial materials (by products) such as iron blast furnace slag, clay, sintered fly
ash, and shale.
iii. Heavyweight aggregates
2.1.4 Admixtures

A material other than water, aggregates, or cement that is used as an ingredient of

concrete to control setting and early hardening, workability, or to provide additional
cementing properties. An admixture can be defined as a chemical product which is added
to the concrete mix in quantities no larger than 5% by mass of cement during mixing or
during an additional mixing operation prior to the placing of concrete, for the purpose of
achieving specific modification to normal properties of concrete at the mixing stage to
modify some of the properties of the mix.

Types of Admixtures

There are two types: - 1. Chemical admixtures: - Accelerators, Retarders, Water-reducing

agents, Super plasticizers, Air entraining agents etc. 2. Mineral admixtures - Fly-ash,
Blast-furnace slag, Silica fume and Rice husk Ash etc.

Water-reducing admixture / Plasticizers: - These admixtures are used for following

purposes: To achieve a higher strength by decreasing the water cement ratio at the same
workability as an admixture free mix, To achieve the same workability by decreasing the
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cement content so as to reduce the heat of hydration in mass concrete, To increase the
workability so as to ease placing in accessible locations.

Accelerators: An admixture which, when added to concrete, mortar, or grout, increases

the rate of hydration of hydraulic cement, shortens the time of set in concrete, or
increases the rate of hardening or strength development. Accelerating admixtures have a
relatively limited effect and are usually only cost effective in specific cases where very
early strength is needed for, say, access reasons. They find most use at low temperatures
where concrete strength gain may be very slow so that the relative benefit of the
admixture becomes more apparent.

Set Retarders Admixture: The function of retarder is to delay or extend the setting time
of cement paste in concrete. This is useful when used with plasticizers to give workability
retention. Used on their own, retarders allow later vibration of the concrete to prevent the
formation of cold joints between layers of concrete placed with a significant delay
between them. The mechanism of set retards is based on absorption. The commonly
known retards are Calcium Ligno-sulphonate sand Carbohydrates derivatives used in
fraction of percent by weight of cement.

Air Entrained Admixtures: An addition for hydraulic cement or an admixture for

concrete or mortar which causes air, usually in small quantity, to be incorporated in the
form of minute bubbles in the concrete or mortar during mixing, usually to increase its
workability and frost resistance. Air entrainment is used to produce a number of effects in
both the plastic and the hardened concrete. These include: - Resistance to freeze–thaw
action in the hardened concrete, Compaction of low workability mixes including semi-
dry concrete and increased cohesion, reducing the tendency to bleed and segregation in
the plastic concrete.

Cementitious: These have cementing properties themselves. For example Ground

granulated blast-furnace slag(GGBFS) is the granular material formed when molten iron
blast furnace slag (a by-product of iron and steel making) is rapidly chilled (quenched) by

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immersion in water GGBFS is used to make durable concrete structures in combination

with ordinary Portland cement and/or other Pozzolanic materials. Use of GGBFS
significantly reduces the risk of damages caused by alkali-silica reaction (ASR), provides
higher resistance to chloride ingress, reducing the risk of reinforcement corrosion, and
provides higher resistance to attacks by sulfate and other chemicals.

Pozzolanic: A pozzolana is a material which, when combined with calcium hydroxide

(lime), exhibits cementitious properties. Pozzolans are commonly used as an addition (the
technical term is "cement extender") to Portland cement concrete mixtures to increase the
long-term strength and other material properties of Portland cement concrete and in some
cases reduce the material cost of concrete.

Fly Ash: It is finely divided residue resulting from the combustion of ground or
powdered coal. Fly ash is generally captured from the chimneys of coal-fired power
plants; it has Pozzolanic properties, and is sometimes blended with cement for this
reason.

2.2. Partial Replacement Materials for cement in concrete production

2.2.1. The importance (necessity) of replacement of cement

Use of replacement materials is an efficient way of reducing the burden on the

environment because of construction activities. They would reduce the embodied
energy and improve the durability of construction materials (W.W.J. Chan et al), thus
contributing towards the sustainability of our environment. Not only to the environmental
problems but also the problem of the economic design of building (torkman, J. and
Momtazi, A.S. (2014).

2.2.2. The potential replacement materials for cement in concrete

Cement replacement materials or mineral admixtures are materials used to contribute to

the properties of hardened concrete. Some of these are: -coal fly ash, ground granulated

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blast furnace slag, silica fume, ground glass natural Pozzolans or calcined clay (e.g.,
metakaolin), zeolite, coal bottom ash, wood fiber waste, rice husk ash and limestone
powder waste.

Fly ash (pulverized-fuel ash: PFA): It is the ash precipitated electrostatically or

mechanically from exhaust gases of coal-fired power stations. It has spherical particles
and high fineness which give it advantages from water requirements. Ground Granulated
blast-furnace slag (GGBS): Waste product in production of pig iron. It is a mixture of
lime, silica and alumina. It generally reduces water demand and improves workability.
Blending of PC and GGBS produces Portland blast furnace cement. Ramezanianpour, A.
A. (2014).

Silica fume: Also known as micro silica or condensed silica fume. It is an ultrafine
powder collected as a by- product of the silicon and ferrosilicon alloy. It is highly
reactive, the smallness of the particles speed up the reaction with calcium hydroxide.
Very small particles of silica fume can enter the space between the particles of cement
and thus improves packing. Silica fume is usually incorporated in the mix at the batcher.
Blended cement containing silica fume (6.5 to 8% by mass). Ramezanianpour, A. A.
(2014).

Natural Pozzolans: These are materials with presence of moisture, chemically reacts
with the calcium hydroxide released by the hydration of Portland cement to form calcium
silica hydrate. Ramezanianpour, A. A. (2014).

These materials are used as: Supplementary cementing materials added to concrete as
part of the total cementing system. Used as a partial replacement of Portland cement or
blended cement. These materials are used to improve a particular concrete property.
Optimum amount: to be established by testing / trial mix.

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Wooden ash

Cement replacement materials: - the research enables to construct light weight structures
and less costly concrete structures by partially replacing Portland cement by wooden ash.

Wood Ash (WA) prepared from the uncontrolled burning of the wood is evaluated for its
suitability as partial cement replacement in conventional concrete. Wooden ash is
residual powder left after the combustion of wood, such as burning wood in home fire
place or an industrial power plant. It is used traditionally by gardeners as a good source
of potash.

Wooden Ash as a partial replacement of cement

Wooden Ash is composed of many major and minor elements that trees need for growth.
Since most of these elements are extracted from the soil and atmosphere during the tree's
growth, they are common in our environment and are also essential in production of
crops and forages. Calcium is the most abundant element in wood ash and gives ash
properties similar to agricultural lime. Ash is also a good source of potassium,
phosphorus, and magnesium. In terms of commercial fertilizer, average wood ash would
be about 0-1-3 (N-P-K) mean nitrogen, phosphorus and potassium respectively. In
addition to these macro-nutrients, wood ash is a good source of many micronutrients
needed in trace amounts for adequate plant growth. Wood ash contains few elements that
pose environmental problems. Hardwoods usually produce more ash than softwoods, and
the bark and leaves generally produce more ash than the inner woody parts of the tree.
When ash is produced in industrial combustion systems, the temperature of combustion,
cleanliness of the fuel wood, the collection location, and the process can also have
profound effects on the nature of the ash material.

Therefore, wood ash composition can vary depending on geographical location and
industrial processes. This makes testing the ash extremely important.

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Table 2 Chemical composition of wood ash and comparison with OPC

Tarun, Rudolph and Rafat reported the following compound composition limits.

Compound composition Percentage composition of Percentage composition of

wood ash OPC cement
Silica (SiO2) 4 to 60% 17 to 25%
Alumina (Al2O3) 5 to 20% 3 to 8%
Iron oxide (Fe2O3) 10 to 90% 0.5 to 6%
Lime (CaO) 2 to 37% 60 to 67%
Magnesia (MgO) 0.7 to 5% 0.1 to 4%
Potash (K2O) 0.4 to 14% 0.5 to 1.3%

Naik et al. (2002): studied the drying shrinkage properties of concrete mixtures made by
the incorporation of wood waste ash as a partial cement replacement material. For mixes
produced during the study, wood ash was used at cement substitution level of 0, 5, 8 and
12%. Length changes of concrete specimens produced were monitored up to 232 days. It
was reported that the shrinkage value of control concrete specimens was 0.0092% (7
days) ,0.052% (232 days). Meanwhile shrinkage values of concrete mixtures with 5, 8
and 12% were recorded to 0.012%−0.027%, 0.014%/−0.013% and 0.0051%−0.044%.
From the results of drying shrinkage, it was observed that the inclusion of wood waste
ash significantly contributed to the reduction in magnitude of concrete upon drying. This
is a desirable attribute which may reduce formation of micro cracks within concrete mix
on drying.

Udeyo and Dashibil, (2002): They had common findings that show the use of wood
waste ash as a partial cement replacement material in concrete at all level of cement
replacement ranged between 5% and 30% it reduces the compressive strength of the
concrete mix produced relative to neat OPC concrete for all curing times.

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Udeyo and Dashibil (2002): reported a reduction in both the compression and split
tensile strength of concrete produced by partial replacement of cement with wood waste
ash. Split tensile strength of concrete mixes at 7 and 28 days was observed to decline
with increasing level of cement replacement with wood waste ash. The effects of
reduction in split tensile strength of concrete by the use of wood waste ash as partial
cement replacement material was less pronounced in comparison with reduction in
compressive strength. It was observed that the marginal difference in split tensile strength
of SDA/OPC concrete mixes with reference to neat OPC concrete were more significant
at 7 days. However, at 28 days the SDA/OPC concrete mixes with a cement replacement
level up to 25% total binder weight exhibited a split tensile strength values of over 90%
of split tensile strength of neat OPC concrete.

Udoeyo and Dashibil (2002): investigated the resistance of concrete containing wood
waste ash against acid attack. Two batches of concrete specimens having the same mix
proportions (1 cement: 2 sand: 4 gravel and w/c ratio of 0.65) were produced. One of the
batches contained neat OPC as a binder while the other batch had 15% total binder
weight of wood waste ash used in partial replacement of cement and 85% total binder
weight of cement.

At the tenth week of immersion, there was observable mass decrease in both batches of
specimens and it could be noted that mass decrease of the concrete specimens with 15%
total binder weight of wood ash were less pronounced in comparison to control concrete
specimens with neat OPC as binder.

Naik et al. (2004) investigate that the property of wood waste ash particles collected
from different sources located in different areas. The specific gravity obtained 2.26 to 2.6
and fineness of (% retained on 45 µm sieve) -23% to90%.

As there are no standards available to test the characteristics of wood waste

ash, Naik et al. adopted ASTM C618,1994 standards usually referred for ash
particles obtained from volcanic eruptions and incineration of coal substances. From the

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obtained result a conclusion is drawn that source of WA also influences the

properties both at macro and micro level.

Elinwa and Ejeh (2004): studied the effects of the incorporation of wood waste ash as a
partial cement replacement material in mortar mixes on its water absorption property.
Two batches of mortar mixes with the same mix proportions (1 binder: 3 sand: 0.6 w/b
ratio) were cast whereby one batch contained 15% wood waste ash as a partial
replacement material while the other had no wood waste ash content. It was observed that
inclusion of wood waste ash as a cement replacement material at 15% total binder weight
contributed towards the reduction in water absorption of the mortar mix produced.
Average water absorptions of mortar mixes with 15% of wood waste ash and without
wood waste ash content were recorded to be 0.8% and 1.25% respectively whereby both
are still far below maximum of 10%.

Abdullia et al. (2006): Investigated the effect of wooden ash on concrete compressive
strength for 5%,10%,15%,20% and 25% replacement of cement with wooden ash. After
conducting the test, he concludes that the optimum percentage of wooden ash
replacement is 15%.but the sample was crushed for 7th, 14th and 21th days this may
cause variation in test results.

Abdullahi (2006) : studied the influence of wood ash (WA) on the slump of concrete. He
used wood ash as partial replacement of cement in varying percentages (0, 10, 20, 30, and
40%) in concrete mixture proportion of 1:2:4. The Test result showed that mixtures with
greater wood ash content require greater water content to achieve a reasonable
workability.

Udoeyo et al. (2006): studied the flexural strength development behavior of concrete
mixes produced with the use of wood waste ash as a partial cement replacement material
at varying levels of cement replacement; (0 (control concrete), 5, 10, 15, 20, 25 and 30%
binder weight. Flexural strengths of concrete specimens produced were recorded at 3, 7,
14, 21 and 28 days. Analysis of the results indicated that at all ages the concrete there

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was an increased level of cement replacement with wood waste ash that resulted in a
decreased magnitude of flexural strength. For instance, at 28 days, the flexural strength of
the concrete mix with 5% wood waste ash content was recorded at 5.20 MPa as compared
to 5.57 MPa of control concrete specimens. A gradual reduction occurred in the flexural
strength over 28 days. Results revealed a decrease from 5.20 MPa with 5% wood waste
ash concrete to 3.74 MPa with 30% total binder mass with wood waste ash content in the
mix was observed. By performing a regression analysis of flexural strength and
compressive strength data acquired, they also found a strong direct linear proportional
correlation between flexural strength and the compressive strength of wood waste ash
concrete mixes produced for up to 28 days as presented in the following equation.

Udoeyo et al. (2006) : evaluated the water absorption capacity of concrete made with
varying percentages (5, 10, 15, 20, 25, and 30% by weight of cement) of waste wood ash
. It can be seen that concrete specimens absorbed more water as the ash content
increased. The water absorption at 5% WWA content was 0.4% and increased to 1.05%
at 30% WWA content. However, these values are less than 10% which is the percentage
water absorption value accepted for most construction materials.

Ghorpade, V. G. (2012): stated that the effect of addition of wood waste ash (0-30%) in
concrete. The compressive strength and tensile strengths of wood ash concrete was
evaluated by conducting laboratory experimentation. The results obtained were compared
with reference to M30 grade concrete and he concluded that wood waste ash can be
effectively used in higher grade concrete also up to 10% by weight of cement.

Barathan, S., & Gobinath, B. (2013): stated that Wood ash limited to the grain size of
less than 75 micrometers is added to cement by weight percentage of 10%, 20% and 30%
by the method of replacement by weight. Finally, they conclude that the wood ash
exhibits an appreciable amount of pozzolanic properties up to a 10% replacement of
wooden ash.

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Muluken Negaw, Butula Buba (2017) graduated civil engineering students investigate
the effect of wooden ash as partial replacement of cement. The replacement was done for
5%, 10%, 15%, and 20% wood ash by weight.in this investigation workability,
compressive strength and flexural strength tests are conducted. The optimum
recommended value of the research is 10%.

Various investigations reached on conclusions that it is possible to use wooden ash as a

partial replacement of cement for concrete production. Averagely 10%-15% of wood ash
replacement gives better results. Most of the investigation was done with wood ash by
which passes through 150µm sieve sizes, since this is courser than cement (75µm) its
function may change from binding agent to filler material. Type of trees from which
wood ash collected may also affect the pozzolanic properties of ash.

This investigation fills those gaps using wood ash from one species specially eucalyptus
wood ash and sieving it through 75µm sieve size, as the ash is finer its surface area
increases so the rate of hydration become high and contributes to increasing the concrete
strength.

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CHAPTER THREE

RESEARCH METHODOLOGY

3.1 Introduction

This chapter deals with the methodology of the research. The research involves a wide
range review of literature related to the theme of study; issues dealing with the research
design, experiment analysis, the use of quantitative data for analysis of results, ethical
considerations, and expected outcomes; and results are reflected.

Figure 1.Flow chart

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3.2 Materials and test methods

The materials that have used in the study are Cement, Coarse Aggregate, fine aggregate,
Water and Replacement of eucalyptus wooden ash.

Figure 2.Concrete ingredients

3.2.1 Cement

In a general sense of the word, Cements are materials with adhesive and cohesive
properties, which make them capable of uniting or bonding together fragments or
particles of solid matter into a compact whole. In this study ordinary Portland cement
(OPC) grade 42.5 MPa has been used.

Specific gravity (ASTM C-128)

The density of cement is used in the calculation of the total aggregate content and of the
concrete density. It this study uses the following apparatus Le Chatelier’s Flask – The
standard flask is circular in cross section and dimensions conform essentially.

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There shall be a space of 10mm between the highest graduation mark and the lowest
point of grinding for the glass stopper, Kerosene, free of water, or naphtha.

As a formation of the study uses following procedure;

(1). Fill the flask with two liquids to a point on the stem between the 0 and the 1 ml mark.

(2) Dry the inside of the flask above the level of the liquid, if necessary, after pouring,
Record the first reading after the flask has been immersed in the water bath. The bath
shall maintain the temperature of the water constant ~for sufficient period of time to
avoid flask temperature variations greater than 0.2°C between the initial and final
readings, Introduce a quantity of cement for weighed to the nearest 0.05 g, in small
increments at the same temperature as the liquid. A vibrating apparatus used to accelerate
the introduction of the cement into the flask and to prevent the cement from sticking to
the neck. Place the stopper in the flask and roll the flask in an inclined position, or gently
whirl it in a horizontal circle, so as to free the cement from air until no further air bubbles
rise to the surface of the liquid. If a proper amount of cement has been added, the level of
the liquid will be in its final position at some point of the upper series of graduations and
Take the final reading after the flask has been immersed in the water bath.

Final the difference between the first and the final reading represents the volume of liquid
displaced by the mass of cement used in the test.

3.2.2. Coarse Aggregate

Coarse aggregate was obtained from quarries (crushed aggregate). According to the
Ethiopian Standard coarse aggregates are those between 75 and 4.75 mm in size. Gravel,
crushed rock and blast furnace slag are generally used as aggregates. The grading curve
of the aggregate is given in Table5 below, and the specific gravity of the aggregate was
2.68 and the other parameters given below with the figures.

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(i). Specific Gravity and Absorption Capacity of Coarse Aggregates (ASTM C-127)

The specific gravity of a substance is the ratio between the weight of the substance and
that of the same volume of water. The test is conducted by washing aggregate to remove
dust from the surface of the particles and dry the sample to constant weight and cool in
air for 1 hrs. And then immerse in water at room temperature for a period of 24hrs.
Remove the sample from the water and roll in a large absorbent cloth and Weigh the
sample in the saturated-surface-dry condition and record (B).then Immediately place the
saturated-surface-dry sample in the sample container and determine its weight in water
and record (C).After than dry the sample and cool in air and weigh (A).

Table 3 Specific Gravity of Coarse Aggregate

Sample Weight of B(gm) C(gm) SPEC.GR Average

sample(gm)A
1 341 344.8 216 2.65
2 438 443.2 282 2.72 2.68
3 466 472.2 298 2.68

Sample calculation

Specific gravity= A / (B-C)

Specific gravity =

= 2.65

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Where: -

A- Weight sample in air.

B- Weight of SSD sample in air.
C- Weight of oven dry sample in air.
The specific gravity of most normal weight aggregates will range from 2.4 to 2.9 from
the table specific gravity of aggregate is 2.68 tables 5. Since this value in the
recommended boundary the aggregate is good for mix in normal concrete.

(ii). Grain size distribution of coarse aggregate (ASTM C-136)

This test is performed to determine the percentage of different grain sizes of aggregate.
The mechanical or sieve analysis is performed to determine the distribution of the
coarser, larger-sized particles, and the method is used to determine the well graded
particles

Table 4 Grain Size Distribution of Coarse Aggregate

sieve weight of Percentage Percentage minimum % Max

opening retained(gm.) retained (%) passing (%) passing passing
(%)
75 0 0 100 100 100
37.5 0 0 100 100 100
19 1144 57.2 42.8 40 60
9.5 723 36.15 6.65 5 40
4.75 104 5.2 1.45 0 10
Pan 29 1.45 0 _ _
Total 2000

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Gradation curve
120

percentage of passing 100

80

60 %passing
40 minimu

20 maximu

0
1 10 100

Seive opennig

Figure 3. Gradation curve for coarse aggregate

Sample calculation

Percentage retained = (A/B) * 100 Where A= weight retained

B= total sample weight

Sieve opening for 19mm

Percentage retained = (1144/2000)*100 = 57.2
Sieve opening for 9.5mm
Percentage retained = (723/2000)*100 = 36.15
Percentage passing = 100 – cumulative percentage retained
Sieve opening for 19mm
Percentage passing = 100 - (0+0+57.2) = 42.8
Sieve opening for 9.5mm
Percentage passing = 100 – (0+0+57.2+36.15) = 6.65
The Particle size distribution of coarse aggregate is in the specified limit. So no need of
adjustment .Therefore the material is well graded aggregates.

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(iii). Absorption capacity of coarse aggregate

Table 5 Absorption Capacity of Coarse Aggregate

Average. absorption
Sample SSD OD Absorption capacity Capacity.
1 344.8 341 1.11
2 443.2 438 1.19 1.21
3 472.2 466 1.33

Sample calculation

Absorption capacity=

= = 1.1%

Where: - SSD –weight of saturated surface dry sample

OD- weight of oven dry sample

These absorption capacities indicate the porosity of aggregate to absorb water under
moisture. The moisture capacity of aggregate is 1.1% for sample indicated in table 5. The
absorption capacity is to minimum which indicate that the aggregate has less porosity.

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Table 6 Bulk Density of Coarse Aggregate

Sample Aggregate + Volume of Weight Net Bulk Average

cylinder(gm) cylinder(m3) cylinder(gm) weight density in

1 23281 0.01 7715 15566 1556.6

2 23240 0.01 7715 15525 1552.5 1556

3 23292 0.01 7715 15577 1557.7

Sample calculation

Bulk density =

=1556.6kg/m3

There are different types of aggregate used for concrete production. From those type of
aggregate crushed stone aggregate provided for mix with density of 1556 as shown in

the table. the recommended bulk density of the normal weight aggregate is within the
range of 1200-1760 as shown in the table 6 the value obtained in the test is within the

recommended range of normal weight aggregate.

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3.2.3 Fine Aggregate (Sand)

Test done to control the quality of sand used includes: sieve analysis of fine aggregate,
specific gravity and absorption capacity of sand, silt content and bulking of sand.

i. Sieve analysis for fine aggregate

Sieve analysis if fine aggregate is an experiment to determine the size o particle

distribution in fine aggregate by sieving it. The objective is to obtain curve of fine
aggregate. To determine the suitability of the tested fine aggregates concrete material, the
fine modulus of the fine aggregate is determined. According to the requirements of
ASTM-C33, the fineness modulus must not be less than 2.3 or more than 3.1. The
apparatus used are balance, standard sieve and sieve shaker. The test procedure is as per
ASTM-C33 (AASTHO M6).

Gradation for fine aggregate

Sample Calculation

C = A-B =375-370 = 5.0

D * 100 =5/501 * 100 =1.0

H =100 -D =100 - 1 = 99

Where A=Weight of sample and sieve,

B=weight of sieve,

C =weight of Retained

D =percentage Retained,

E =cumulative percentage retained, F=Percentage passing

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G =Total weight of Retained, H =Percentage passing

Table 7 Gradation for fine aggregate

cumulative percentage
weight of sample and

weight of Retained
weight of sieve

max % passing
min % passing
sieve opening

%Retained

%Passing
retain
sieve

9.5 375 370 5.00 1.00 1.00 99.00 100 100

4.75 427 405 22.00 4.39 5.39 94.61 95 100
2.36 366 339 27.00 5.39 10.78 89.22 80 100
1.18 428 337 91.00 18.16 28.94 71.06 50 85
0.6 475 316 159.00 31.74 60.68 39.32 25 60
0.3 467 326 141.00 28.14 88.82 11.18 5 30
0.15 345 299 46.00 9.18 98.00 1.99 0 10
0.075 319 311 8.00 1.60 99.60 0.40 0 3
Pan 226 224 2.00 0.40 100.00 0.00
500.00
Total 393.21
FM 3.93

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Gradation of fine aggregate

120.00

percentage passing in%

100.00

80.00

60.00

40.00

20.00

0.00
0.075 0.15 0.3 0.6 1.18 2.36 4.75 9.5
sieve size in mm
sample minimum % passing maximum %passing

.Figure 4.Gradation curve for fine aggregate

As the gradation graph shows the sand used for this research was well graded, it satisfies
the upper and lower limit of grain sizes based on ASTM C-128 recommendation.

ii. Specific gravity and absorption capacity of sand

This test used to determine the average density of a quantity of fine aggregate particles,
specific gravity and the absorption of the fine aggregate. The oven dry density and oven
dry specific gravity are determined after drying sand. The saturated surface dry specific
gravity and absorption are determined after soaking the aggregate in water for 24 hours.
Test is done as per ASTM C-128.

Sample calculation: - Bulk specific gravity (SSD) Basis

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Table 8 Bulk specific gravity on saturated surface dry

Sample Weight Weight Weight Bulk Average

of pycnometer+water(B) pynometer+water+sample(C) specific
sample gravity on
saturated
surface dry

1 500 1303.1 1608.3 2.57

2 500 1303.1 1613.4 2.64 2.61

3 500 1303.1 1613 2.63

As per ASTM C-128 recommendation the specific gravity of fine aggregate around
2.65.from table specific gravity 2.61. The sand is good for the mix.

iii. Apparent specific gravity

Sample calculation

Apparent specific gravity

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Table 9 Apparent specific gravity

Weight of
Weight of Weight Apparent
sample Weight
Sample oven dry pycnometer Specific Average
pycnometer(B)
sample(gm)(A) +sample water gravity
(SSD)
1 500 482 1303.1 1608.3 2.73
2 500 487 1303.1 1613.4 2.76 2.75
3 500 486 1303.1 1613 2.76

Table 10 Absorption capacity

Sample Weight Weight of Weight of Weight of Absorption Average

of oven dry pycnometer pycnometer+sample capacity (%)
sample sample(gm.)

1 500 482 1303.1 1608.3 3.73

2 500 487 1303.1 1613.4 2.67 3.09

3 500 486 1303.1 1613 2.88

As per ASTM C-136 Recommends that absorption capacity of fine aggregate is 3- 4 %

.Therefore from the table 10 the result show selected sand satisfies recommended values.

iv. Bulk density of sand

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Sample calculation

Table 11 Bulk density of sand

sample Volume of Weight of Bulk Average

cylinder(m3) sample(kg) density(kg/m3)

1 0.01 15.21 1521

2 0.01 14.81 1481 1521

3 0.01 15.61 1561

As per ASTM C-29 the approximate bulk density of sand that is commonly used in
normal weight concrete is between 1520-1680 Kg/m3. Since the bulk density of sand
1521 Kg/m3 which is between recommended value.

v. Water content of sand

W%= *100%

Where

A=Weight of original sample (gm)

B=Weight of oven dry sample (gm)

W%=water content in percent

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Sample calculation

Table 12 Water content of sand

Test
sample A in (gm.) B in (gm.) W% Average w%
1 500 499 0.20
2 502.5 498.5 0.80 0.47
3 497.5 495.5 0.40

For construction purpose moisture content less than 5% is preferable. Since the moisture
of sand 0.2%. It is appropriate for concrete production.

vi. Silt content

The objective of the test is to determine the silt content in sand. This test should not be
used for crushed rock sands. According to the Ethiopian Standard it is recommended to
wash the sand or reject if the silt content exceeds a value of 6%.

Apparatus used in this test includes: graduated cylinder or any glass jar, dish for taking
sample of sand, small size spoon, sample sand, funnel and clean water.

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Silt content (%) = *100,

Where:

A-amount of silt deposited above the sand and

B -amount of clean sand.

Figure 5. Silt content test specimen

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Table 13 Silt content of sand

Sample A B Silt content Average silt

content (%)
1 2 74 2.70
2 4.5 70 6.43
4.47
3 3 70 4.29

According to the Ethiopian Standard it is recommended to wash the sand or reject if

the silt content exceeds a value of 6%.The result is acceptable since 4.47% is less than
maximum recommended value.

vii. Bulking of sand

The objective of this test is to determine the amount of surface moisture in fine aggregate
by displacement in water. The apparent increase in volume of sand due to surface
moisture is technically known as bulking of sand. It has to be determined in laboratory or
on site to calculate the correct volume of sand at hand. Apparatus used for the test
includes: graduated cylinder, sample of sand and small size spoon.

Bulking (%) = *100 where A = volume of partial saturated sand and

B = volume of fully saturated sand.

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Figure 6.Bulking sand test specimen

Sample calculation

Table 14 Bulking of Sand Test

Bulking of Sand Test

A B A-B Bulking of sand (%)
404 390 14 3.59
396 384 12 3.13
392 387 5 1.29
Average bulking of sand 2.67

Excessive presence of moisture content in the sand makes the concrete to less durable and
loss its strength. As per IS2386-3 recommendation for less than 2% moisture content
bulking of sand 15%.From table the bulking of sand 2.67%.The sand recommended for
construction work since it has less bulking.

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3.3 Concrete mix design

The following mix design procedure is based on the ACI manual of concrete of concrete
practice standard ACI 211.1-91, using metric units. For normal weight aggregate. Mix
design tables are attached in the appendix-I.

Step- 1 From Table 1-1a, slump allowed is 25-100mm for building column, beam and
reinforced walls.

Step -2 Maximum aggregate sizes is 37.5mm obtained from sieve analysis result. It is the
sieve size >=90% of aggregate passes through.

Step- 3 From Table 1-1b, mixing water required is 166 kg/m3 for 25-50mm slump.

Step -4 Maximum W/C ratio for strength for non-air entrained concrete is 0.62 (Table
1-4a) and is 0.45 for exposure (Table 1-4b). Use the smaller value 0.45.

Step-5 Cement content= water requires (step-3) / (W/C) =166/0.45=368.89kg/m3.

Step-6 from Table 1-3a, volume of dry-rodded CA per unit volume of concrete is 0.69
depending on its fineness modulus.

Step -7 Materials per m3 considered (Estimation only as variation in aggregate densities

and water absorption not considered) for estimation of FA content

CA = 0.69* 1556 =1073.36 kg

Water = 166 kg

Cement = 368.89 kg

Total =1608.25 kg

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Volume of coarse aggregate m3 2.71 is specific gravity of

Coarse aggregate.

Volume of cement m3 3.1555 is specific gravity of cement.

Volume of water m3

Assumed volume of air is 4.5% or 0.045m3 by volume.

Volume of total aggregate=1-(0.1169+0.166+0.045) =0.6721 m3

Now volume of FA=0.6721-0.3961=0.276 m3

Weight of fine aggregate =

Step 8 Adjustment

Fine aggregate

% of moisture content=

% of absorption capacity=

Coarse aggregate

% of moisture content=

% of absorption capacity=

Final mix design for 1m3 concrete mixes

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Table 15 Final mix design

Material Weight(kg)
Cement 368.89
Fine aggregate 720.36+3.53=723.89
Coarse aggregate 1073.36+1.5349=1074.9
Water 166+22.19+12.99-3.53-1.53=196.27

Step 9 Mix ratio calculations

Step -10 Make trial batches & conduct different tests to check its suitability to satisfy the
requirements, and by adding water during mixing if it dry’s. Then calculate the corrected
batch quantities.

The proportion of cement to eucalyptus wood ash varied with the different percentage of
replacement as follows.

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Table 16 proportion of cement to eucalyptus wood ash per m3 of concrete

Trial mix Cement Wood ash course fine aggregate Water in

content in(kg) aggregate(kg) in(kg) litter
in(kg)
MIX-1(0%) 368.89 0 1074.9 723.89 0.52
MIX-2(10%) 332 36.89 1074.9 723.89 0.54

MIX-3(15%) 313.56 55.33 1074.9 723.89 0.57

MIX-4(20%) 295.11 73.78 1074.9 723.89 0.6

MIX-5(25%) 276.67 92.22 1074.9 723.89 0.64

3.4 Concrete test

3.4.1 Fresh concrete test

Fresh concrete is the concrete which is taken immediately after mixing, meaning that the
concrete before the mix starts its initial setting stage. Different tests like workability,
consistency and other tests are conducted to determine properties of fresh concrete.
Under this study workability of concrete was checked by conducting slump test.

i. Slump test

The slump of each mixture was measured in accordance with ASTM C-143, “Standard
Test Method for Slump of Hydraulic Cement Concrete.” The test was carried out by
filling a mold, in the shape of a truncated cone, with concrete and then withdrawing the
mold. The amount by which the concrete subsides or 'slumps' is then measured as shown
in Figures. After the slump has been measured, the concrete is tapped gently on the side
to obtain an indication of the cohesion of the mix.

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Figure 7.Slump test

ii. Unit weight or density of fresh concrete

The mass per unit volume, i.e. density, of freshly mixed concrete is determined by a
simple test in which the mass of concrete in a container of known volume is measured.
The standard procedure for conducting this test is described in NZS 3112 Part 1, Section
4.Its principal application is the determination of the volume of concrete produced from a
given mass of materials. Thus, it can be used to determine the volume of concrete
delivered to major sites by weighing delivery. The unit weights of fresh concrete were
measured according to ASTM C-138, “Standard Test Method for Unit Weight.

3.4.2 Hardened concrete test

The major function of concrete in concrete structure is to carry compressive load. To

achieve this goal cement to water paste mixed with fine and coarse aggregate in proper
mix design. After proper mixing, the concrete mixed cure and harden up to it gain its
strength. There are two basic method of test for harden concrete. This method of testing
hardened concrete is destructive and non-destructive test.

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i. Compressive strength test

The compressive strength was investigated in the laboratory by using crushing machine.
Three samples were tested for each set of blocks and were tested at the age of 7, 14 and
28days of curing. The average compressive strength was determined by averaging the
corresponding compressive strength values.

The strength characteristics of 0%, 10%, 15%, 20% and 25% replaced concrete blocks
sample were compared with the control concrete block sample. The apparatus used for
conducting this test cubic mold (150x150x150mm), spatula, vibrator, mixer and
compressive testing machine. The test conducted for 7day, 14day and 28day using
compression testing machine. The compressive strength of concrete calculated as follow.

Strength of concrete =

Figure 8.Compressive strength test

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Non- destructive

Non-destructive testing is generally defined as not impairing the intended performance of

the element or member under test, and when applied to concrete is taken to include
methods which cause localized surface zone damage. the test under this are rebound
hammer test, ultrasonic pulls velocity test etc.

i. The rebound Hammer tests (ASTM C-805 )

The rebound hammer test is a non-destructive testing method of concrete, which provide
a convenient and rapid indication of the compressive strength of the concrete. The
hammer weighs about 1.8kg and is suitable for both in laboratory and in field.

The objective of the test is to determine the compressive strength of the concrete by
relating the rebound index and the compressive strength, to assess the uniformity of the
concrete, to assess the quality of the concrete based on the standard specification and to
relate one concrete element with other in terms of quality.

The operation of rebound hammer is when the plunger of rebound hammer is pressed
against the surface of concrete, a spring-controlled mass with a constant energy is made
to hit concrete surface to rebound back. This extent of rebound on a graduated scale is
measured value is designated as rebound number or a rebound index.

The test conducted by holding the instrument in apposition that allows the plunger to
strike perpendicular to the surface of the sample test. Until the hammer impacted, the
pressures increase gradually. The test taken to ten times in a region 25mm closer between
the impacted point .After the hammer impact, the rebound number recorded in two
significant digits. The test of rebound hammer taken at 40-day curing time. Due to the
lack of material and insufficient time to test at 40 days the test was conducted in 28-day
curing time.

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Figure 9.Rebound hammer test

ii. Ultrasonic Pulse Velocity (UPV) test (ASTM)

It is in-situ, non-destructive test to check the quality of concrete .in this test, the strength
and quality of concrete is assessed by measuring the velocity of an ultrasonic pulse
passing through a concrete structure.

A higher velocity indicates good quality and continuity of the material, while slower
velocities may concrete with many cracks or voids.

Ultrasonic testing equipment includes a pulse generation circuit, consisting of electronic

circuit for generating pulses and a transducer for transforming electronic pulse into
mechanical pulse having an oscillation frequency in range. Ultrasonic pulse velocity can
be used to evaluate the quality and homogeneity of concrete materials, predict the
strength of concrete, evaluate dynamic modulus of elasticity of concrete and estimate the
depth of cracks in concrete. The test preformed above the curing of 40days and putting in
dry condition about three day.

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Calculate the pulse velocity as follows:

V=L/T

Where: V= pulse velocity, m/s

L= distance between transducers, m

T = effective transmit time, s

Figure 10.Ultrasonic pulse velocity test

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CHAPTER FOUR

RESULTS AND DISCUSSION

About 45 cubes were casted with C-25 grade of concrete. The 0%, 10%, 15%, 20% and
25% of cement was replaced by eucalyptus wood ash. Workability of fresh concrete,
compressive strength, unit weight of fresh and hardened concrete was tested. The result
and their comparisons are noted in tables and graphs. The tests for hardened concrete
were conducted for 7day, 14day and 28days.

4.1 Fresh concrete test result and discussion

4.1.1 Slump test

Table 17 Slump test result
Ash %age 0% 10% 15% 20% 25%
Slump in mm 56 54.5 52.5 51.5 50

Slump test graph

58
slump height in mm

56 56
54 54.5
52 52.5
51.5
slump height in
50 50
mm
48
0% 10% 20% 30%
percentage of Eucalyptus ash
partial repacement

Figure 11. Slump height versus eucalyptus ash graph

In the study, workability of concrete specimens with eucalyptus wood ash checked
through slump test.

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As the result shows that the value obtained from slump decreased with increase in
cement replacement with wood ash (0%,10%,15%,20%,25%). A typical plot using the
data from the work is shown in above figure 11.
In the other words, the material becomes less workable turning into harsh mixes with
increased content of wood ash, and thus requires higher water content to maintain its
workability. Finally, we conclude that the higher water content to attain a reasonable
workability may be due to the relatively high carbon content in wooden ash.

4.1.2 Unit weight or Density of fresh concrete

Table 18 Density of fresh concrete

% /ash by weight 0 10 15 20 25
Average density in 2.60 2.48 2.52 2.56 2.50
gm/cm3

Average density in gm/cm3

2.62
2.6
Density in gm/cm^3

2.58
2.56
2.54
2.52 Average density in gm/cm^3
2.5
2.48
2.46
0% 5% 10% 15% 20% 25% 30%
% of Ash by weight

Figure 12.Fresh concrete density diagram

As result shows density of fresh concrete decrease with partial replacement of eucalyptus
wooden ash with respect to control mix. However 20% replacement gives optimum fresh
concrete density from 10%, 15%,20% and 25% eucalyptus wooden ash replacement.
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4.2 Hardened concrete test result and discussion

4.2.1 Unit weight of hardened concrete

Table 19 Density of hardened concrete

% ash by weight 0 10 15 20 25

Average density in 2.55 2.38 2.43 2.50 2.40

gm/cm3

Average density in gm/cm3

2.56
2.54
2.52
2.50
Density in gm/cm3

2.48
2.46
2.44
Average density in
gm/cm^3
2.42
2.40
2.38
2.36
0% 5% 10% 15% 20% 25% 30%
% Ash by weight

Figure 13. Harden concrete density diagram

As the above result shows the density of hardened concrete without partial replacement
of wood ash gives 2.55kg/ .for partially replaced hardened concrete the density
increases for 10%-20% replacement, from 2.38kg/ to 2.50kg/ and decreased to
2.40kg/ for 25% replacement of ash.

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This indicates that as percentage of ash increase the density of concrete decrease as
compared to normal concrete but increase relative to each other up to the maximum value
of replacement. See appendix-II, Page 70

Table 20 Summary of concrete density

density of fresh density of hardened

% of ash by weight concrete in gm/cm^3 concrete in gm/cm^3

0% 2.6 2.55
10% 2.48 2.38
15% 2.52 2.43
20% 2.56 2.5
25% 2.5 2.4

Summary of density for fresh and hardened concrete

2.65
Density in gm/cm^3

2.6
2.55
2.5 density of fresh concrete
2.45
density of hardened
2.4
concrete
2.35
0% 10% 20% 30%
% of Ash by weight

Figure 14. Summary for density of concrete

The above graph indicates density of fresh and hardened concrete decreases as percentage
of wood ash increases. Density of fresh concrete is greater than its hardened density this
indicates that for fresh concrete the water used for mix design increases the weight of the
concrete.
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4.2.2 Compressive Strength test result

See appendix- II, Page 71-73

Table 21 Compressive Strength test result

% of Ash by
weight Curing Time Average compressive strength in Mpa
0 28.87
10 23.87
15 7day 24.27
20 25.02
25 20.87
% ash by
weight Curing time Compressive strength in Mpa
0 30.93
10 25.73
15 14day 25.74
20 26.93
25 24.6
% ash by
weight Curing time Compressive strength in Mpa
0 32.87
10 28.5
15 28day 29.5
20 30.87
25 26.33

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7day compressive strength

35

Compressive strength in Mpa

30
25
20
15 compressive strength
in Mpa
10
5
0
0 10 20 30
% ash by weight

Figure 15. Compressive strength of 7days

From the figure 7day compressive strength of concrete decreases by

17.32%,15.93%,13.34% and 27.71% within replacing of 10%,15%,20%,and 25%ash by
weight respectively with respect to pure(0% ash) concrete compressive strength. This
shows that optimum percentage of eucalyptus ash by weight replacement is 20%
eucalyptus ash.

14day compressive strength

40
Compressive strength in

30
20
compressive
Mpa

10 strength in Mpa
0
0 10 20 30
% of ash by weight

Figure 16. Compressive strength of 14 days

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From the above figure 14day compressive strength of concrete decreases by 16.81%,
16.78%, 12.92% and 20.47% within replacing of 10%, 15%, 20%, and 25% ash by
weight respectively with respect to pure(0%ash) concrete compressive strength. This
shows that optimum percentage of eucalyptus ash by weight replacement is 20%
eucalyptus ash.

28day comressive strength

35
Compressive strength in Mpa

30
25
20
15
10 compressive
5 strength in Mpa
0
0 10 20 30
% of Ash by weight

Figure 17. Compressive strength of 28 days

From the figure 28day compressive strength of concrete decreases by

13.29%,10.25%,6.08% and 19.90% within replacing of 10%,15%,20%,and 25%ash by
weight respectively with respect to pure(0% ash) concrete compressive strength. This
shows that optimum percentage of eucalyptus ash by weight replacement is 20%
eucalyptus ash.

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Table 22 Summary for compressive strength

Compressive strength in Mpa
% Ash by weight 7day 14day 28day
0% 28.87 30.93 32.87
10% 23.87 25.73 28.5
15% 24.27 25.74 29.5
20% 25.02 26.93 30.87
25% 20.87 24.6 26.33

Summury of 7day,14day and 28day compressive strength

35
Compressive strenght in Mpa

30
25
20
7day
15
14day
10
28day
5
0
0% 5% 10% 15% 20% 25% 30%
% of Ash by weight

Figure 18. Summary of Compressive strength

The graph shows that comparison of compressive strength of 0%, 10%.15%, 20% and
25% of eucalyptus wood ash by weight with respect to 7day, 14day and 28day curing
time.

The trend observed in the above graph is most probably due to the mechanisms that
eucalyptus wood ash particles act as filler and binding materials initially. As content of
ash increases the binding property increases up to optimum value, beyond this limit the
wood ash particle act more like filler material within the cement paste matrix than as

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binder material. And also results in increased surface area of filler material to be bonded
by decreasing the amount of cement which caused a decline in strength. And also the
concrete loses its cohesive properties resulted in decreased compressive strength.

4.2.3 Rebound Hammer test result

The rebound hammer is principally a surface hardness tester. It works on the principle
that the rebound of an elastic mass depends on the hardness of the surface against which
the mass impinges. See appendix-II, Page 72 and 73.

Table 23 Summary for rebound hammer test result

% of Ash by weight 28 day RH compressive strength in Mpa

0% 27.13
10% 19.90
15% 20.57
20% 20.71
25% 15.35

Rebound hammer compressive strenght

30
Compressive strength in Mpa

25

20

15

10
28 day RH compressive
5 strength in Mpa

0
0% 10% 20% 30%
% of Ash by weight

Figure 19.Rebound hammer test

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As result shows the rebound compressive strength of the concrete decrease within
replacing of ash with respect to pure concrete. However,20% ash by weight replaced
cement is the optimum value which satisfy the standard requirement as per ASTM C-805.

4.2.4 Ultrasonic pulse velocity test result

Table 24 Ultrasonic pulse velocity test result

% replaced UPLS velocity (m/s)

0% 3693.98
10% 3532.39
15% 3554.78
20% 3589.59
25% 3488.99

UPLS velocity (m/s)

3750.00
UPLS velocity in m/s

3700.00
3650.00
3600.00
3550.00 UPLS velocity (m/s)
3500.00
3450.00
0% 10% 20% 30%
% Ash by weight

Figure 20. Ultrasonic pulse velocity test result

The figure shows that for the first 10% Ash by weight the pulse velocity of concrete is
linearly decreasing and after than increasing up to 20% of ash replacement and become
that it is decreasing.This shows that 20% eucalyptus wooden ash by weight is the
optimum. As result 20% wood ash replacement is high bonded and strength development
of wood ash concrete.

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CHAPTER FIVE

CONCLUSION AND RECOMMENDATIONS

5.1 Conclusion
The use of wooden ash in concrete helps to transform it from environmental concern to a
useful resource for the production of effective alternative cementing materials. Based on
the results and discussion of this investigation the following conclusion has been reached.

 As percentage of wooden ash increase the workability of concrete mix slightly

decreases.
 Incorporation of eucalyptus wood ash as partial replacement of cement
decreased the slump of concrete; decrease in slump indicates increase in water
absorption capacity.
 Incorporation of eucalyptus wood ash as a partial replacement cement decreases
the compressive strength of concrete.
 Compressive strength of wood ash concrete is found to be optimum at 20%
(30.87 N/mm2).
 Partial replacement of eucalyptus wood ash affects the density of fresh and
hardened concrete.
 Bulk density of concrete was observed to decrease with the increasing % age of
wood ash.

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5.2 Recommendations
Based on the results, discussions and conclusions, the following recommendations arise:
 From this investigation the potentials for wood ash to be used as structural
concrete constituent for the development of sustainable is not in doubt.
 Using appropriate dosage of super plasticizer could be used with wood ash to
maintain required workability.
 It could be possible to use the 20% replacement of wood ash by weight in a
structure, which has a concrete grade of C – 25.
 Further investigation shall be added to conclude the effects of wood ash on
concrete properties which are not covered in this paper like flexural strength,
tensile strength, durability, permeability, bending behavior and associated
properties like cracking and stiffness.
 Quantity and quality of wood ash may vary with many factors such as combustion
temperature, species of wood and combustion technology used. Hence proper
analysis of wood ash is important before its application in concrete.

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REFERENCES

1. ASTMC618. (1998). Specifications for coal fly ash and raw and calcind natural
pozzolan for use minearal admixture in concrete. Annual book of ASTM
standard.
2. Cheah, C. (2011). the implementation ofstructural grade concrete and mortar. An
overview resources,conversation and recycling., 1-8.e. (n.d.).
3. Elinwa AU, E. S. (2008). Assesing of fresh concrete property containing sawdust
ash . construction building material ..
4. Etiiegni L, c. A. (1991). Physical and chemical characterstic of wood ash.
5. Loo SV, k. (2003). hand book of biomass combustion and co firing.
6. M, A. (2006). Characterstics of wood ash/opc cncrete. wood ash as an effective
raw material for concrete.
7. Misshra MK, R. K. (1993). Wood ash composition as function of furance
temprature. Biomass Bioenergy .
8. Muluken Negaw, B. B. (2017). Partial replacement cement by wooden ash .
arbaminch university.
9. Rajamma R, B. R. (2009). Characterstic and use of biomass fly ash in cement
based materials. Hazard mater.
10. Siddique, R. (20012). Utilization of wood ash in concrete manifacturing.
Resource conservation and recycling.
11. TR, N. (2002). Demonstration of manufucturing technology for concrete
utilization of wood ash from wisconnsin departement of natural resource.
12. Udoeyo FF, D. P. (2002). Sawdust ash as concrete material.
13. Udoeyo FF, I. D. (2006). Potential of wood ash as additive in concrete.
14. Werther J, S. M. (2000). combustion of aggricultral residue. prog energy combust.

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APPENDIX I

Standard Mix design table

Table 1- 1a: Recommended slumps for various types of construction.

Range of Slump, mm*
Types of construction Minimum Maximum
Reinforced foundation walls and footings 20 80
Plain footings, caissons, & substructure walls 20 80
Beams and reinforced walls 20 100
Building columns 20 100
Pavements and slabs 20 80
Mass concrete 20 80

 The upper limit may be increased by 20mm for compaction made by hand.
Table 1- 1b: Approximate mixing water and air- content requirements.
Water Kg/m3, For Indicated Nominal Sizes of Aggregates ( mm)
Slump, mm 9.5 12.5 19 25 37.5 50 75 150
Non – Air –Entrained Concrete
20-50 207 199 190 179 166 154 130 113
80-100 228 216 205 193 181 169 145 124
150-180 242 118 216 202 190 178 160 -
Approximate 3 2.5 2 1.5 1 0.5 0.3 0.2
Entrapped air (%)
Air Entrained Concrete
20-50 181 175 168 160 150 142 122 107
80-100 202 193 184 175 165 157 133 119
150-180 216 205 197 184 174 166 145 -
Recommended air Content (%)

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Mild exposure* 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0
Moderate 6.0 5.5 5.0 4.5 4.5 4.0 3.5 3.0
exposure**
Severe 7.5 7.0 6.0 6.0 5.5 5.0 4.5 4.0
exposure888
Note:
* Where air entrainment is not required for durability.
* Where concrete will not be continually exposed to water before freezing or to de-icing
agents (Na & Ca Cl2).
* Where de-icing or similar agents are used or where concrete may be highly saturated before
freezing.

Table 1-2: First estimate of Mass of fresh concrete.

Nominal Maximum, Size of First Estimate of Concrete Unit Mass, Kg/m3

Aggregate, mm Non-Air Entrained Air-Entrained Concrete
Concrete
9.5 2285 2190
12.5 2315 2235
19 2355 2280
25 2375 2315
37.5 2420 2355
50 2445 2375
75 2465 2400
150 2505 2435

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Table 1-3a: Dry Bulk Volume of Coarse Aggregate per Unit Volume of Concrete

Nominal Bulk Volume of Dry- Rodded Coarse per Unit Volume of Concrete
Maximum Size 0 For Fineness modulus of Fine Aggregate (sand of:
Aggregate, mm 2.40 2.60 2.80 3.00
9.5 0.50 0.48 0.46 0.44
12.5 0.59 0.57 0.55 0.53
19 0.66 0.64 0.62 0.60
25 0.71 0.69 0.67 0.65
37.5 0.75 0.73 0.71 0.69
50 0.78 0.76 0.74 0.72
75 0.82 0.80 0.78 0.76
150 0.87 0.85 0.83 0.81

Table 1-3b: Factors to be applied to the volume of coarse aggregate calculated on the
basis of table 1-3a for mixes of consistency other than plastic.

Relative Factors for maximum size of aggregate (mm) of :

water 9.5 12.5 19 25 37.5
Consistency Slump
Content
(mm)
Extremely dry - 78 1.90 1.70 1.45 1.40 1.30
Very stiff - 83 1.60 1.45 1.30 1.25 1.25
Stiff 0-30 88 1.35 1.30 1.15 1.15 1.20
Stiff plastic 30-80 92 1.08 1.06 1.04 1.06 1.09
Plastic 80-130 100 1.00 1.00 1.00 1.00 1.00
(Reference)
Fluid 130-180 106 0.97 0.98 1.00 1.00 1.00

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Table 1-4a: Relation between W/C ratio & Compressive strength of concrete.

Compressive strength, 28 W/C Ratio (By Mass)

Days (MPa) Non- Air Entrained Concrete Air-Entrained Concrete
45 0.38 -
40 0.43 -
35 0.48 0.40
30 0.55 0.46
25 0.62 0.53
20 0.70 0.61
15 0.80 0.71
* Measured on standard cylinders (150mm.diam.& 300mm. height.)

Table 1-4b: Maximum W/C Ratios for Concrete in Severe Exposures.

Exposure conditions
Structure continuously or Structure exposed to
Type of Structure
frequently Wet &exposed seawater or sulphates
to Freezing & Thawing*
Thin sections (railings, curbs, sills,
ledges, Ornamental work) & 0.45 0.40**
section with less than 25mm, cover
over steel.
All other structures. 0.50 0.45**
 Air- entrained concrete should be used under all conditions involving severe
exposure.
 When Type II or type V cement is used, the maximum W/C ratio may be
increased by 0.05.

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APPENDIX II

Concrete Test Result

Table 1 Density of fresh concrete

For 0%

Sample weight(gm.) volume(cm3) density(gm./cm3) average density

1 8805 3375 2.61

2 8725 3375 2.59 2.60

3 8785 3375 2.60

For 10%

Sample weight(gm.) volume(cm3) density(gm./cm3) average density

1 8370 3375 2.48

2 8436 3375 2.50 2.48

3 8303 3375 2.46

For 15%

Sample weight(gm.) volume(cm3) density(gm./cm3) average density

1 8577 3375 2.54

2 8510 3375 2.52 2.52

3 8426 3375 2.50

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For 20%

Sample weight(gm.) volume(cm3) density(gm./cm3) average density

1 8562 3375 2.54

2 8643 3375 2.56 2.56

3 8690 3375 2.57

For 25%

Sample weight(gm.) volume(cm3) density(gm./cm3) average density

1 8435 3375 2.50

2 8341 3375 2.47 2.50

3 8495 3375 2.52

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Table 2 Density of harden concrete

For 0%
Sample weight(gm.) volume(cm3) density(gm./cm3) average density
1 8583 3375 2.54
2 8689 3375 2.57 2.55
3 8582 3375 2.54

For 10%
Sample Weight(gm.) Volume()cm3) Density(gm./cm3) Average density
1 8070 3375 2.39
2 8036 3375 2.38 2.38
3 8003 3375 2.37

For 15%
Sample Weight(gm.) Volume(cm3) Density(gm./cm3) Average
Density
1 8277 3375 2.45
2 8110 3375 2.40 2.43
3 8226 3375 2.44

For 20%
Sample weight(gm.) Volume density(gm./cm3) average density
(cm3)
1 8442 3375 2.50
2 8462 3375 2.51 2.50
3 8364 3375 2.48

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For 25%
sample weight(gm.) Volume density(gm./cm3) average
(cm3) density
1 8135 3375 2.41
2 8141 3375 2.41 2.40
3 8065 3375 2.39

Table 3 Compressive strength test result

For 0%

sample 7 Day 14 Day 28 Day

1 30.4 32.8 31
2 27.8 28 35.6
3 28.4 32 32
Avg.comp 28.87 30.93 32.87

For 10%

Sample 7 Day 14 Day 28 Day

1 25.2 25.6 28.61

2 22.8 25.2 28.47
3 23.6 26.4 28.43
Avg.comp 23.87 25.73 28.50

For 15%
sample 7 Day 14 Day 28 Day
1 26.4 28.4 28.6
2 23.6 25.62 29.5
3 22.8 23.2 30.4
Avg.comp 24.27 25.74 29.50

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For 20%

Sample 7 Day 14 Day 28 Day

1 26.8 28.8 31.4

2 23.4 26.4 30
3 24.86 25.6 31.2
Avg.comp 25.02 26.93 30.87

For 25%
sample 7 Day 14 Day 28 Day
1 22.803 23.8 25.2
2 22.003 24.6 26.1
3 17.803 25.4 27.7
Avg.comp 20.87 24.60 26.33

Table 4 Rebound Hammer test results

For 0%

Average of 10
Sample Result Average Result(ccs),N/mm2
rebound reading

1 37.7 28.3
2 35.3 25.8 27.13
3 34.5 27.3

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For 10%

Average of 10
Sample Result Average Result(ccs),N/mm2
rebound reading

1 28.1 19.35
2 28.8 20.8 19.90

3 29.5 19.55

For 15%

Average of 10
Sample Result Average Result(ccs),N/mm2
rebound reading

1 31 21
2 35.1 20.95 20.57
3 34.7 19.75

For 20%

Average of 10
Sample Result Average Result(ccs),N/mm2
rebound reading

1 29.2 21.037
2 30.9 21.003 20.71
3 29.1 20.086

For 25%

Average of 10
Sample Result Average Result(ccs),N/mm2
rebound reading
1 23.03 19.805
2 22.8 11.6 15.35
3 23.76 14.632

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Table 5 Ultrasonic pulse velocity test results

0% Ash replacement
No of Final
Calibration(µs) Result(µs) Velocity(m/sec) Vavg(m/sec)
trials result(µs)
Sample 1 1 38.2 39.2 3826.53
Sample 2 1 40.1 41.1 3649.64 3693.98
Sample 3 1 40.6 41.6 3605.77

For 15%
Calibratio Result(µs Final
No of trials Velocity(m/sec) Vavg(m/sec)
n(µs) ) result(µs)
1 0.3 41.2 41.5 3614.46
2 0.3 40.9 41.2 3640.78 3554.78
3 0.3 43.7 44 3409.09

For 20%

No of Final
Calibration(µs) Result(µs) Velocity(m/sec) Vavg(m/sec)
trials result(µs)

1 0.1 41.9 41.8 3504.67

2 0.1 41.2 41.1 3649.64 3589.59
3 0.1 41.6 41.5 3614.46

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For 25%
No of Final
Calibration(µs) Result(µs) Velocity(m/sec) Vavg(m/sec)
trials result(µs)
1 0.6 41.7 42.3 3546.10
2 0.6 43.1 43.7 3432.49 3488.99
3 0.6 42.4 43 3488.37

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