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 ALAUDDINID: 003-08-04 ID: 003-08-08

Supervised By

Engr. Amrita DasAsst. Professor

DEPARTMENT OF CIVIL ENGINEERINGSOUTHERN 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.

October’ 2016

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 AlauddinID No: 003-08-04 ID No: 003-08-08B.Sc. in Civil Engineering B.Sc. in Civil Engineering Southern University Bangladesh Southern University Bangladesh

ii

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 AlauddinID No: 003-08-04 ID No: 003-08-08B.Sc. in Civil Engineering B.Sc. in Civil Engineering Southern University, Bangladesh Southern University Bangladesh

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SOUTHERN UNIVERSITY BNAGLADESHMEHEDIBAG, 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 DasAsst. ProfessorDepartment of Civil EngineeringSOUTHERN UNIVERSITY, BANGLADESHChittagong.

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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 2016SOUTHERN UNIVERSITY BANGLADESH. AUTHORS

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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.

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TABLE OF CONTENTS

CHAPTER TITLE PAGE

Title Page iLetter of submission iiStudent’s Declaration iiiCertification of Appreciation ivAcknowledgement vAbstract viTable of Contents viiList of Figure ixList of Table xList of Symbols & Abbreviations xi

1. Introduction1.1 Background of the study 11.2 Statement of the problems 21.3 Objective of the study 21.4 Scope of the study 2

2. Literature Review2.1 Introduction 32.2 Summary 32.3 Implication of this research 42.4 How can recycled aggregate use? 42.5 Present knowledge & gap in information 52.6 Why concrete recycling is necessary for Bangladesh? 52.7 Experimental investigation 62.8 Basic properties of recycled aggregate concrete 6

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3. Methodology3.1 Concept 73.2 Experimental Methods 73.3 Research Program 8

4. Result and Discussion4.1 General 94.2 Experimental Data 94.3 Graphical Representation 134.4 Discussion 16

5. Conclusion and Recommendation5.1 Conclusion 175.2 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

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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

4.3.2 Comparison of compressive strength of concrete for Recycle Aggregate Concrete (RAC) and Fresh Aggregate Concrete (FAC) between Curing Periods M 28

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4.3.3 Comparison of compressive strength of concrete for Recycle Aggregate Concrete (RAC) and Fresh Aggregate Concrete (FAC) 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

4.3.5 Comparison of compressive strength Gain % of concrete for Recycle Aggregate Concrete (RAC) vs Fresh Aggregate Concrete (FAC)M 28 15

4.3.6 Comparison of compressive strength Gain % of concrete for Recycle Aggregate Concrete (RAC) vs Fresh Aggregate Concrete (FAC)M 32 15

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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



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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

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CHAPTER 1INTRODUCTION

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.

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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.

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CHAPTER 2LITERATURE 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

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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 aggregate1) 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

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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. Building waste that may generate from natural calamities like Earthquake.

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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

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CHAPTER 3METHODOLOGY

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.

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3.3 Research Program

Figure 1.1 Research program of this thesis

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MATERIALS COLLECTION

FRESH AGGREGATE DEMOLISHED AGGREGATE

FINE AGGREGATE CEMENT

TEST OF THE MATERIALS PROPERTIES

MIX 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 1.33Sylhet Sand 2.34

Combined (Local & Sylhet) 1.83

Coarse Aggregate F.MRecycled 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

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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 ConcreteDesign Data,Design Strength, (Fmin) = 21 MPaStandard deviation, (S) = 4.5 {S value is taken from Table-8, P-24}Specific Gravity of (F.A) = 2.54Specific Gravity of (C.A) = 2.14Unit wt. of (C.A) = 1235 kg/m3

Fineness Modulus of (F.M) = 1.83Maximum Size of C.A = 20 mmSlump value = 50 mmAbsorption 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 StrengthF .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 MPaW/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

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= 370 kg/m3Step-4: Volume of Coarse Aggregate

F.M of fine Aggregate = 1.83Bulk 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/m3Weight of Cement = 370 kg/m3Weight of C.A = 889 kg/m3Weight of F.A = 2355-(185+370+889)

= 911 kg/m3Step-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

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Table 4.2.5 Concrete mix design ratio by (ACI-211.1-91)

Using Recycled AggregateUsing Recycled AggregateStrengthStrength CementCement Sand Sand StoneStone W/CW/C

M 21M 21 (±3000 psi) (±3000 psi) 11 2.532.53 2.392.39 0.650.65M 28M 28 (±4000 psi) (±4000 psi) 11 2.332.33 2.262.26 0.610.61M 32M 32 (±4600 psi) (±4600 psi) 11 1.831.83 1.921.92 0.530.53

Using Fresh AggregateUsing Fresh AggregateStrengthStrength CementCement SandSand StoneStone W/CW/C

M 21M 21 (±3000 psi) (±3000 psi) 11 1.811.81 3.103.10 0.480.48M 28M 28 (±4000 psi) (±4000 psi) 11 1.651.65 2.932.93 0.450.45M 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 1726.4121 15.64 20.72 2267.64 3004.0228 16.31 20.90 2364.92 3030.9060 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 2322.6821 17.78 23.04 2577.72 3340.5128 17.95 27.69 2602.95 4014.7460 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 2388.4121 21.08 31.63 3056.93 4586.0828 22.41 31.90 3249.92 4625.4160 22.89 32.13 3319.63 4658.74

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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 (RAC) vs. Fresh Aggregate Concrete (FAC) between Curing Periods M 21


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

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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.

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CHAPTER 5CONCLUSION 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

http://www.google.com.bd/

http://www.slideshare.net/neelanjan06/recycled-aggregate-concrete

https://en.wikipedia.org/wiki/Concrete_recycling

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 3.090.60 2.501.00 2.332.50 1.966.60 1.5016.00 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 0.4412.5 0.59 0.57 0.55 0.5320 0.66 0.64 0.62 0.6025 0.71 0.69 0.67 0.6540 0.75 0.73 0.71 0.6950 0.78 0.76 0.74 0.7270 0.82 0.80 0.78 0.76150 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 concrete45 0.38 -40 0.43 -35 0.48 0.4030 0.55 0.4625 0.62 0.5320 0.70 0.6115 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 ConditionMaximum 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 30ii. 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 30iii. 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

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 20-80Plain footings, Caissons and substructure walls 20-80

Beams and reinforced walls 20-100Building columns 20-100Pavements and slabs 20-80Mass Concrete 20-80

21

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 150Slump (mm) Non-air entrained concrete

30-50 205 200 185 180 160 155 145 12580-100 225 215 200 195 175 170 160 140150-180 240 230 210 205 185 180 170 -

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 12080-100 200 190 180 175 160 155 150 135150-180 215 205 190 185 170 165 160 -

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 219012.5 2315 223520 2355 228025 2375 231540 2420 235550 2445 237570 2465 2400150 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 7.0021 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 SandSieve No

Opening (mm)

Retained (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 39.4Pan - 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 SandSieve 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 78.0Pan - 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 AggregateSieve (mm)

Opening (inch)


Retain%

Coarser FM

63 2.48 0 0 0 100

= 4.20

50 1.97 0 0 0 10037.5 1.48 0 0 0 10025 0.98 112 5.61 5.61 94.3919 0.75 569 28.49 34.10 65.9016 0.63 403 20.18 54.27 45.73

12.5 0.49 105 5.26 59.53 40.479.5 0.37 339 16.97 76.50 23.506.3 0.25 315 15.77 92.27 7.734.76 0.19 101 5.06 97.33 2.67Pan - 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 AggregateSieve (mm)

Opening (inch)


Retain%

Coarser FM

63 2.48 0 0 0 100

= 5.70

50 1.97 0 0 0 10037.5 1.48 0 0 0 10025 0.98 58 2.90 2.90 97.1020 0.79 1449 72.45 75.35 24.6514 0.55 396 19.80 95.15 4.85

12.5 0.49 36 1.80 96.95 3.0510 0.39 49 2.45 99.40 0.606.3 0.25 11 0.55 99.95 0.054.76 0.19 0 0.00 99.95 0.05Pan - 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 =

2.55Mass of Oven Dry Sample (A) = 481

Mass of Pycnometer + Water (B) = 1322Mass of S.S.D Sample (S) = 500

Mass of Pycnometer + Water + Sample (C) = 1626Mass of Air Dry Sample (X)= 494

Absorption Capacity = 3.95

Moisture Content = 2.70

26

Height of Mold (h) = 0.181 m 0.180 m 0.180 m

Avg (h) = 0.180 mDia of Mold (d) = 0.102 m

0.102 m0.102 m

Avg (d) = 0.102 mWt. of Mold With Agg.= 3.761 kg

Wt. of Mold = 1.395 kgWt of Agg. = 2.366 kg

Volume of Aggregate = m3

=0.00147 m3Unit weight = kg/m3

Unit weight = 1606.00 kg/m3

Table C-2 Unit Weight, Specific Gravity, Absorption Capacity, Moisture Content of Fine Aggregate (Sylhet Sand)

Unit Weight of Sylhet Sand

Specific Gravity, Absorption Capacity, Moisture Content of Sylhet Sand

Specific Gravity of Sylhet Sand

Specific Gravity =

2.54Mass of Oven Dry Sample (A) = 485

Mass of Pycno+Water (B) = 1322Mass of S.S.D Sample (S) = 500

Mass of Pycno + Water + Sample (C) = 1625Mass of Air Dry Sample (X)= 495

Absorption Capacity = 3.09

Moisture Content = 2.06

27



0.102 m 0.102 m

Avg (d) = 0.102 mWt. of mold with Agg. 3.605 kg



0.00147 Unit weight = kg/m3


Table C-3 Unit Weight, Specific Gravity, Absorption Capacity, Moisture Content of Recycled Course Aggregate (RCA)

Unit Weight of Recycled Coarse Aggregate



0.226 m0.226 m

Avg (d) = 0.226 mWt. 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) = 2406Wt of Vessel + Water (B) = 1812

Wt of Saturated Surface Dry Sample (C ) = 1044Wt of Oven Dry Sample (D) = 961

Apparent Specific Gravity =


Wt of Oven Dry Sample (D) = 961

Water Absorption Capacity = 8.64

28

Table C-4 Unit Weight, Specific Gravity, Absorption Capacity, Moisture Content of Fresh Course Aggregate (FCA)

Unit Weight of Fresh coarse Aggregate

Height of Mold (h) = 0.242 m 0.241 m

0.243 mAvg (h) = 0.242 m

Dia of Mold (d) = 0.224 m 0.224 m

0.223 mAvg (d) = 0.224 m

Wt. of Mold With Agg. = 19.341 kgWt. of Mold = 3.863 kgWt of Agg. = 15.478 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 =

2.73Wt of sample + Vessel + Water (A) = 2453

Wt of Vessel + Water (B) = 1814Wt 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)

Sample: Recycled Aggregate Concrete

Design Data,Design Strength, (Fmin) = 21.0 MPa (±3000 Psi)Standard deviation, (S) = 4.5 {S value is taken from Table-8}Specific Gravity of (F.A) = 2.54Specific Gravity of (C.A) = 2.14Unit wt. of (C.A) = 1235 kg/m3

Fineness Modulus of (F.M) = 1.83Maximum Size of C.A = 20 mmSlump value = 50 mmAbsorption Capacity of C.A = 8.64 %Free surface Moisture in (F.A) = 2.38 %(K) = 1.64 {K value is taken from Table-1}

Step-1: Mean Strength

F .m = F min + K S= 21 + 1.64 x 4.5= 28.81=28 MPa


For Mean strength, f m = 28 MPaW/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

Step-4: Volume of Coarse Aggregate


{From Table-2}


Weight of Coarse Aggr. = 0.72 x 1235= 889.2 kg/m3 of Concrete


Unit weight of Concrete = 2355 kg/m3 {From Table-7}



= 911 kg/m3Step-8: Proportion


Ratio = 1: 2.46: 2.40: 0.50Step-9: Proportion required for field application






Materials = Cement: F.A: C.A: Water

= 370: 933: 889: 240

31

Ratio = C: F.A: C.A: W

= 1: 2.52: 2.4: 0.65

32





Step-1: Mean Strength

F .m = F min + K S= 28 + 1.64 x 4.5= 35.38 MPa


For Mean strength, f m= 35.38 MPaW/C = 0.47 {From Table-3}





= 394 kg/m3



{From Table-2}

33


Weight of coarse Aggr. = 0.72 x 1235= 889.2 kg/m3 of Concrete





= 887 kg/m3

Step-8: Proportion


Ratio = 1: 2.25: 2.26: 0.47








Ratio = C: F.A: C.A: W= 1: 2.30: 2.26:0.61

34






= 32 + 1.64 x 4.5= 39.38 MPa


For Mean strength, f m= 39.38 MPaW/C = 0.40 {From Table-3}





= 462.5kg/m3


F.M of fine Aggregate = 1.83Bulk Volume of C.A = 0.72 m3/m3 of Concrete {From Table-2}


Weight of coarse Aggr. = 0.72 x 1235

35

= 889.2 kg/m3 of ConcreteStep-6: Unit weight of Concrete



Weight of Water = 185 kg/m3Weight of Cement = 462.5 kg/m3Weight of C.A = 889 kg/m3Weight of F.A = 2355-(185+462.5+889)

= 818.5 kg/m3

Step-8: Proportion

Materials = Cement: F.A: C.A: Water= 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




Materials = Cement: F.A: C.A: Water= 462.5: 838: 889: 242

Ratio = C: F.A: C.A: W= 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




= 21 + 1.64 x 4.5= 28.81 MPa


For Mean strength, f m= 28 MPaW/C = 0.57 {From Table-3}





= 370 kg/m3



{From Table-2}



37

= 1152 kg/m3 of ConcreteStep-6: Unit weight of Concrete




= 648 kg/m3

Step-8: Proportion


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


Materials = Cement: F.A: C.A: Water= 370: 663.4: 1152: 177.58

Ratio = C: F.A: C.A: W= 1: 1.79: 3.11: 0.48

38






= 28 + 1.64 x 4.5= 35.38 MPa


For Mean strength, f m= 32 MPaW/C = 0.47 {From Table-3}





= 394 kg/m3



{From Table-2}



39





= 624 kg/m3

Step-8: Proportion


Ratio = 1: 1.58: 2.92: 0.47



F.A in field application = 624 + 14.85 = 638.8 kg/m3




Materials = Cement: F.A: C.A: Water= 394: 638.8: 1152: 178.0

Ratio = C: F.A: C.A: W= 1: 1.62: 2.92: 0.45

40






= 32 + 1.64 x 4.5= 32.38 MPa


For Mean strength, f m = 32.38 MPaW/C = 0.40 {From Table-3}





= 462.5 kg/m3



{From Table-2}



41




Weight of Water = 185 kg/m3Weight of Cement = 462.5 kg/m3Weight of C.A = 1152 kg/m3Weight of F.A = 2355-(185+462.5+1152)

= 555.5 kg/m3

Step-8: Proportion

Materials = Cement: F.A: C.A: Water= 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




Materials = Cement: F.A: C.A: Water= 462.5: 568.72: 1152: 180.0

Ratio = C: F.A: C.A: W= 1: 1.22: 2.50: 0.39

42

an investigation on processing and properties of recycle aggregate concrete

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