An Investigation on Processing and Properties of Recycle Aggregate Concrete

AN INVESTIGATION ON PROCESSING AND PROPERTIES OF
RECYCLE AGGREGATE CONCRETE
SUBMITTED BY
MOHAMMAD BELAYET HOSSAIN MOHAMMED ALAUDDIN
ID: 003-08-04 ID: 003-08-08
Supervised By
Engr. Amrita Das
Asst. Professor
DEPARTMENT OF CIVIL ENGINEERING
SOUTHERN UNIVERSITY BANGLADESH
This Thesis Paper is submitted to the Department of Civil Engineering, Southern
University Bangladesh, Chittagong in Partial Fulfillment of the Requirements for the
Degree of Bachelor of Science in Civil Engineering.

LETTER OF SUBMISSION
To
Engr. Amrita Das
Asst. Professor
Department of Civil Engineering
Southern University Bangladesh (SUB)
Chittagong.
Subject: Letter regarding submission of thesis.
Dear Sir,
We, the undersigned have successfully completed our thesis on “An investigation on
processing and properties of recycle aggregate concrete”. We have completed all of
the practical works at University Laboratory during the period of the study on
above on strength of concrete with recycled aggregate. We have written this
report on our laboratory observation & practical investigation.
In this connection, we therefore hope that you would be kind enough to receive
this thesis paper and bless us heartily.
Yours faithfully
i) Mohammad Belayet Hossain ii) Mohammed Alauddin
ID No: 003-08-04 ID No: 003-08-08
B.Sc. in Civil Engineering B.Sc. in Civil Engineering
Southern University Bangladesh Southern University Bangladesh
iii

STUDENT’S DECLARATION
This thesis on “An investigation on processing and properties of recycle aggregate
concrete” is prepared by us. It is practical work, which is done at our university
laboratory. This is prepared for the partial fulfillment of the requirement for the
degree of Bachelor of Science in Civil Engineering, Southern University
Bangladesh. It is further ensured that the thesis has not been submitted to any other
Institute or University for obtaining any other of the degree and it is not
submitted for publication or fulfillment of any other purpose.
Yours faithfully,
i) Mohammad Belayet Hossain ii) Mohammed Alauddin
ID No: 003-08-04 ID No: 003-08-08
B.Sc. in Civil Engineering B.Sc. in Civil Engineering
Southern University, Bangladesh Southern University Bangladesh
iv

SOUTHERN UNIVERSITY BNAGLADESH
MEHEDIBAG, CHITTAGONG
CERTIFICATION OF APPRECIATION
This is to certify that the thesis entitled “An investigation on processing and
properties of recycle aggregate concrete” is submitted by Md. Belayet Hossain,
ID-003-08-04 and Mohammed Alauddin, ID-003-08-08 in partial fulfillment of
the requirements for the award of Bachelor of Science in Civil Engineering at the
SOUTHERN UNIVERSITY, BANGLADESH, It is an original piece of work on the
basis of (lab/ field) investigation and experimental data. I have gone through the
report very carefully. To the best of my knowledge, the matter embodied in this
thesis has not been submitted to any other University/ Institute for the award of any
degree or diploma.
I always tried my best to solve any problem regarding the thesis cordially. I have
gone through the report very carefully. In preparing this report they have
spared much time and efforts. Their thrust over seeking depth of every aspect
is quite satisfactory
With best regards,
Engr. Amrita Das
Asst. Professor
Department of Civil Engineering
SOUTHERN UNIVERSITY, BANGLADESH
Chittagong.
v

ACKNOWLEDGEMENT
First, the authors express the heartiest thanks and gratefulness to “Almighty Allah”
for His divine blessings, which made them complete this thesis successfully.
The authors would like to acknowledge their profound indebtedness to the
honorable thesis supervisor Engr. Ahsanul Islam, Lecturer, Dept. of Civil
Engineering, Southern University Bangladesh Again Engr. Amrita das Asst.
Professor Dept. of Civil Engineering, Southern University Bangladesh, who has
taken over the responsibility of their supervision but at the eleven hour he has gone
abroad for perusing higher study.
His endless patience, scholarly guidance, continued encouragement, constructive
criticism, a contribution of new ideas and constant supervision has made it possible
to complete the research work. Furthermore, the authors express their gratitude.
The authors would like to thank honorable Prof. Md. Mozammel Hoque, Adviser,
Dept. of Civil Engineering, Southern University Bangladesh, and honorable Prof.
Engr. M. Ali Ashraf PEng Pro-Vice Chancellor of the University & Head, Dept. of
Civil Engineering, Southern University Bangladesh, who encouraged us in carrying
out the project with all facilities of the department.
The authors would also like to convey gratitude to all Course Teachers’ here
method of whose teaching helped a lot to start and complete this thesis work.
Thanks are also extended to all the technical staff of the university laboratory.
29 OCTOBER 2016
SOUTHERN UNIVERSITY BANGLADESH. AUTHORS
vi

ABSTRACT
A significant amount of natural resource can be saved if the demolished concrete is
recycled for new construction. In addition to the saving of natural resources,
recycling of demolished concrete will also provide other benefits, such as the
creation of additional business opportunities, saving the cost of disposal, saving
money for local government and other purchasers’ etc. Recycled aggregate is
comprised of crushed, graded inorganic particles processed from the materials that
have been used in the constructions and demolition debris. The objective of this
thesis is to achieve the target strength of concrete by using recycle aggregates fully
or partially with the natural fresh stone. Local sand (FM value 1.83) is used as fine
aggregates. In this investigation, demolished concrete blocks were collected from
demolished head of the Pile and broken into pieces as aggregates were controlled as
per ASTM C33. Concrete cube specimens size (100 mm x 100 mm x 100 mm) were
made and tested for compressive strength test by Universal Testing Machine (UTM).
The workability of concrete was also measured by slump test. In this study, ACI
211-91 is used for mix design & conducted compressive strength test for 72 cubes
with different mix ratios. The test result shows that the maximum strength of
recycled aggregate concrete achieved 65%-84% of target strength.
Keyword: Recycle Aggregate, Fresh Aggregate, Concrete Compressive Strength
test, Slump test.
vii

TABLE OF CONTENTS
CHAPTER TITLE PAGE
Title Page i
Letter of submission ii
Student’s Declaration iii
Certification of Appreciation iv
Acknowledgement v
Abstract vi
Table of Contents vii
List of Figure ix
List of Table x
List of Symbols & Abbreviations xi
1. Introduction
1.1 Background of the study 1
1.2 Statement of the problems 2
1.3 Objective of the study 2
1.4 Scope of the study 2
2. Literature Review
2.1 Introduction 3
2.2 Summary 3
2.3 Implication of this research 4
2.4 How can recycled aggregate use? 4
2.5 Present knowledge & gap in information 5
2.6 Why concrete recycling is necessary for Bangladesh? 5
2.7 Experimental investigation 6
2.8 Basic properties of recycled aggregate concrete 6
viii

3. Methodology
3.1 Concept 7
3.2 Experimental Methods 7
3.3 Research Program 8
4. Result and Discussion
4.1 General 9
4.2 Experimental Data 9
4.3 Graphical Representation 13
4.4 Discussion 16
5. Conclusion and Recommendation
5.1 Conclusion 17
5.2 Recommendation 17
6. Reference
7. Appendix
(A) The recommended values of ACI concrete mix design 211.1-91
(B) Fineness Modulus of Aggregate
(C) Unit Weight, Specific Gravity, Absorption Capacity, Moisture
Content of Aggregate
(D) ACI Concrete mix design 211.1-91
ix

LIST OF FIGURE
FIGURE TITLE PAGE
1.1 Research Program 8
4.3.1 Comparison of compressive strength of concrete for Recycle
Aggregate Concrete (RAC) and Fresh Aggregate Concrete (FAC)
between Curing Periods M 21 13
between Curing Periods M 28
13
between Curing Periods M 32
14
4.3.4 Comparison of compressive strength Gain % of concrete for Recycle
Aggregate Concrete (RAC) vs Fresh Aggregate Concrete (FAC)
M 21 14
M 28 15
M 32 15
x

LIST OF TABLE
TABLE TITLE PAGE
4.2.1 Fineness modulus of aggregate 09
4.2.2 Unit weight, specific gravity, absorption capacity, moisture content
of fine Aggregate 09
4.2.3 Unit weight, specific gravity, absorption capacity, moisture content
of coarse Aggregate 10
4.2.4 Recycle aggregate concrete mix design for concrete compressive
strength of M 21 (±3000 psi) 10
4.2.5 Concrete mix design ratio by (ACI-211.1-91) 12
4.2.6 Comparison of concrete compressive strength Recycle Aggregate
Concrete (RAC) vs. Fresh Aggregate Concrete (FAC) between
Curing Periods M 21 12
xi

LIST OF SYMBOLS AND ABBREVIATIONS
SUB Southern University Bangladesh
RAC Recycled Aggregate Concrete
FAC Fresh Aggregate Concrete
RA Recycle Aggregate
FM Fineness Modulus
FA Fine Aggregate
CA Coarse Aggregate
Aggr. Aggregate
Psi Pound per Square Inch
MPa Mega Pascal
N/mm2 Newton per square millimeter
W/C Water Cement Ratio
C Cement
W Water
UTM Universal Testing Machine
BNBC Bangladesh National Building Code
ACI American Concrete Institute
ASTM American Society for Testing and Materials
xii

CHAPTER 1
INTRODUCTION
1.1 Background of the Study
The generation of huge amounts of construction waste is anticipated due to the
demolition of older structures such as power stations built more than 30 years ago. On
the other hand, the reuse of construction waste is highly essential from the viewpoint of
Life Cycle Assessment (LCA) and effective recycling of construction resources. In
order to promote the reuse of construction waste, it is necessary to achieve three basic
concepts: (1) assurance of safety and quality, (2) decrease of environmental impact,
and (3) increase of cost effectiveness of construction. This paper outlines the
development of a recycling system, application of recycled aggregate concrete
produced by the aggregate replacing method, which is effective in reducing both cost
and environmental impact from the viewpoint of LCA for concrete waste generated by
the demolition of large-scale buildings such as powerhouses.
The Result of this study showed that recycled aggregate concrete using the aggregate
replacing method can acquire sufficient quality as structural concrete and/or precast
concrete products through material design based on the value of the relative quality
method. Moreover, with the adoption of the developed recycling system, it was
confirmed possible to recycle concrete waste produced from the demolition buildings
in a highly effective manner reducing both recycling cost and environmental impact.
Global Construction industry growth is substantial in size. Report by Global Insight,
predicts an increase in construction spending from 4800 billion US dollars in 2008 to
6200 billion US dollars in 2013. These figures indicate a tremendous growth in the
construction sector almost one and a half times in the coming 5 years. The construction
industry Worldwide is a conspicuous consumer of the raw material of many types and
thus large material inventories are required to sustain the growth. The raw materials
used in construction are largely naturally occurring and non-renewable resources hence
using these materials meticulously is the need of the time. Also proportionately related
are the issues of cost that is rising since material inventory is becoming scarce and
material has to be procured from distant places. Among the various raw materials used
in construction, aggregates are important components for all the construction activities
and the demand in 2007 has seen an increase by five percent, to over 21 billion tones,
the largest being in developing countries like China, India, etc. Keun- Hyeok Yang has
reported construction industry’s global requirement of natural aggregate Around 8 - 10
billion tons annually after the year 2010.
1

1.2 Statement of the problem
 Production and utilization of concrete are rapidly increasing the
consumption of natural aggregate as the largest concrete component.
 Generation of huge deposits of construction waste by demolition.
 By the recycling of the demolished concrete, the aforementioned
environmental problems caused by the aggregate consumption can be greatly
reduced.
 The disposal problems of the demolished concrete can be solved also.
For these reasons, felt that investigations are needed for recycling of demolished
concrete.
1.3 Objectives of the study
• To determine the compressive strength of concrete by using recycled aggregate.
• To compare the compressive strength of recycled and fresh aggregate concrete
by using different mix design and curing period.
1.4 Scope of the study
Recycled aggregate collected from demolished site and tests of the materials’ properties
such as specific gravity, bulk density, fineness modulus, moisture content, water
absorption capacity for both recycled and fresh aggregate as well as for fine aggregate
have been done.
Concrete mix design has been done as per ACI-211.1-91. Concrete compressive
strength test has been performed after the curing period of 7, 21, 28, 60 days.
2

CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Demolished concrete was crush to provide as new coarse aggregate. Recycle is the
reprocessing of wastes to recover an original raw material. Recycling Concrete is
becoming an increasingly popular way to utilize aggregate left behind when structures
are demolished. The results of an extensive experimental programmer aimed at
examining the performance of Portland cement concrete produced with Fresh coarse
and recycled coarse aggregates are reported in this paper. Then determine and analysis
the properties of recycling coarse aggregates and recycle coarse aggregate’s concrete.
Then compare their properties corresponding to fresh coarse aggregate and its concrete.
The effects of 100% recycled concrete coarse aggregate are used in the Portland cement
concrete. It is suitable for use in designed application.
Waste arising from construction and demolition constitutes one of the largest waste
streams in the world, of this a large proportion of potentially useful material disposed of
as landfill. When structures made of concrete are demolished or renewed, concrete
recycling is a progressively common method of consuming the rubble. Concrete was
once regularly truck to landfills for throwing away, but recycling devours a number of
aids that have made it a more attractive option in this age of greater conservational
awareness, more conservation rubrics, and the craving to keep construction costs down.
2.2 Summary
Concrete is the second most consumed material after water and it shapes our built
environment. Homes, schools, hospitals, offices, roads and runways all make use of
concrete. Concrete is extremely durable and can last for hundreds of years in many
applications. However, human needs change and waste are generated more than 900
million tons per annum in Europe, the US and Japan alone, with unknown quantities
elsewhere. Concrete recovery is achievable concrete can be crushed and reused an
aggregate in new projects.
Recycling or recovering concrete has two main advantages: (1) it reduces the use of
new virgin aggregate and the associated environmental costs of exploitation and
transportation and (2) it reduces unnecessary landfill of valuable materials that can be
recovering and redeployed.
The main objective of this report is to promote concrete recycling as an issue and
encourage thinking in this area. It provides some discussion of key issues without going
into significant technical details. The report ultimately promotes a goal of “zero
landfills” of concrete. With good initial planning and design, well-considered
renovation and managed demolition, sustainable development using concrete are
achievable. The report recommends that all players adopt sustainable thinking when it
comes to concrete. It also recommends a series of key indicators. There is a lack of
3

reliable and consistent statistics. Improved reporting coupled with clear objectives will
ultimately lead to improved performance and less concrete in landfills.
2.3 Implication of this research
Recycling or recovering concrete has two main advantages:
(a) To reduces the use of fresh aggregate and the associated environmental costs
of exploitation and transportation.
(b) To reduce unnecessary landfill of valuable materials that can be recover.
Other main advantages are:
 Reduction of waste, landfill or dumping, and associated site degradation
 Substitution for virgin resources and reduction in associated environmental costs
of natural resource exploitation
 Reduced transportation costs: concrete can often be recycled on demolition or
construction sites or close to urban areas where it will be reused
 Reduced disposal costs as landfill taxes and tip fees can be avoided
 Good performance for some applications due to good compaction and density
properties (for example, as road sub-base)
 In some instances, employment opportunities arise in the recycling industry that
would not otherwise exist in other sectors.
2.4 How can recycled aggregate be use?
a) Use as aggregate
1) As a coarse aggregate
- For road base, sub-base and civil engineering applications)
- For concrete
2) As a fine aggregate
- Leaching issues
b) Recycled aggregates can be use in a variety of construction applications as
illustrated below:
 Concrete road
 Deep foundations
 Bitumen road
 Hydraulically bound road
 Utilities reinstatement in roads
 Ground improvements
 Concrete substructures
 Concrete structures
 Buildings (both industrial and residential)
 Shallow foundations
4

2.5 Present knowledge & gap in information
 To avoid early deterioration of concrete structures, the durability design of the
structures to be taken into account.
 More research works on the durability of concrete structures are to be carried
out to understand deterioration process in our hot and humid country.
 The Quality of the cement brands is to be controlled for the sustainable
development of concrete construction works.
 With similar abrasion value, brick aggregate concrete gives higher strength
compared to the same with stone aggregate concrete.
 Concrete strength from 2,500 ~ 3,300 psi can be obtained using recycled coarse
aggregate.
 In the undergraduate program, more courses on concrete technology are to be
included.
 Skilled workers are to be produced through professional organizations.
 More seminars and symposium are to be arranged to discuss the knowledge
related to the sustainable development of concrete construction works in
Bangladesh.
2.6 Why concrete recycling is necessary for Bangladesh?
In Bangladesh, the volume of demolished concrete is increasing due to the deterioration
of concrete structure as well as the replacement of many low-rise building by relatively
high-rise building due to the booming of real estate business. Disposal of the
demolished concrete is becoming a great concern to the developers of the building. If
the demolished concrete is use for new construction, the disposal problem will be
solved, the demand for new aggregate will be reduced and finally consumption of the
natural resources for making aggregate will be reduced. In some project sites, it was
also found that a portion of the demolished concrete is used as aggregate (after breaking
into aggregate) in foundation work without any research on the recycled aggregate. In
most of the old building, brick chips were use as a coarse aggregate of concrete in
Bangladesh. Studies related to the recycling of demolished concrete are generally found
for stone chips made concrete. Therefore, investigations on recycling of brick made
demolished concrete are necessary.
The main causes of increasing the volume of demolished concrete in Bangladesh are as
follows:
 Demolished building sites.
 Again of one structure.
 Replacement of low rise building by relatively high-rise building.
 Early deterioration.
 Demolition of illegal construction.
5

 Building waste that may generate from natural calamities like Earthquake.
2.7 Experimental Investigation
The aim of this investigation is to compare the basic properties of controlled concrete
(concrete made with natural aggregate) and the properties of concrete made with
different contents of recycled aggregate.
Three concrete types were tested within the research program. Mixture proportions of
the tested concrete types were determined in accordance to the ACI 211.1-91.
2.8 Basic properties of recycled aggregate concrete
 Decreases of specific gravity.
 Decreases in bulk density.
 Increases of water absorption.
 Increases of abrasion loss.
 Increases of crushability.
 Increases quantity of dust particles.
 Increases quantity of organic impurities if concrete is mixed with earth
during building demolition.
Available test results of recycled aggregate concrete vary in wide limits, sometimes are
even opposite, but general conclusions about the properties of concrete with recycled
coarse aggregate compared to concrete with natural aggregate are approximate:
 Water absorption increases up to ±50%
 Decreases compressive strength up to ±30%
 Increases creep up to ±50%
 Decreases splitting and flexural tensile strength up to ±10%
 Decreases modulus of elasticity up to ±45%
 Same or decreased frost resistance
6

CHAPTER 3
METHODOLOGY
3.1 Concept
When recycled aggregate concrete is applied to buildings, road base etc., the quality
required is generally equivalent to natural aggregates such as gravel and sand.
3.2 Experimental Methods
The overall experimental program consisted of two stages: (1) a comprehensive study of
the properties of new concrete made with recycled aggregate that was prepared by
crushing partially hydrated old concrete; (2) a study of the effect of recycled fines only
on the properties of new concrete. This paper presents the results of stage 1 of the study.
Demolished concrete blocks were collected from the structural members of the
demolished buildings. The collected concrete samples were broken into pieces
mechanically in particular sizes as 5 mm to 20 mm which FM is 4.20. The aggregates
were tested for absorption capacity, specific gravity, moisture content, unit weight, and
FM. The specific gravity and absorption capacity are determined as per ASTM C128,
unit weight as per ASTM C29. The FM, water absorption and specific gravity of sand
used in this investigation were 1.83, 3.95%, and 2.55, respectively. After investigation
of aggregates, concrete cube specimen of size 100 mm x 100 mm x 100 mm in were
made for evaluation of compressive strength at 7, 21, 28 and 60 days as per ASTM C39.
W/C ratios of RAC were 0.65, 0.61 and 0.52. In addition, W/C ratio of FAC was 0.48,
0.45 and 0.39. Cement content of concrete was 185 kg/m3 as per ACI211.1-91 (Table-
6) for all cases. After mixing concrete, the workability of concrete was measured by
slump cone test. Then the specimens are cured under water continuously. The
compressive strength of concrete was measured at 7, 21, 28 and 60 days by using
Universal Testing Machine (UTM). The failure surfaces of concrete were also checked
carefully after crushing of the concrete cube. About 72 concrete cubes were
investigated for 6 cases as summarized in Figure 4.3.1.1 to 4.3.1.3.
7

3.3 Research Program
Figure 1.1 Research program of this thesis
8
MATERIALS COLLECTION
FRESH AGGREGATE DEMOLISHED AGGREGATE
FINE AGGREGATE CEMENT
TEST OF THE MATERIALS PROPERTIES
MIX DESIGNMIX DESIGN
MIX RATIO
CASTING AND CURING OF CUBES
COMPRESSIVE STRENGTH TEST
COMPARE AND EVALUATION
CONCLUSION

CHAPTER 4
RESULT AND DISCUSSION
4.1 General
Benefits of recycled aggregate (RA) in concrete can be described in environmental
protection and economical terms. The application of recycled aggregate in construction
activities has been practiced by developed countries and also of some Asian countries.
This paper reports the results of an experimental study on the mechanical properties of
recycled aggregate concrete (RAC) as compared to natural aggregate concrete (NAC).
The 100% of RA used in the concrete mix to replace the natural coarse aggregate in
concrete number 100 x 100 x 100 cube mm were cast with target compressive strength
is 21, 28 and 32 MPa within 7, 21, 28 and 60 days curing period.
4.2 Experimental Data
Table 4.2.1 Finesse Modulus of fine & coarse aggregate. (Appx. No: (B1-B5)
Fine Aggregate F.M
Local Sand 1.33
Sylhet Sand 2.34
Combined (Local & Sylhet) 1.83
Coarse Aggregate F.M
Recycled 4.20
Fresh 5.70
Table 4.2.2 Unit weight, specific gravity, absorption capacity, moisture content of
fine aggregate. (Appx. No: 4.3.1-4.3.2)
Fine
Aggregate
Unit Weight
(kg/m3)
Specific
Gravity
Absorption
Capacity, %
Moisture
Content, %
Local Sand 1606 2.55 3.95 2.70
Sylhet Sand 1500 2.54 3.09 2.06
9

Table 4.2.3 Unit weight, specific gravity, absorption capacity, moisture content of
course aggregate. (Appx. No: 4.3.3-4.3.4)
Coarse
Aggregate
Unit Weight
(kg/m3)
Specific
gravity
Absorption
capacity, %
Moisture
content, %
Recycled 1235 2.14 8.64 1.70
Fresh 1628 2.73 0.70 2.06
Table 4.2.4 Recycled Aggregate Concrete Mix Design for Concrete Compressive
Strength of M 21 (±3000 Psi) (Appx. No: 4.4.1-4.4.6)
Sample: Recycled Aggregate Concrete
Design Data,
Design Strength, (Fmin) = 21 MPa
Standard deviation, (S) = 4.5 {S value is taken from Table-8, P-24}
Specific Gravity of (F.A) = 2.54
Specific Gravity of (C.A) = 2.14
Unit wt. of (C.A) = 1235 kg/m3
Fineness Modulus of (F.M) = 1.83
Maximum Size of C.A = 20 mm
Slump value = 50 mm
Absorption Capacity of C.A = 8.64 %
Free surface Moisture in (F.A) = 2.38 %
(K) = 1.64 {K value is taken from Table-1, P-20}
Step-1: Mean Strength
F .m = F min + K S
= 21 + 1.64 x 4.5
= 28.81
=28 MPa
Step-2: Water /Cement Ratio
For Mean strength, f m = 28 MPa
W/C = 0.57 {From Table-3, P-20}
For Exposure = 0.50
Step-3: Amount of Water & Cement
Water content = 185 kg/m3 {From Table-6, P-23}
Cement content = kg/m3
10

= 370 kg/m3
Step-4: Volume of Coarse Aggregate
F.M of fine Aggregate = 1.83
Bulk Volume of C.A = 0.72 m3/m3 of Concrete
{From Table-2, P-20}
Step-5: Weight of Coarse Aggregate
Weight of coarse Aggr. = 0.72 x 1235
= 889.2 kg/m3 of Concrete
Step-6: Unit weight of Concrete
Unit weight of Concrete = 2355 kg/m3 {From Table-7, P-24}
Step-7: Resulting Amount of Materials
Weight of Water = 185 kg/m3
Weight of Cement = 370 kg/m3
Weight of C.A = 889 kg/m3
Weight of F.A = 2355-(185+370+889)
= 911 kg/m3
Step-8: Proportion
Materials = Cement: F.A: C.A: Water
= 370: 911: 889: 185
Ratio = 1: 2.46: 2.40: 0.50
Step-9: Proportion required for field application
Free Surface Moisture in F.A = = 21.68 kg
F.A in field application = 911 + 21.68 = 933 kg/m3
Water absorption by C.A = = 76.8 kg
Water in field application = 185+76.8-21.68 = 240 kg/m3
Step-10: Final Proportion
Materials = Cement: FA: CA: Water
= 370: 933: 889: 240
Ratio = C: FA: CA: W
= 1: 2.52: 2.4: 0.65
11

Table 4.2.5 Concrete mix design ratio by (ACI-211.1-91)
Using Recycled AggregateUsing Recycled Aggregate
StrengthStrength CementCement SandSand StoneStone W/CW/C
M 21M 21 (±3000 psi)(±3000 psi) 11 2.532.53 2.392.39 0.650.65
M 28M 28 (±4000 psi)(±4000 psi) 11 2.332.33 2.262.26 0.610.61
M 32M 32 (±4600 psi)(±4600 psi) 11 1.831.83 1.921.92 0.530.53
Using Fresh AggregateUsing Fresh Aggregate
StrengthStrength CementCement SandSand StoneStone W/CW/C
M 21M 21 (±3000 psi)(±3000 psi) 11 1.811.81 3.103.10 0.480.48
M 28M 28 (±4000 psi)(±4000 psi) 11 1.651.65 2.932.93 0.450.45
M 32M 32 (±4600 psi)(±4600 psi) 11 1.251.25 2.492.49 0.390.39
Table 4.2.6 Comparison of concrete compressive strength Recycle Aggregate Concrete
(RAC) vs. Fresh Aggregate Concrete (FAC) between Curing Periods M 21
Recycled vs Fresh Concrete Strength M-21 (±3000 psi)
Days Recycle (MPa) Fresh (MPa) Recycle (psi) Fresh (psi)
7 7.54 11.91 1093.10 1726.41
21 15.64 20.72 2267.64 3004.02
28 16.31 20.90 2364.92 3030.90
60 17.60 22.61 2551.47 3278.11
Recycled vs Fresh Concrete Strength M-28 (±4000 psi)
Days Recycle (MPa) Fresh (MPa) Recycle (Psi) Fresh (Psi)
7 11.16 16.02 1617.62 2322.68
21 17.78 23.04 2577.72 3340.51
28 17.95 27.69 2602.95 4014.74
60 19.60 28.23 2842.12 4094.03
Recycled vs Fresh Concrete Strength M 32 (±4600 psi)
Days Recycle (MPa) Fresh (MPa) Recycle (Psi) Fresh (Psi)
7 14.99 16.47 2173.26 2388.41
21 21.08 31.63 3056.93 4586.08
28 22.41 31.90 3249.92 4625.41
60 22.89 32.13 3319.63 4658.74
12

4.3 Graphical Representation
The whole experimental data and relevant calculated data are tabulated in the
following Fig. 4.3.1 to 4.3.6
Fig. 4.3.1 Comparison of concrete compressive strength Recycle Aggregate Concrete
13

Fig 4.3.4 Compressive Crushing Strength Gain % Recycle Aggregate Concrete (RAC)
vs. Fresh Aggregate Concrete (FAC) M 21
14

15

4.4 Discussion
 Concrete specimen made with the aggregate got from demolished concrete has
achieved 65-84% of the strength for which it has been supposed to be designed.
On the other hand, concrete prepared from fresh aggregate showed the better
performance regarding strength.
 Concrete made with 100% recycle aggregates was weaker than concrete made
with fresh aggregates at the same concrete mix design. Strength reduction was
20%-30% of design strength.
 The workability of RAC is lower than FAC because the rate of the absorption
capacity of RA is higher than FA.
16

CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
Based on the laboratory investigations, the following conclusions are made:
1. Concrete strength from 17.5 ~ 23.0 MPa can be obtained using recycled coarse
aggregate.
2. The water requirement for all the mixes is different and especially for mixing
with recycled coarse aggregates, so workability is poor then fresh aggregate
concrete.
3. The density of concrete is another important factor. The results indicated that all
the concrete mixes with recycled aggregate have less density as compared to
fresh aggregate concrete.
4. Recycled aggregate concrete is not suitable for high strength concrete.
5.2 Recommendation
Based on the laboratory investigations, the following recommendations are:
1. Recycled Aggregate concrete can be use low strength structure.
2. Further research can be done by super plasticizer then the result may be different
values.
3. Further research can be done by fresh aggregate are partially mix in recycled
aggregate then the result can be different.
17

REFERENCE
[1] Dr. Aziz, M.A, Ph.D., “Engineering Material” Book, 1st
Edition,1995.
[2] Dr. Tarek Uddin Mohammed, Associate Professor, Dept. of Civil Engineering
(UAP), “Sustainable Development of Concrete Technology”.
[3] Mr. Shimul Biswas, Asst. Professor, Dept. of Civil Engineering (CUET), “An
Investigation on Recycling of Demolished Concrete”
[4] M.S Shetty, “Concrete Technology”, Book, 5th
Edition, 2002. S. Chand And
Company Ltd.
[5] Alan, D.B., Recycled Concrete As Source of Aggregate, ACI Journal, American
Concrete Institute, Detroit, May 1977, Pp-212-219.
[6] Kikuchi M, Dosho Y, Narikawa M, Miura T. (1998). Application of recycled
aggregate concrete for structural concrete, part-I: the experimental study on the quality
of recycled aggregate and recycled aggregate concrete. Proceedings of the International
Conference on the Use of Recycled Concrete Aggregates. UK: Thomas Telford.
[7] Limbachiya M.C., Leelawat T, Dhir R.K. (2000). Use of recycled concrete
aggregate in high strength concrete. Mater Struct 33:574–80.
[8] Ryu J.S. (2002). An experimental study on the effect of recycled aggregate on
concrete properties, Mag. Concr. Res. 54 (1) 7– 12.
[9] Recycled Concrete Aggregate- A Value Aggregate Source For Concrete Pavements-
By James Trevor Smith, A Thesis Presented To The Degree of Doctor of Philosophy In
Civil Engineering Waterloo, Ontario, 2009.
[10] Effectiveness of Using Course Recycled Concrete Aggregate In Concrete, Neela
Deshpande Faculty of Engineering, Vishwakarma Institute of Information Technology,
Pune.
[11] Hansen, T.C. (1992), "Recycling of Demolished Concrete Masonry, Rilem Report
No. 6, E&FN Spon, London, Great Britain, pp. 316.
[12] British Standards Institution (2009). Tests for chemical properties of aggregates.
Chemical analysis. BS EN 1744-1 (2009).
[13] ASTM (2006b). Standard test method for sieve analysis of fine and coarse
aggregates. ASTM C136-06. American Society for Testing and Materials, West
Conshohocken, Pennsylvania.
Internet references link:
1. https://en.wikipedia.org/wiki/Concrete_recycling
2. http://www.slideshare.net/neelanjan06/recycled-aggregate-concrete
3. http://www.google.com.bd
18

APPENDIX
CALCULATION TABLE (A)
Table A-1: Value for the Factor K Harmsworth constants
Table 1. Value for the factor K Harmsworth Constant
Percentage of results allowed to fall
below the minm Value K
0.10 3.09
0.60 2.50
1.00 2.33
2.50 1.96
6.60 1.50
16.00 1.00
From Interpolation 4.5 1.74
Table A-2: Dry Bulk Volume of Coarse Aggregate per Unit Volume of Concrete as
Given by ACI 211.1-91
Table 11.4. Dry Bulk Volume of Coarse Aggregate per Unit Volume of Concrete
as Given by ACI 211.1-91
Maximum size of
Aggregate (mm)
Bulk Volume of dry Rodded coarse aggregate Per unit volume
of concrete for fineness Modulus of Sand of
F.M
- 2.40 2.60 2.80 3.00
10 0.50 0.48 0.46 0.44
12.5 0.59 0.57 0.55 0.53
20 0.66 0.64 0.62 0.60
25 0.71 0.69 0.67 0.65
40 0.75 0.73 0.71 0.69
50 0.78 0.76 0.74 0.72
70 0.82 0.80 0.78 0.76
150 0.87 0.85 0.83 0.81
19

Table A-3: Relation between water/cement ratio and average compressive strength
of concrete, according to ACI 211.1-91
Table 11.5. Relation between water/cement ratio and average compressive
strength of concrete, according to ACI 211.1-91
Average Compressive
strength at 28 day
Effective water/cement ratio (by mass)
(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
Table A-4: Requirements of ACI 318-89 for W/C ratio and Strength for Special
Exposure conditions
Table 11.6. Requirements of ACI 318-89 for W/C ratio and Strength for Special
Exposure conditions
Exposure Condition
Maximum W/C
ratio, normal density
aggregate concrete
Minimum design
strength, low density
aggregate concrete
i. Concrete Intended to be Watertight (MPa)
(a) Exposed to fresh water 0.50 25
(b) Exposed to brackish or sea water 0.45 30
ii. Concrete exposed to freezing and
thawing
(a) Kerbs, Gutters, Guard rails or thin
sections
0.45 30
(b) Other elements 0.50 25
(c) in presence of de-icing chemicals 0.45 30
iii. For corrosion protection of
reinforced concrete exposed to de-
icing salts, brackish water, sea water
or spray from these sources
0.40 33
20

Table A-5: Recommended Values of Slump for Various Type of Construction as
given by ACI 211.1-91
21
Table 11.7. Recommended Values of Slump for Various Type of Construction
as given by ACI 211.1-91
Types of Construction Range of Slump (mm)
Reinforced foundation walls and footings 20-80
Plain footings, Caissons and substructure
walls
20-80
Beams and reinforced walls 20-100
Building columns 20-100
Pavements and slabs 20-80
Mass Concrete 20-80

Table A-6: Approximate requirement for mixing water and air content for
different workability and nominal maximum size of Aggregate according to ACI
211.1-91
Table 11.8. Approximate requirement for mixing water and air content for different
workability and nominal maximum size of Aggregate according to ACI 211.1-91
Workability or
content
water content, Kg/m3
of concrete for indicated maximum aggregate size
(mm)
mm 10 12.5 20 25 40 50 70 150
Slump (mm) Non-air entrained concrete
30-50 205 200 185 180 160 155 145 125
80-100 225 215 200 195 175 170 160 140
150-180 240 230 210 205 185 180 170 -
Approximate
entrapped air
content %
3 2.5 2 1.5 1 0.5 0.3 0.2
Air entrained concrete
30-50 180 175 165 160 145 140 135 120
80-100 200 190 180 175 160 155 150 135
150-180 215 205 190 185 170 165 160 -
Recommended
avg. total air
content %
Mild Exposure
4.50 4.00 3.50 3.00 2.50 2.00 1.50 1.00
Moderate
Exposure
6.00 5.50 5.00 4.50 4.50 4.00 3.50 3.00
Extreme
Exposure
7.50 7.00 6.00 6.00 5.50 5.00 4.50 4.00
22

Table A-7: First Estimate of density (unit weight) of fresh concrete as given by
ACI 211.1-91
Table 11.9. First estimate of density (unit weight) of fresh concrete as given by
ACI 211.1-91
Maximum
size of
Aggregate
(mm)
First Estimate of density (unit weight) of fresh concrete
Non air-entrained (kg/m3) Air-entrained (kg/m3)
10 2285 2190
12.5 2315 2235
20 2355 2280
25 2375 2315
40 2420 2355
50 2445 2375
70 2465 2400
150 2505 2435
Table A-8: Table Required increase in strength (mean strength) for specified
design strength (specified characteristic strength) when no tests records are
available, according to ACI 318-89
Table 11.10. Required increase in strength (mean strength) for specified design
strength (specified characteristic strength) when no tests records are available,
according to ACI 318-89
Specified design strength (MPa) Required increase in Strength (MPa)
less than 21 7.00
21 to 35 8.50
35 or More 10.00
23

CALCULATION TABLE (B)
Table B-1 Determination of Fineness Modulus of Local Sand, Weight of Sample
500 gm
Fineness Modulus of Local Sand
Sieve
No
Opening
(mm)
Retaine
d (gm)
%
Retained
Cum. %
Retained
%
Finer
FM
# 4 4.75 0.0 0.0 0.0 100.0
= 1.33
# 8 2.36 0.0 0.0 0.0 100.0
# 16 1.18 0.0 0.0 0.0 100.0
# 30 0.6 3.0 0.6 0.6 99.4
# 50 0.3 174.0 35.0 35.6 65.0
#100 0.15 301.0 60.6 96.3 39.4
Pan - 18.5 3.7 100.0
Total = 496.5 132.53
Table B-2 Determination of Fineness Modulus of Sylhet sand, Weight of Sample
500gm
Fineness Modulus of Sylhet Sand
Sieve
No
Opening
(mm)
Retain
(gm)
% Retain
Cum. %
Retain
% Finer FM
# 4 4.75 10.0 2.0 2.0 98.0
= 2.34
# 8 2.36 20.0 4.0 6.0 96.0
# 16 1.18 46.0 9.3 15.3 90.7
# 30 0.6 111.0 22.4 37.7 77.6
# 50 0.3 188.0 37.9 75.6 62.1
# 100 0.15 109.0 22.0 97.6 78.0
Pan - 12.0 2.4 100.0
Total= 496.0 234.27
Table B-3 Combined FM (Local & Sylhet Sand)
Fcom
=
Data
Fcom = Combined FM
= M1 = Weight of Sample 1 = 496.5
M2 = Weight of Sample 2 = 496.0
= 1.83 F1 = FM of Sample 1 = 1.33
F2 = FM of Sample 2 = 2.34
24

Table B-4 Determination of Fineness Modulus of Recycled Coarse Aggregate
(RCA)
Fineness Modulus of Recycle Coarse Aggregate
Sieve
(mm)
Opening
(inch)
Retain
(gm)
% Retain
Cum. %
Retain
%
Coarser
FM
63 2.48 0 0 0 100
= 4.20
50 1.97 0 0 0 100
37.5 1.48 0 0 0 100
25 0.98 112 5.61 5.61 94.39
19 0.75 569 28.49 34.10 65.90
16 0.63 403 20.18 54.27 45.73
12.5 0.49 105 5.26 59.53 40.47
9.5 0.37 339 16.97 76.50 23.50
6.3 0.25 315 15.77 92.27 7.73
4.76 0.19 101 5.06 97.33 2.67
Pan - 53.3 2.67 100.00 0
Total= 1997.3 419.62
Table B-5 Determination of Fineness Modulus of Fresh Coarse Aggregate (FCA)
Fineness Modulus of Fresh Coarse Aggregate
Sieve
(mm)
Opening
(inch)
Retain
(gm)
% Retain
Cum. %
Retain
%
Coarser
FM
63 2.48 0 0 0 100
= 5.70
50 1.97 0 0 0 100
37.5 1.48 0 0 0 100
25 0.98 58 2.90 2.90 97.10
20 0.79 1449 72.45 75.35 24.65
14 0.55 396 19.80 95.15 4.85
12.5 0.49 36 1.80 96.95 3.05
10 0.39 49 2.45 99.40 0.60
6.3 0.25 11 0.55 99.95 0.05
4.76 0.19 0 0.00 99.95 0.05
Pan - 1 0.05 100.00 0
Total= 2000.0 569.65
25

CALCULATION TABLE (C)
Table C-1 Unit Weight, Specific Gravity, Absorption Capacity, Moisture Content
of Fine Aggregate (Local Sand)
Unit weight of Local Sand
Specific Gravity, Absorption Capacity, Moisture Content of Local Sand
Local Sand
Specific Gravity =
2.55
Mass of Oven Dry Sample (A) = 481
Mass of Pycnometer + Water (B) = 1322
Mass of S.S.D Sample (S) = 500
Mass of Pycnometer + Water + Sample (C) = 1626
Mass of Air Dry Sample (X)= 494
Absorption Capacity = 3.95
Moisture Content = 2.70
of Fine Aggregate (Sylhet Sand)
26
Height of Mold (h) = 0.181 m
0.180 m
0.180 m
Avg (h) = 0.180 m
Dia of Mold (d) = 0.102 m
0.102 m
0.102 m
Avg (d) = 0.102 m
Wt. of Mold With Agg.= 3.761 kg
Wt. of Mold = 1.395 kg
Wt of Agg. = 2.366 kg
Volume of Aggregate = m3
=0.00147 m3
Unit weight = kg/m3
Unit weight = 1606.00 kg/m3

Unit Weight of Sylhet Sand
Specific Gravity, Absorption Capacity, Moisture Content of Sylhet Sand
Specific Gravity of Sylhet Sand
Specific Gravity =
2.54
Mass of Oven Dry Sample (A) = 485
Mass of Pycno+Water (B) = 1322
Mass of S.S.D Sample (S) = 500
Mass of Pycno + Water + Sample (C) = 1625
Mass of Air Dry Sample (X)= 495
Absorption Capacity = 3.09
Moisture Content = 2.06
27
0.180 m
0.180 m
Avg (h) = 0.180 m
0.102 m
0.102 m
Avg (d) = 0.102 m
Wt. of mold with Agg. 3.605 kg
0.00147
Unit weight = kg/m3

of Recycled Course Aggregate (RCA)
Unit Weight of Recycled Coarse Aggregate
0.242 m
0.241 m
Avg (h) = 0.242 m
0.226 m
0.226 m
Avg (d) = 0.226 m
Wt. of Mold With Agg.= 15.8 kg
= 0.00966 m3
Unit weight = kg/m3
Specific Gravity, Absorption Capacity, Moisture Content of Recycled Course
Aggregate (RCA)
Specific Gravity of Recycle Coarse Aggregate
Specific Gravity =
2.14Wt of sample + Vessel + Water (A) = 2406
Wt of Vessel + Water (B) = 1812
Wt of Saturated Surface Dry Sample (C ) = 1044
Wt of Oven Dry Sample (D) = 961
Apparent Specific Gravity =
Water Absorption Capacity = 8.64
28

of Fresh Course Aggregate (FCA)
Unit Weight of Fresh coarse Aggregate
0.241 m
0.243 m
Avg (h) = 0.242 m
0.224 m
0.223 m
Avg (d) = 0.224 m
Wt. of Mold With Agg. = 19.341 kg
= 0.00950
Unit weight = kg/m3
Unit Weight= = 1628.65 kg/m3
Specific Gravity, Absorption Capacity, Moisture Content of Fresh Course
Aggregate (FCA)
Specific Gravity of Fresh Coarse Aggregate
Specific Gravity =
2.73
Wt of sample + Vessel + Water (A) = 2453
Wt of Saturated Surface Dry Sample (C )
=
1005
Apparent Specific Gravity =
Water Absorption Capacity = 0.70
29

CALCULATION (D)
CONCRETE MIX DESIGN BY (ACI-211.1-91) METHOD
Calculation D-1 Recycle Aggregate Concrete Mix Design for Concrete
Compressive Strength of M 21 (±3000 Psi)
Design Data,
Design Strength, (Fmin) = 21.0 MPa (±3000 Psi)
Standard deviation, (S) = 4.5 {S value is taken from Table-8}
Slump value = 50 mm
(K) = 1.64 {K value is taken from Table-1}
F .m = F min + K S
= 21 + 1.64 x 4.5
= 28.81
=28 MPa
For Mean strength, f m = 28 MPa
W/C = 0.57 {From Table-3}
For Exposure = 0.50 {For Exposure condition from Table-4}
Water content = 185 kg/m3 {From Table-6}
= 370 kg/m3
30

{From Table-2}
Weight of Coarse Aggr. = 0.72 x 1235
Unit weight of Concrete = 2355 kg/m3 {From Table-7}
Weight of F.A = 2355-(185+370+889)
= 911 kg/m3
Step-8: Proportion
= 370: 911: 889: 185
Ratio = 1: 2.46: 2.40: 0.50
= 370: 933: 889: 240
31

Ratio = C: F.A: C.A: W
= 1: 2.52: 2.4: 0.65
32

Design Data,
Slump value = 50 mm
F .m = F min + K S
= 28 + 1.64 x 4.5
= 35.38 MPa
For Mean strength, f m= 35.38 MPa
= 394 kg/m3
{From Table-2}
33

Weight of F.A = 2355-(185+394+889)
= 887 kg/m3
Step-8: Proportion
= 394: 887: 889: 185
Ratio = 1: 2.25: 2.26: 0.47
= 394: 908: 889: 241
= 1: 2.30: 2.26:0.61
34

Design Data,
Slump value = 50 mm
F .m = F min + K S
= 32 + 1.64 x 4.5
= 39.38 MPa
For Mean strength, f m= 39.38 MPa
= 462.5kg/m3
Bulk Volume of C.A = 0.72 m3/m3 of Concrete {From Table-2}
35

Weight of Cement = 462.5 kg/m3
Weight of F.A = 2355-(185+462.5+889)
= 818.5 kg/m3
Step-8: Proportion
= 462.5: 818.5: 889: 185
Ratio = 1: 1.77: 1.92: 0.40
F.A in field application = 818.5 + 19.48 = 838 kg/m3
= 462.5: 838: 889: 242
= 1: 1.81: 1.92: 0.52
36

Calculation D-4 Fresh Aggregate Concrete Mix Design for Concrete Compressive
Strength of M 21 (±3000 Psi)
Sample: Fresh Aggregate Concrete
Design Data,
Slump value = 50 mm
F .m = F min + K S
= 21 + 1.64 x 4.5
= 28.81 MPa
For Mean strength, f m= 28 MPa
= 370 kg/m3
{From Table-2}
37

= 1152 kg/m3 of Concrete
Weight of F.A = 2355-(185+370+1152)
= 648 kg/m3
Step-8: Proportion
= 370: 648: 1152: 185
Ratio = 1: 1.75: 3.11: 0.50
F.A in field application = 648 + 15.42 = 663.4 kg/m3
Water in field application = 185+8.0 -15.42 = 177.58 kg/m3
= 370: 663.4: 1152: 177.58
= 1: 1.79: 3.11: 0.48
38

Design Data,
Slump value = 50 mm
F .m = F min + K S
= 28 + 1.64 x 4.5
= 35.38 MPa
For Mean strength, f m= 32 MPa
= 394 kg/m3
{From Table-2}
39

Weight of F.A = 2355-(185+394+1152)
= 624 kg/m3
Step-8: Proportion
= 394: 624: 1152: 185
Ratio = 1: 1.58: 2.92: 0.47
F.A in field application = 624 + 14.85 = 638.8 kg/m3
= 394: 638.8: 1152: 178.0
= 1: 1.62: 2.92: 0.45
40

Design Data,
Slump value = 50 mm
F .m = F min + K S
= 32 + 1.64 x 4.5
= 32.38 MPa
For Mean strength, f m = 32.38 MPa
= 462.5 kg/m3
{From Table-2}
41

Weight of Cement = 462.5 kg/m3
Weight of F.A = 2355-(185+462.5+1152)
= 555.5 kg/m3
Step-8: Proportion
= 462.5: 555.5: 1152: 185
Ratio = 1: 1.20: 2.50: 0.40
F.A in field application = 555.5 + 13.22 = 568.72 kg/m3
= 462.5: 568.72: 1152: 180.0
= 1: 1.22: 2.50: 0.39
42

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