concrete flatwork that will have a smooth troweled finish. In high cement content ... popular as they improve the finishability of concrete flatwork. Mid-range water.
THE PROPERTIES AND FLEXURAL BEHAVIOUR OF SELF COMPACTING CONCRETE USING RICE HUSK ASH AND ADMIXTURE
MOHD FAKRI BIN MUDA
A project report submitted in partial fulfilment of the Requirements for the award of the degree of Master of Engineering (Civil – Structure)
Faculty of Civil Engineering Universiti Teknologi Malaysia
NOVEMBER 2009
iii
Especially to…
My beloved FATHER and MOTHER ; MUDA BIN AWANG and ROHANI BINTI ABD KADIR Thank you for your softness in take care of me, supporting, advisory and loving that gives my life happiness all the time.
My love BROTHER and SISTER ; FAIZAL, FAUZI, FAHMI, NOR ILYANI dan FAIZ Your support always motivated me and helping when I need it most.
To All My Friends ; Thanks for all the supports.
Wish all the happiness and cheerfulness will always colouring our life.
iv
ACKNOWLEDGEMENT
First and foremost, gratitude and praises goes to ALLAH S.A.W, in whom I have put my faith and trust in. During the entire course of this study, my faith has been tested countless times and with the help of the Almighty, I have been able to pass the obstacles that stood in my way. I also would like to take this opportunity to express profound gratitude to my research supervisor Assoc. Prof. Dr. A. Aziz Saim for the noble guidance and valuable advice throughout the period of study. His patience, time, and understanding are highly appreciated. A word of thanks also goes to the staffs of Material Laboratory of Faculty of Civil Engineering who were directly or indirectly involved in the process of producing this research report, for their generous assistance, useful views and tips. My sincere appreciation also extends to all my colleagues especially Sa, Nasir, Khairi, Apai and Sheikh and others who have provided assistance at various. Their views and tips are useful indeed. Unfortunately, it is not possible to list all of them in this limited space. Last but not the least I would like to thank my family members whom I owe a debt of attitude for their prayers, encouragement and moral support throughout the whole duration of studies.
v
ABSTRACT
Technology in concrete has been developing in many ways to enhance the quality and properties of concrete. One of the technological advances in improving the quality of concrete is by using self compacting concrete (SCC). This research was carried out to establish the properties and flexural behaviour of SCC using rice husk ash (RHA) and admixture with mix design of constant water-cement ratio. The main objective of this study is to find the suitable concrete composition which can be categorized as SCC that using RHA as cement replacement material together with admixture. There are nine composition of mixes were prepared and laboratory test was carried out to investigate the properties of fresh SCC and the strength development of hardened SCC. A total of 108 concrete cube specimens 100 mm x 100 mm x 100 mm were prepared for compression test at 1, 7, 14 and 28 days. Three 100 mm x 200 mm x 1500 mm reinforced concrete beams were prepared for flexural test. Two beams were casted using the optimum mix of SCC while the other one made of normal concrete (NC) to act as control. The results for cubes tests indicated that sample with 5% RHA and 1% Sika Viscocrete is the optimum composition for SCC. This composition increased the performance of hardened concrete. While for the flexural test, SCC concrete have better performance than NC and result for adding RHA as a cement replacement material does not give any significant differences in flexural strength of SCC.
vi
ABSTRAK
Teknologi konkrit telah berkembang dalam pelbagai skop bagi meningkatkan kualiti dan sifat-sifat konkrit. Salah satu teknologi maju yang digunakan untuk meningkatkan kualiti konkrit ialah Konkrit Tanpa Mampatan (SCC). Kajian ini dijalankan untuk mengkaji sifat-sifat dan kelakuan lenturan konkrit tanpa mampatan yang menggunakan abu sekam padi (RHA) dan bahan tambah dengan nisbah airsimen dimalarkan. Objektif utama kajian ini adalah untuk mencari nisbah komposisi konkrit yang sesuai yang boleh dikategorikan sebagai konkrit tanpa mampatan dengan menggunakan abu sekam padi sebagai bahan pengganti simen bersama dengan bahan tambah. Sebanyak sembilan komposisi konkrit disediakan dan ujian makmal dijalankan bagi mengkaji sifat-sifat konkrit basah dan juga keras. Sejumlah 108 kuib bersaiz 100 mm x 100 mm disediakan untuk ujian kekuatan mampatan pada konkrit berumur 1, 7, 14 dan 28 hari. Tiga rasuk bertetulang bersaiz 100 mm x 200 mm x 1500 mm disediakan untuk ujian kekuatan lenturan. Dua rasuk dibancuh dengan menggunakan bancuhan optimum konkrit tanpa mampatan dan satu lagi menggunakan bancuhan konkrit biasa bertindak sebagai rujukan. Ujian kiub menunjukkan sampel dengan campuran 5% abu sekam padi dan 1% Sika Viscocrete adalah komposisi optimum untuk konkrit tanpa mampatan. Komposisi ini meningkatkan kekuatan konkrit keras. Untuk ujian kekuatan lenturan, konkrit tanpa mampatan mempunyai kekuatan lenturan yang lebih baik berbanding konkrit biasa dan kesan penggunaan abu sekam padi sebagai bahan pengganti simen tidak memberikan kesan yang besar pada kekuatan lenturan konkrit tanpa mampatan.
vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF ABBREVIATIONS
xiv
LIST OF SYMBOLS
xvi
LIST OF APPENDICES
xvii
INTRODUCTION
1
1.1
Background
1
1.2
Problem Statement
2
1.3
Objectives
3
1.4
Research Scope
3
1.5
Research Significance
4
LITERATURE REVIEW
5
2.1
Introduction
5
2.2
Self Compacting Concrete
6
viii 2.3
Development of SCC
8
2.4
Application of CSS in Worldwide
9
2.5
Advantages and Benefits of SCC
10
2.6
Cement Replacement Material
11
2.4.1
Pozzolanic Material
12
2.4.2
Types of Cement Replacement Material
12
2.7
Rice Husk Ash
16
2.8
Admixtures
19
2.8.1
Air-Entraining Admixtures
20
2.8.2
Water Reducing Admixtures
21
2.8.3
Accelerating Admixtures
21
2.8.4
Retarders Admixtures
22
2.8.5
Superplasticizers Admixtures
23
2.9
3
Previous Research on SCC
24
METHODOLOGY
26
3.1
Introduction
26
3.2
Experimental Program
27
3.3
Instrumentation and Laboratory Works
28
3.3.1 Raw Material
28
3.4
3.3.1.1 Cement
28
3.3.1.2 Fine Aggregate
29
3.3.1.3 Course Aggregate
30
3.3.1.4 Water
30
3.3.1.5 Rice Husk Ash
30
3.3.1.6 Admixture
31
Specimen Preparation
32
3.4.1
Concrete Mixes
32
3.4.2
Specimens
33
3.4.3 Mixing Process
34
3.4.4 Placing Process
35
3.4.5 Curing Process
37
ix
3.5
Test Instrumentations and Procedures
38
3.5.1
38
Test on Fresh Concrete 3.5.1.1 Slump Flow Test and Slump Flow T50 Test
4
5
38
3.5.1.2 Slump Test
40
3.5.1.3 L-Box Test
42
3.5.1.4 Sieve Stability Test
44
3.5.2 Test on Hardened Concrete
45
3.5.2.1 Compression Test
45
3.5.2.2 Flexural Test
46
RESULTS AND DISCUSSIONS
49
4.1
Introduction
49
4.2
The Properties of Fresh Concrete
50
4.3
The Strength Development of Hardened Concrete
54
4.4
The Flexural Behaviour
58
4.5
Crack Patterns
61
4.6
Summary
62
CONCLUSIONS AND RECOMMENDATIONS
63
5.1
Conclusions
63
5.2
Recommendations
65
REFERENCES
APPENDIX A – M
66
69 - 84
x
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Physical and chemical properties of RHA
18
3.1
Properties of cement
29
3.2(a)
Concrete mix composition
34
3.2(b)
Detail of beam mix composition
34
4.1
Results of fresh concrete test
50
4.2
Average compressive strength result
55
4.3
Flexural test result
58
5.1
Sample 5R1.0 composition
64
xi
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
2.1
Self compacted concrete
7
2.2
Necessity of SCC
8
2.3
Fly ash
13
2.4
Kaolin
14
2.5
Silica fume
15
2.6
Rice husk ash
17
2.7
X-ray diffractograms of RHA sample
18
2.8
Particle size distribution of RHA after 4 hours of grounding
19
3.1
Flow chart of the research laboratory work
27
3.2
Mix designation
33
3.3
Concrete mixer machine
35
3.4
Placing process
36
xii
3.4
Placing process
36
3.5
Beams and cubes after placing process
36
3.6
Water tank curing
37
3.7
Gunnysacks curing for beams
37
3.8
Slump flow test and slump flow T50 test equipment
39
3.9
Slump flow test
39
3.10
Slump test
41
3.11
L-Box test equipment
42
3.12
The L-Box test dimension
43
3.13
Compressive strength machine
46
3.14
Detail of beam and flexural test setup
47
3.15
Flexural test
48
4.1
Slump flow test result
51
4.2
T50 test result
52
4.3
L-Box test result
53
4.4
Sieve stability test result
53
4.5
Average compressive strength result
56
xiii
4.6(a)
Poor self compaction
57
4.6(b)
Good self compaction
57
4.7
Flexural result for all beam- Load(kN) versus deflection(mm)
60
4.8(a)
Crack pattern for BCC0.5
61
4.8(b)
Crack pattern for BCC1.0
61
4.8(c)
Crack pattern for 5BR1.0
62
xiv
LIST OF ABBREVIATIONS
SCC
-
Self compacted concrete
NC
-
Normal concrete
RHA
-
Rice husk ash
OPC
-
Ordinary Portland cement
PC
-
Portland cement
w/b
-
Water-binder ratio
CO 2
-
Carbon dioxide
SiO 2
-
Silica Oxide
H2O
-
Water
Al 2 O 3
-
Aluminums Oxide
CRM
-
cement replacement material
GGBS
-
Ground granulated blast furnace slag
ASTM
-
American Standard Test Method
xv
HRWR
-
High range water reducer
POFA
-
Palm oil fuel ash
FA
-
Fly ash
NVC
-
Normally vibrate concrete
MS
-
Malaysian standard
CC
-
Normal concrete
R
-
Concrete with rice husk ash
BS
-
British standard
xvi
LIST OF SYMBOLS
E
-
Modules of elasticity
Fcu
-
Compressive strength
H1
-
Length at start point of L-Box test
H2
-
Length at end point of L-Box test
xvii
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A
Test results for sample CC0.5
69
B
Test results for sample CC1.0
70
C
Test results for sample 5R1.0
71
D
Test results for sample 7.5R1.0
72
E
Test results for sample 10R1.0
73
F
Test results for sample CC1.5
74
G
Test results for sample 5R1.5
75
H
Test results for sample 7.5R1.5
76
I
Test results for sample 10R1.5
77
J
Compression test results for beam’s cube
78
K
Flexural test result for BCC0.5
79
L
Flexural test result for BCC1.0
81
M
Flexural test result for 5BR1.0
83
CHAPTER 1
INTRODUCTION
1.1
Background
The importance of concrete in modern society cannot be underestimated. There is no escaping from the impact of concrete on everyday life. Concrete is a composite material which is made of filler and a binder. Typical concrete is a mixture of fine aggregate (sand), coarse aggregate (rock), cement, and water. Nowadays the usage of concrete is increasing from time to time due to the rapid development of construction industry. The usage of concrete is not only in building construction but also in other areas such as road construction, bridges, harbor and many more. Thus technology in concrete has been developing in many ways to enhance the quality and properties of concrete. One of the technological advances in improving the quality of concrete is Self Compacting Concrete.
Self-compacting concrete (SCC) is considered as a concrete which can be placed and compacted under its self-weight with little or no vibration effort, and which is at the same time cohesive enough to be handled without segregation or bleeding. The use of chemical admixtures is always necessary when producing SCC in order to increase the workability and reduce segregation. The content of coarse aggregate and the water to binder ratio in SCC are lower than those of normal
2 concrete. Therefore SCC contains large amounts of fine particles such as palm oil fuel ash (POFA), blast-furnace slag, fly ash and rice husk ash (RHA) in order to avoid gravity segregation of larger particles in the fresh mix.
This research was implemented to develop and to determine the properties and flexural behaviour of Self Compacting Concrete (SCC) by using Rice Husk Ash (RHA) and admixture.
1.2
Problem Statement
The explosive expansion of plantation in Malaysia has generated enormous amounts of vegetable waste, creating problems in replanting operations and tremendous environmental concerns. When left on the plantation floor, these materials create great environmental problems [18]. For this reason, economic utilization of this waste will be beneficial. Some countries are experiencing predicament in disposal of rice husk heaps due to their abundance. Concrete technologists are gradually finding applications in rice husk ash (RHA) as an additive for producing high-strength concrete. The use of rice husk ash, an indigenous agro-waste in its raw form, as a supplementary binder to cement for treatment of contaminated soils not only can create new workable and high strength concrete also assists in alleviating disposal problem of rice husk heaps in Asian countries.
3 1.3
Objectives
The objective of this study are :
1) To produce a suitable concrete composition which can be categorized as SCC that using RHA as cement replacement material together with admixture. 2) To investigate the properties and strength development of SCC. 3) To compare the flexural behavior of reinforced concrete beam of SCC and normal concrete (NC).
1.4
Research Scope
The scope of this research are :
1) The mixtures of SCC are only using rice husk ash (RHA) as cement replacement material and admixtures (Sika ViscoCrete-15RM) 2) Ordinary Portland Cement (OPC) is used for the proposed SCC mix. 3) The water- binder ratio (w/b) for all the mixes is fixed at 0.38. 4) The comparison in flexural behaviour aspect only involves the most optimum design mix of SCC to be compared with normal concrete.
4 1.5
Research Significance
Concrete has been used in the construction industry for centuries. Many modifications and developments have been made to improve the performance of concrete, especially in terms of strength and workability. Engineers has found new technology of concrete called Self Compacted Concrete that use pozzolans as a cement replacement material together with admixtures.
The introduction of pozzolans as cement replacement materials in recent years seems to be successful. The use of pozzolan has proven to be an effective solution in enhancing the properties of concrete in terms of strength and workability. The current pozzolans in use are fly ash, silica fume and slag. Development and investigation of other sources of pozzolan such as rice husk ash will be able to provide alternatives for the engineer to select the most suitable cement replacement material for more cheaper material.
Like other pozzolans, rice husk ash is a by-product which can be abundantly found in this country. Therefore, using rice husk ash should promise some advantages in reduce the environmental problems. In this case, studies are needed to determine the properties and behaviour of SCC using rice husk ash.
In addition, the use of rice husk ash as a cement replacement material is not common in the Malaysian construction sector. This study will be able to enhance the understanding on the suitability of rice husk ash as cement replacement material.
CHAPTER 2
LITERATURE REVIEW
2.1
Introduction
There has been an increase in using self-compacting concrete (SCC) in recent years and numerous of papers have been published. SCC was first developed in Japan in the late nineteen eighties to be used in the construction of skyscrapers. The introduction of SCC represents major technological advances, which leads to a better quality concrete and an efficient construction process. SCC allows the construction of more slender building elements and more complicated and interesting shapes. The production of SCC allows the pumping of concrete to a great height and the flow through congested reinforcing bars without the use of compaction other than the concrete self-weight. As a result, the use of SCC can lead to a reduction in construction time, labour cost and noise level on the construction site.
6 2.2
Self Compacting Concrete
Self compacting concrete (SCC), is a new kind of high performance concrete (HPC) with excellent deformability and segregation resistance. It is a flowing concrete without segregation and bleeding, capable of filling spaces in dense reinforcement or inaccessible voids without hindrance or blockage. The composition of SCC must be designed in order not to separate and not to excessively bleed. Concrete strength development is determined not only by the water-to-cement ratio, but also is influenced by the content of other concrete ingredients like cement replacement material and admixtures.
Two important properties specific to SCC in its plastic state are its flowability and stability. The high flowability of SCC is generally attained by using highrangewater-reducing (HRWR) admixtures and not by adding extra mixing water. The stability or resistance to segregation of the plastic concrete mixture is attained by increasing the total quantity of fines in the concrete and/or by using admixtures that modify the viscosity of the mixture[1]. Increased fines contents can be achieved by increasing the content of cementititious materials or by incorporating mineral fines. Admixtures that affect the viscosity of the mixture are especially helpful when grading of available aggregate sources cannot be optimized for cohesive mixtures or with large source variations. A well distributed aggregate grading helps achieve SCC at reduced cementitious materials content and/or reduced admixture dosage. While SCC mixtures have been successfully produced with 1½ inch (38 mm) aggregate, it is easier to design and control with smaller size aggregate. Control of aggregate moisture content is also critical to producing a good mixture. SCC mixtures typically have a higher paste volume, less coarse aggregate and higher sand-coarse aggregate ratio than typical concrete mixtures.
Retention of flowability of SCC at the point of discharge at the jobsite is an important issue. Hot weather, long haul distances and delays on the jobsite can result in the reduction of flowability whereby the benefits of using SCC are reduced. Job site water addition to SCC may not always yield the expected increase in flowability and could cause stability problems. Full capacity mixer truck loads may not be
7 feasible with SCCs of very high flowability due to potential spillage. In such situations it is prudent to transport SCC at a lower flowability and adjust the mixture with HRWR admixtures at the job site. Care should be taken to maintain the stability of the mixture and minimize blocking during pumping and placement of SCC through restricted spaces. Formwork may have to be designed to withstand fluid concrete pressure and conservatively should be designed for full head pressure. Once the concrete is in place it should not display segregation or bleeding/settlement.
SCC mixtures as shown in Figure 2.1 can be designed to provide the required hardened concrete properties for an application, similar to regular concrete. If the SCC mixture is designed to have a higher paste content or fines compared to conventional concrete, an increase in shrinkage may occur.
Figure 2.1 : Self compacted concrete
8 2.3
Development of SCC
For several years beginning in 1983, the problem of the durability of concrete structures was a major topic of interest in worldwide. To make durable concrete structures, sufficient compaction by skilled workers is required. However, the gradual reduction in the number of skilled workers in construction industry has led to a similar reduction in the quality of construction work. One solution for the achievement of durable concrete structures independent of the quality of construction work is the employment of self-compacting concrete, which can be compacted into every corner of a formwork, purely by means of its own weight and without the need for vibrating compaction (Figure 2.2). The necessity of this type of concrete was proposed by Okamura in 1986. Studies to develop self-compacting concrete, including a fundamental study on the workability of concrete, were carried out by Ozawa and Maekawa at the University of Tokyo[19].
Figure 2.2 : Necessity of SCC
The prototype of self-compacting concrete was first completed in 1988 using materials already on the market. The prototype performed satisfactorily with regard to drying and hardening shrinkage, heat of hydration, denseness after hardening, and
9 other properties. This concrete was named “High Performance Concrete.” and was defined as follows at the three stages of concrete. At almost the same time, “High Performance Concrete” was defined as a concrete with high durability due to low water-cement ratio by Professor Aitcin. Since then, the term high performance concrete has been used around the world to refer to high durability concrete. Therefore, Okamura has changed the term for the proposed concrete to “SelfCompacting High Performance Concrete”[19].
2.4
Application of SCC in Worldwide
Since the development of the prototype of self-compacting concrete in 1988, the use of self-compacting concrete in actual structures has gradually increased. A typical application example of Self-compacting concrete is the two anchorages of Akashi-Kaikyo (Straits) Bridge opened in April 1998, a suspension bridge with the longest span in the world (1,991 meters). The volume of the cast concrete in the two ahchorages amounted to 290,000 m3. A new construction system, which makes full use of the performance of self-compacting concrete, was introduced for this. The concrete was mixed at the batcher plant beside the site, and was the pumped out of the plant. It was transported 200 meters through pipes to the casting site, where the pipes were arranged in rows 3 to 5 meters apart. The concrete was cast from gate valves located at 5 meter intervals along the pipes. These valves were automatically controlled so that a surface level of the cast concrete could be maintained. In the final analysis, the use of self-compacting concrete shortened the anchorage construction period by 20%, from 2.5 to 2 years [19].
Self-compacting concrete was used for the wall of a large LNG tank belonging to the Osaka Gas Company, whose concrete casting was completed in June 1998. The volume of the self-compacting concrete used in the tank amounted to 12,000 m2. The adoption of self-compacting concrete means that the number of lots decreases from 14 to 10, as the height of one lot of concrete casting was increased and the number of
10 concrete workers was reduced from 150 to 50. The construction period of the structure also has decreased from 22 months to18 months [19].
2.5
Advantages and Benefits of SCC
SCC offers many advantages and benefits for the precast, prestressed industry and for the cast-in-place construction as follows:
1. Can be placed at a faster rate with no mechanical vibration and less screeding, resulting in savings in placement costs. 2. Improved and more uniform architectural surface finish with little to no remedial surface work. 3. Ease of filling restricted sections and hard-to-reach areas. Opportunities to create structural and architectural shapes and surface finishes not achievable with conventional concrete. 4. Improved consolidation around reinforcement and bond with reinforcement 5. Improved pumpability. 6. Improved uniformity of in-place concrete by eliminating variable operatorrelated effort of consolidation. 7. Labour savings. 8. Shorter construction periods and resulting cost savings. 9. Quicker concrete truck turn-around times enabling the producer to service the project more efficiently. 10. Reduction or elimination of vibrator noise potentially increasing construction hours in urban areas. 11. Minimizes movement of ready mixed trucks and pumps during placement. 12. Increased jobsite safety by eliminating the need for consolidation.
11 2.6
Cement Replacement Materials
With the extensively use of cement in concrete, there has been some environmental concerns in terms of damage caused by the extraction of raw material and CO2 emission during cement manufacture. This has brought pressures to reduce the cement consumption in the industry. At the same time, there are getting more requirements for enhancement in concrete durability to sustain the changing environment which is apparently different from the old days.
With the development in concrete technology, cement replacement materials (CRM) have been introduced as substitutes for cement in concrete. Several types of materials are in common use, some of which are by-products from other industrial processes, and hence their use may have economic advantages. However, the main reason for their use is that they can give a variety of useful enhancements or modifications to the concrete properties. All the materials have two common features :
1) Their particle size range is similar to or smaller than that of Portland cement. 2) They are pozzolan material.
2.6.1
Pozzolanic Material
A common feature of nearly all CRM is that they exhibit pozzolanic behaviour. Pozzolanic materials the materials which contains active silica (SiO2) and is not cementitious in itself but will, in a finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form cementitious compounds [20].
12 2.6.2
Types of Cement Replacement Material
The main cement replacement materials in use world-wide are:
i.
Fly Ash
Fly ash (shown in Figure 2.3) is the finely divided mineral residue resulting from the combustion of powdered coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Coal can range in ash content from 2%-30%, and of this around 85% becomes fly ash. It can replace up to 50% by mass of Portland cement [22], which can add to the final strength of the concrete and increase chemical resistance and durability.
Figure 2.3 : Fly ash
13 ii.
Ground Granulated Blast Furnace Slag (GGBS)
Ground granulated blast furnace slag or slag is the by-product of smelting ore to purify metals. They can be considered to be a mixture of metal oxides. However, they can contain metal sulphides and metal atoms in the elemental form [22]. Slags are generally used as a waste removal mechanism in metal smelting but they can also serve other purposes such as assisting in smelt temperature control and to minimize re-oxidation of the final product before casting.
Slag has a pozzolanic reaction which allows the increase of concrete strength. Slag has proven to produce very good and dense concrete allowing increased durability.
iii.
Kaolin
The name kaolin is derived from the Chinese term “Kauling” meaning high ridge, the name for a hill near Jauchau Fu, where this material was mined centuries ago for ceramics [6]. Figure 2.4 shows the typical view of kaolin. The main constituent, kaolinite is a hydrous aluminium silicate of the approximate composition 2H 2 O, Al 2 O 3 , 2SiO 2 . Kaolinite is the clay minerals which provide the plasticity of the raw material and change during firing to produce a permanent material.
The use of kaolin as a partial cement replacement material in mortar and concrete has been studied widely in recent years [6]. The research work on metakaolin is focused on two main areas. The first one refers to the kaolin structure, the kaolinite to metakaolinite conversion and the use of analytical techniques for the thorough examination of kaolin thermal treatment. The second one concerns the pozzolanic behavior of metakaolin and its effect on cement and concrete properties. The studies done revealed that calcined kaolin (metakaolin) is a very effective pozzolan and results in enhanced strength in the concrete.
14
Figure 2.4 : Kaolin
iv.
Silica Fume
Silica fume (shown in Figure 2.5) which also known as micro silica, is a by product of the reduction of high-purity quartz with coke in electric arc furnaces in the production of silicon and ferrosilicon alloys. Silica fume is also collected as a byproduct in the production of other silicon alloys.
Because of its extreme fineness and high silica content, silica fume is a highly effective pozzolanic material. Silica fume is used as an admixture in Portland cement concretes to improve their qualities. It has been found that silica fume improves compressive strength, bond strength, and abrasion resistance [17].
15
Figure 2.5 : Silica fume
It may be argued that the most important development in concrete production in the last century is the utilization of industrial by-products such as fly ash and ground granulated blast-furnace slag as partial cement replacement materials. This utilization is now extended to other by-products including silica fume and corn cob ash.
The volume of pozzolanic by-products produced world-wide currently exceeds that utilized. Many of these by-products contain toxic elements which can be hazardous if exposed to ground water, when used as land fill or road-bases. Increase in the utilization of pozzolanic materials in concrete comes from greater awareness of current and potential uses of alternative recycled materials and wider realization of the environmental benefits accrued. Such increase in use of waste materials will contribute to the requirements of environmental protection and sustainable construction in the future.
However, it has been reported that the supply of suitable fly ash and slag for blending with cements in some countries is becoming more and more limited. There are compelling reasons to extend the practice of partially replacing cement in concrete and mortar with waste and other that can be found easily and produced much as a
16 waste in our country, which have pozzolanic properties. One possible source for the production of such a pozzolan is rice husk ash.
2.7
Rice Husk Ash
Rice milling generates a by-product know as husk; this surrounds the paddy grain. During the milling of paddy, about 78% is received as rice, broken rice and bran. The remaining 22% is received as husk. This husk is used as fuel in the rice mills to generate steam for the parboiling process. The husk contains about 75% organic volatile matter, leaving 25% to be converted into ash during the firing process, known as rice husk ash (RHA). This RHA contains around 85-90% amorphous silica.
RHA is a good superpozzolan (material with a high silica content of above 85%) and can be used to make special concrete mixes. There is a growing demand for fine amorphous silica in the production of special cement and concrete mixes, high performance, high strength, low permeability concrete, for use in bridges, marine environments, nuclear power plants and much more.
Every 1,000kgs of paddy milled, about 220kgs (22%) of husk is produced and when this husk is burnt in the boilers, about 55kgs of RHA is generated. A ball mill for 30 minutes and its appearance Rice husk was burnt approximately 48 hours under uncontrolled combustion process. The burning temperature was within the range 600 to 8500C. The ash obtained was ground in color was grey (Figure 2.6).
Their physical and chemical characteristics were determined according to the Brazilian ABNT Standards (Table 2.1). In addition, X-ray diffraction was used to verify the presence of crystalline silica in RHA and a laser diffraction particle size analyzer was used to determine the particle size distribution of RHA [13].
17
Figure 2.6 : Rice Husk Ash
Figure 2.7 : X-ray diffractograms of RHA sample.
18 Table 2.1 : Physical and Chemical Properties of RHA. Blaine Specific Surface (cm2/g)
16196
Specific Gravity (g/cm3)
2.16
Mean Particle size
12.34
Passing # 325 (%)
96.6
Chemical Ingredients
SiO 2
92.99
Fe 2 O 3
0.43
Al 2 O 3
0.18
CaO
1.03
MgO
0.35
SaO 3
0.10
Al 2 O 3 + Fe 2 O 3
0.61
SiO 2 + Al 2 O 3 + Fe 2 O 3
93.50
Na 2 O
0.02
K2O
0.72
According to the chemical characteristics, the RHA has high levels of silicon dioxide, approximately 93%, and the specific gravity is 2.16 cm2/g. Figure 2.7 shows x-ray diffractograms for the RHA sample [13]. The results showed a very distinct peak corresponding to crystalline silica. The reason for this behavior is the long time combustion process and the high temperature of burning. According to the Figure 2.8, the average particle size distribution was 12.34m. Thus the RHA is finer than cement and should be expected to work not only a pozzolanic role, but also a microfiller effect
19
Figure 2.8 : Particle size distribution of RHA after 4 hours of grounding.
2.8
Admixtures
The use of chemical admixtures is always necessary when producing SCC in order to increase the workability and reduce segregation. The content of coarse aggregate and the water to binder ratio in SCC are lower than those of normal concrete. Therefore SCC contains large amounts of fine particles such as, blastfurnace slag, fly ash and lime powder in order to avoid gravity segregation of larger particles in the fresh mix.
Admixtures are materials other than cement, aggregate and water that are added to concrete either before or during its mixing to alter its properties, such as workability, curing temperature range, set time or color. Some admixtures have been in use for a very long time, such as calcium chloride to provide a cold-weather setting concrete. Others are more recent and represent an area of expanding possibilities for increased performance.
20 Not all admixtures are economical to employ on a particular project. Also, some characteristics of concrete, such as low absorption, can be achieved simply by consistently adhering to high quality concreting practices. The chemistry of concrete admixtures is a complex topic requiring in-depth knowledge and experience. A general understanding of the options available for concrete admixtures is necessary for acquiring the right product for the job, based on climatic conditions and job requirements. Based on their functions, admixtures can be classified into the following five major categories that are retarding, accelerating, superplasticizers, water reducing and air entraining.
2.8.1
Air-Entraining Admixtures
Air-entraining admixtures are liquid chemicals added during batching concrete to produce microscopic air bubbles, called entrained air, when concrete is mixed. These air bubbles improve the concrete’s resistance to damage caused by freezing and thawing and deicing salt application. In plastic concrete entrained air improves workability and may reduce bleeding and segregation of concrete mixtures. For exterior flatwork (parking lots, driveways, sidewalks, pool decks, patios) that is subject to freezing and thawing weather cycles, or in areas where deicer salts are used, specify a normal air content of 4% to 7% of the concrete volume depending on the size of coarse aggregate. Air entrainment is not necessary for interior structural concrete since it is not subject to freezing and thawing. It should be avoided for concrete flatwork that will have a smooth troweled finish. In high cement content concretes, entrained air will reduce strength by about 5% for each 1% of air added; but in low cement content concretes, adding air has less effect and may even cause a modest increased strength due to the reduced water demand for required slump. Air entraining admixtures for use in concrete should meet the requirements of ASTM C 260, Specification for Air-Entraining Admixtures for Concrete[4].
21 2.8.2
Water Reducing Admixtures
Water reducers are used for two different purposes that are to lower the water content in plastic concrete and increase its strength and the second to obtain higher slump without adding water. Water-reducers will generally reduce the required water content of a concrete mixture for a given slump. These admixtures disperse the cement particles in concrete and make more efficient use of cement. This increases strength or allows the cement content to be reduced while maintaining the same strength. Water-reducers are used to increase slump of concrete without adding water and are useful for pumping concrete and in hot weather to offset the increased water demand. Some water-reducers may aggravate the rate of slump loss with time. Waterreducers should meet the reuirements for Type A in ASTM C 494 Specification for Chemical Admixtures for Concrete[4]. Mid-range water reducers are now commonly used and they have a greater ability to reduce the water content. These admixtures are popular as they improve the finishability of concrete flatwork. Mid-range water reducers must at least meet the requirements for Type A in ASTM C 494 as they do not have a separate classification in an admixture specification.
2.8.3
Accelerating Admixtures
Accelerators reduce the initial set time of concrete and give higher early strength. Accelerators do not act as antifreeze; rather, they speed up the setting and rate of strength gain, thereby making the concrete stronger to resist damage from freezing in cold weather. Accelerators are also used in fast track construction requiring early form removal, opening to traffic or load application on structures. Liquid accelerators meeting requirements for ASTM C 494 Types C and E are added to the concrete at the batch plant [4]. There are two kinds of accelerating admixtures: chloride based and non-chloride based. One of the more effective and economical accelerators is calcium chloride, which is available in liquid or flake form and must meet the requirements of ASTM D 98. For non-reinforced concrete, calcium chloride
22 can be used to a limit of 2% by the weight of the cement. Because of concerns with corrosion of reinforcing steel induced by chloride, lower limits on chlorides apply to reinforced concrete. Prestressed concrete and concrete with embedded aluminum or galvanized metal should not contain any chloride-based materials because of the increased potential for corrosion of the embedded metal. Non-chloride based accelerators are used where there is concern of corrosion of embedded metals or reinforcement in concrete.
2.8.4
Retarders Admixtures
Retarding admixtures slow down the hydration of cement, lengthening set time. Retarders are beneficially used in hot weather conditions in order to overcome accelerating effects of higher temperatures and large masses of concrete on concrete setting time. Because most retarders also act as water reducers, they are frequently called water-reducing retarders. As per chemical admixture classification by ASTMASTM C 494, type B is simply a retarding admixture, while type D is both retarding and water reducing, resulting in concrete with greater compressive strength because of the lower water-cement ratio[4].
Retarding admixtures consists of both organic and inorganic agents. Organic retardants include unrefined calcium, sodium, NH4, salts of lignosulfonic acids, hydrocarboxylic acids, and carbohydrates. Inorganic retardants include oxides of lead and zinc, phosphates, magnesium salts, fluorates and borates. As an example of a retardant's effects on concrete properties, lignosulfate acids and hydroxylated carboxylic acids slow the initial setting time by at least an hour and no more than three hours when used at 65 to 100 degrees Fahrenheit.
23 2.8.5
Superplasticizers Admixtures
Superplasticizers is a special class of water-reducer. Often called high range water-reducers (HRWR), HRWRs reduce the water content of a given concrete mixture between 12 and 25%. HRWRs are therefore used to increase strength and reduce permeability of concrete by reducing the water content in the mixture or greatly increase the slump to produce “flowing” concrete without adding water. These admixtures are essential for high strength and high performance concrete mixtures that contain higher contents of cementitious materials and mixtures containing silica fume. For example, adding a normal dosage of HRWR to a concrete with a slump of 3 to 4 inches (75 to 100 mm) will produce a concrete with a slump of about 8 inches (200 mm). Some HRWRs may cause a higher rate of slump loss with time and concrete may revert to its original slump in 30 to 45 minutes. In some cases, HRWRs may be aded at the jobsite in a controlled manner. HRWRs are covered by ASTM Specification C 494. Types F and G, and Types 1 and 2 in ASTM C 1017 Specification for Chemical Admixtures for Use in Producing Flowing Concrete [4].
2.9
Previous Research on SCC
In order to study the performance of SCC with various materials as a cement replacement material in concrete structures, many works have been conducted throughout the world. Some of the studies conducted are discussed in the following section.
Azhairie, master student from Universiti Teknologi Malaysia, has conducted a study on performance of SCC. The research was implemented to develop and to determine the properties and flexural behaviour of Self Compacting Concrete (SCC) by using Palm Oil Fuel Ash (POFA) as a cement replacement material and admixture (Sika ViscoCrete-15RM). Laboratory test was carried out to investigate the properties of fresh SCC and the strength development of hardened SCC. Six composition of design mix were prepared and tested. The results indicate that POFA and Sika
24 ViscoCrete-15RM are suitable to be used together in producing SCC. The properties and strength development of the produce SCC fulfilled the requirements to be classified as SCC. The SCC also shows higher compressive strength as compared to normal concrete. The flexural strength of the SCC beam indicates a comparable behaviour to normal concrete beam at lower loads. However, the SCC beam achieves higher ultimate strength and showed large ductile behaviour compared to normal concrete beam[3].
A researcher from University of Wolverhampton, United Kingdom named Khatib also has conducted a series of test to study the performance of SCC containing fly ash (FA). In this research, Portland cement (PC) was partially replaced with 0– 80% FA. The water to binder ratio was maintained at 0.36 for all mixes. Properties included workability, compressive strength, ultrasonic pulse velocity (V), absorption and shrinkage. Khatib concluded that high volume FA can be used in SCC to produce high strength and low shrinkage. Replacing 40% of PC with FA resulted in strength of more than 65 N/mm2at 56 days. High absorption values are obtained with increasing amount of FA, however, all FA concrete exhibits absorption of less than 2%. There is a systematic reduction in shrinkage as the FA content increases and at 80% FA content, the shrinkage at 56 days reduced by two third compared with the control. A linear relationship exists between the 56 day shrinkage and FA content. Increasing the admixture content beyond a certain level leads to a reduction in strength and increase in absorption. The correlation between strength and absorption indicates that there is sharp decrease in strength as absorption increases from 1 to 2%. After 2% absorption, the strength reduces at a much slower rate [17].
In Polytechnic University of Valencia, Spain, a group of researcher leads by Valcuende and Parra have carried out a study to investigate the bond behaviour in SCC. Their main objective was to examine the bond strength between reinforcement steel and concrete, and the top-bar effect in self-compacting concretes. Eight different concretes were used, four self-compacting (SCC) and four normally-vibrated (NVC). Tests were conducted on 200 mm cube specimens and 1500 mm high columns. They found that, at moderate load levels, SCC performed with more stiffness, which resulted in greater mean bond stresses. The ultimate bond stresses are also somewhat greater although, due probably to the negative effects of the bleeding having less
25 impact on failure, the differences between SCC and NVC are reduced considerably, and even disappear completely for concretes of more than 50 MPa. On the other hand, the top-bar effect is much less marked in SCC, and therefore a change in the factor that takes into account this effect in the formulas used for calculating the anchorage length of the reinforcement is proposed for these concretes [7].
From these previous researches, the applications of various materials as a cement replacement material or work as a microfiller effect have a different effect on concrete. Research and development of SCC need to be widely studied according to applications in structural engineering.
CHAPTER 3
METHODOLOGY
3.1
Introduction
This chapter describes the materials used, the preparation of the test specimens and the test procedures. Also, the sample or concrete mix proportions were listed down in this section.
In order to achieve the stated objectives, this study was carried out in few stages. On the initial stage, all the materials and equipments needed must be gathered or checked for availability. Then, rice husk ash was used in the concrete mixes according to the predefined proportions. Once the equipment ready, the test will be done for every proportions mixed. Finally, the results obtained were analyzed to draw out conclusion. The flow chart of all the stages was as indicated in Figure 3.1.
27
DATA COLLECTION
PREPARING CONCRETE MIXES
TESTING CONCRETE
RESULT ANALYSIS
CONCLUSIONS AND RECOMMENDATIONS Figure 3.1: Flow chart of the research laboratory work
3.2
Experimental Program
The purpose of the present investigation is to study the properties and flexural behavior of SCC using RHA and admixtures. The cube size 100 x 100 x 100 mm is used to test the compression strength while rectangular beam size 100 x 200 x 1500 mm is used to test the flexural strength. Testing on specimens was conducted on different percentages of RHA as designated. The strength and other results were also compared to specimen that did not contain RHA that acted as control specimen. In all 108 specimens comprise of 3 rectangular beams and 106 cubes were prepared which contains 12 cubes for every sample.
28 3.3
Instrumentations and Laboratory Works
3.3.1
Raw Material
Materials listed below were used in the preparation of the specimen in this study:
3.3.1.1 Cement
Ordinary Portland cement complying with BS 12 British Standards Institution, 1991 was used. When cement mixed with a little water it forms a paste. The mixture is known as a paste because it is actually the means of binding the ingredients of mortar and concrete together, making a rocklike mass. The paste will surround the other ingredients of the concrete and then hardens and grips material in contact with it. The cement was kept in an airtight container and stored in the humidity controlled room to prevent cement from being exposed to moisture. The chemical and physical properties of this material were shown in Table 3.1.
29 Table 3.1 : Properties of Cement Parameters
Cement ( % )
Silica (SiO 2 )
19.757
Alumina (Al 2 O 3 )
5.591
Iron Oxide (Fe 2 O 3 )
3.393
Calcium Oxide (CaO)
62.561
Magnesium Oxide (MgO)
1.233
Sulphur Trioxide (SO 3 )
0.2
(P 2 O 5 )
0.078
(N 2 O)
0.019
Loss On Ignition
2.144
Lime Saturated factor
0.9498
3.3.1.2 Fine Aggregate
Fine aggregate is commonly known as sand should comply with coarse, medium, or fine grading requirements of MS: 30 Part 2, 1995. When the sand contains both fine and course grains, the smaller grains fill the voids between the larger grains, thus binding the aggregate particles together to form a strong concrete. The fine aggregate was air dried to obtain saturated surface dry condition to ensure the water cement ratio is not affected. In this study, sand was used and sieve analysis was done prior to using it to determine the fine aggregate passing 600 m sieve. This was the percentage needed for the mix design calculation.
30 3.3.1.3 Coarse Aggregate
The aggregate component of a concrete mix occupies 60 to 80 percent of the volume of concrete, and their characteristics influence the properties of the concrete. The coarse aggregate was air dried to obtain saturated surface dry condition to ensure that water cement ratio was not affected. Few characteristic of aggregate that affect the workability and bond between concrete matrix are shape, texture, gradation and moisture content. In this study crushed aggregates from quarry with the nominal size 10 mm in accordance to BS 882, 1992 were used.
3.3.1.4 Water
Dry Portland cement does not posses the cementing property, for it is a hydraulic material. The chemical reaction between the compounds of cement and water yields products that achieve the cementing property after hardening is called hydration. Hence the water used should not have any substance that might affect the chemical reaction between the compounds of cement and water. Usually, drinking water from the tap can be used.
3.3.1.5 Rice Husk Ash
The decision to use rice husk ash (RHA) as a cement replacement material is the key element of this research. RHA being selected to determine its suitability to produce SCC due to this ash has pozzolanic properties and similar characteristic to other cement replacement materials that usually being used in producing SCC. Husk is obtained as a by-product of threshing padi. In fact, about 20% of the dry mass of harvested padi is husk. Of this residue, somewhere between 17% and 23% by weight is left as ash when the husk is burned. The ash is about 95% pure silica, and, if properly prepared, it is in an active form which behaves very much like cement.
31
Rice husks contain organic substances and 20% of inorganic material. Rice husk ash (RHA) is obtained by the combustion of rice husk. The most important property of RHA that determines pozzolanic activity is the amorphous phase content. RHA is a highly reactive pozzolanic material suitable for use in lime-pozzolana mixes and for Portland cement replacement. RHA contains a high amount of silicon dioxide, and its reactivity related to lime depends on a combination of two factors, namely the non-crystalline silica content and its specific surface.
For this research, The RHA used in is grayish in colour, becoming dark with increasing proportions of unburnt carbon. It was ground for 4 hours by AIT rod mill to a suitable fineness which in this research up to 45 m before it can be used in the SCC mix. It is kept in airtight container and stored in a humidity-controlled room to prevent it from being exposed to moisture.
3.3.1.6 Admixture
Admixture used in this research is a product obtained from the Sika Kimia Sdn Bhd known as Sika ViscoCrete-15RM to produce SCC. Sika ViscoCrete-15RM is a third generation superplasticizer for concrete and mortar. It meets the requirements for set retarding or high range water reducing superplasticizer according to EN 934-2.
The colour of the Sika ViscoCrete-15RM is brownish. It is categorized as chemical base superplasticizer which made from modified polycarboxylate in water. The recommended dosage for concrete is 0.4 - 1.5% by weight of cement. However, in this research, the dosage are varies to determine the optimum volume of Sika ViscoCrete-15RM which can produce SCC with the highest workability and strength.
Sika ViscoCrete-15RM is especially suitable for the production of ready mixed and suite batched concrete with extended transportation times and extended workability
requirements,
ultra
high
water
reduction
and
excellent
flow
characteristics. Sika ViscoCrete-15RM does not contain chlorides or any other
32 ingredients which promote the corrosion of steel. It is therefore suitable for use in reinforced and prestressed concrete structures.
3.4
Specimen Preparation
In this stage, the description of each process is described in the following sections related to mix composition, samples preparation, moulds and formworks.
3.4.1
Concrete Mixes
For this study, nine different mixes were prepared. To achieve the research objectives, nine samples of mixes are prepared in various mix concrete proportion with constant water-cement ratio. These were subdivided into three groups: Control Concrete, 1% and 1.5% admixtures. For each group, dosage of RHA was varied from 5% to 10% with an increment of 2.5%. The designation of mixes by specific names is explained in the Figure 3.2. The cubes samples are tested with compression test at 1, 7, 14 and 28 days by water curing method.
33
Figure 3.2 : Mix designation
3.4.2
Specimens
The details of the samples and mixtures are shown in Table 3.2(a) and 3.2(b) respectively.
Table 3.2(a) : Concrete mix composition Mix name
Water
Cement
RHA
(kg/m3) (kg/m3) (kg/m3)
Fine
Coarse
Aggregate Aggregate (kg/m3)
(kg/m3)
Admixtures
Water/Binder ratio
CC0.5
200
526
0
875
750
0.5
0.38
CC1.0
200
526
0
875
750
1.0
0.38
CC1.5
200
526
0
875
750
1.5
0.38
5R1.0
200
500
26.3
875
750
1.0
0.38
7.5R1.0
200
486.6
39.5
875
750
1.0
0.38
10R1.0
200
473.4
52.6
875
750
1.0
0.38
5R1.5
200
500
26.3
875
750
1.5
0.38
7.5R1.5
200
486.6
39.5
875
750
1.5
0.38
10R1.5
200
473.4
52.6
875
750
1.5
0.38
34 Table 3.2(b) : Detail of beam mix composition Cement
Sand
Course
Water
RHA
ADMX
(kg)
(kg)
Agg. (kg)
(kg)
(kg)
(mL)
BCC0.5
21.0
35
30
8.0
-
105
0.38
BCC1.0
21.0
35
30
8.0
-
210
0.38
5BR1.0
20.0
35
30
8.0
1.1
210
0.38
Beam
3.4.3
W/b
Mixing Process
Mixing was carried out similar to the mixing of normal concrete. The mixing procedures were divided into three stages. In the first stage, all the materials used (cement, sand, coarse aggregates, water, RHA and admixtures) are weighted accordingly. The second stage involves mixing all components except water and admixture respectively using concrete mixer (Figure 3.3) in dry condition until all the constituents mixed uniformly. At the final stage, measured water and admixture respectively is added into the concrete mix. This step was crucially important to make sure that the water and admixture respectively is distributed evenly so that the concrete mixes will have similar water-binder ratios for every cube. After that, the concrete was then poured into the moulds and formworks.
35
Figure 3.3 : Concrete mixer
3.4.4
Placing Process
The placing process of the concrete mix as shown in Figure 3.4 and 3.5 is the most critical moment. For samples which need in compacted condition, the normal compaction procedure applied. The concrete is poured into the cubes mould in three layers where each layer is compacted 25 times using a steel bar. Whereas, for SCC mixes which requires not any compaction works, the mixes being poured into the cubes mould at a minimum height of 300 mm until its fully filled the space. The cubes are removes from the moulds after 24 hours for curing process.
In placing the concrete mixes in beam formworks, the same process being applied for both compacted and non compacted conditions between NC and SCC mixes respectively. For casting the normal concrete beam, vibrator was used in the compaction work, while the SCC beam not requires any special tool since it spread by
36 its own weight throughout the formworks. Then beams are then ready for curing process.
Figure 3.4 : Placing process
Figure 3.5 : Beams and cubes after placing process
37 3.4.5
Curing Process
Curing condition is very important in gaining the designed strength of concrete. After demoulding, the cubed specimens were cured in water in curing tank (Figure 3.6) before testing for 1, 7, 14 and 28 days according to BS 1881: Part 111, 1983. While for the beams were curing using wetted gunnysacks (Figure 3.7) at room temperature. The continued hydration of cement requires moisture and this is provided by proper curing.
Figure 3.6 : Water tank curing
Figure 3.7 : Gunnysacks curing for beams
38 3.5
Test Instrumentations and Procedurs
Test on concrete consists of test for both fresh and hardened concrete.
3.5.1
Test on Fresh Concrete
It is important that the specimens of concrete to be tested be representative specimens. ASTM makes provision for sampling fresh concrete in C 172 [4]. The specimen must be tested within 15 minutes and during testing must be protected from the weather. Test methods applied to investigate the properties of fresh SCC mixes consists of slump flow test, slump flow T50 test, slump test, L-box test and sieve stability test.
3.5.1.1 Slump Flow Test and Slump Flow T50 Test
The slump flow test and slump flow T50 test are used to assess the filling ability of the concrete. The equipment is shown in Figure 3.8 are as follows:
1) Mould in the shape of a truncated cone with the internal dimensions 200 mm diameter at the base, 100 mm diameter at the top and a height of 300 mm. 2) Base plate of a stiff non-absorbing material, at least 700mm square, marked with a circle marking the central location for the slump cone, and a further concentric circle of 500mm diameter. 3) Trowel. 4) Scoop. 5) Ruler. 6) Stopwatch (optional).
39
Figure 3.8 : Slump flow test and slump flow T50 test equipment.
Figure 3.9 : Slump flow test
40 The procedures of conducting slump flow test and slump flow T50 test are as follows:
1) About 6 liter of concrete is needed to perform the test, sampled normally. 2) Moisten the base plate and inside of slump cone, 3) Place base plate on level stable ground and the slump cone centrally on the base plate and hold down firmly. 4) Fill the cone with the scoop. Do not tamp, simply strike off the concrete level with the top of the cone with the trowel. 5) Remove any surplus concrete from around the base of the cone. 6) Raise the cone vertically and allow the concrete to flow out freely as shown in Figure 3.9. 7) Simultaneously, start the stopwatch and record the time taken for the concrete to reach the 500 mm spread circle. (This is the T50 time). 8) Measure the final diameter of the concrete in two perpendicular directions. 9) Calculate the average of the two measured diameters. (This is the slump flow in mm). Note any border of mortar or cement paste without coarse aggregate at the edge of the pool of concrete.
3.5.1.2 Slump Test
ASTM C143 test for slump of Portland cement concrete details the procedure for performing Slump tests (Figure 3.10) on fresh concrete [4]. A slump cone is filled in three layers of equal volume so the first layer is about 4 in. (76 mm) high, and the second layer is 6 in. (155 mm) high. Each layer is rodded 25 times with a tamping rod 24 in. (600 mm) long and 0.63 in (16 mm) diameter, with a hemispherical tip with 16mm diameter. The rodding is uniformly distributed and full depth for the first layer and just penetrating previous layers for the second and third layers. If the level of concrete falls below the top of the cone during the last rodding, additional concrete is required to keep an excess above the top of the mold. Strike off the surface of concrete by a screeding motion and rolling the rod across the top of the cone. In 5 ± 2 seconds, raise the cone straight up. Set the slump cone next to the concrete, and
41 measure the difference in height between the slump cone and the original center of the specimen. With the rod set on the cone, this slump measurement can be read to the nearest 0.23 in. (6mm). The test from filling of the slump cone to measuring the slump should take no longer than 2 minutes. If two consecutive tests on a sample show a falling away of a portion of the sample, the concrete probably lacks the cohesiveness for the Slump test to be applicable.
Figure 3.10 : Slump test
42 3.5.1.3 L-Box Test
The L box test is used to assess the passing ability of the concrete. The equipment and dimensioning are shown in Figure 3.11 and Figure 3.12 respectively is as follows:
1) L box of a stiff non absorbing material. 2) Trowel. 3) Scoop. 4) Stopwatch.
Figure 3.11 : L box test equipment.
43
Figure 3.12 : The L-box dimension
The procedures of conducting L box test are as follows:
1) About 14 liter of concrete is needed to perform the test, sampled normally. 2) Set the apparatus level on firm ground, ensure that the sliding gate can open freely and then close it. 3) Moisten the inside surfaces of the apparatus, remove any surplus water. 4) Fill the vertical section of the apparatus with the concrete sample. 5) Leave it to stand for 1 minute. 6) Lift the sliding gate and allow the concrete to flow out into the horizontal section. 7) Simultaneously, start the stopwatch and record the times taken for the concrete to reach the 200 and 400 mm marks. 8) When the concrete stops flowing, the distances “H1” and “H2” are measured. 9) Calculate H2/H1, the blocking ratio. 10) The whole test has to be performed within 5 minutes.
44 3.5.1.4 Sieve Stability Test
The sieve stability test is used to assess the segregation resistance (stability) of the concrete. The equipment are as follows:
1) 10 liter bucket with lid. 2) mm sieve 350 mm diameter. 3) Sieve pan. 4) Balance, accuracy 20 g minimum capacity 20 kg. 5) Stopwatch.
The procedures of conducting sieve stability are as follows:
1) About 10 liter of concrete is needed to perform the test, sampled normally. 2) Allow the concrete in the bucket to stand for 15 minutes covered with a lid to prevent evaporation. 3) Determine the mass of the empty sieve pan 4) Inspect the surface of the concrete if there is any bleeding water and note it. 5) Pour the top 2 liter or approximately 4.8 kg ± 0.2 kg only of the concrete sample within the bucket into a pouring container. 6) Determine the mass of the filled pouring container. 7) Determine the mass of the empty sieve pan. 8) Pour all the concrete from the pouring container onto the sieve from a height of 500 mm in one smooth continuous movement. 9) Weigh the empty pouring container. 10) Calculate mass of concrete poured onto sieve, Ma (the difference between the weights full and empty). 11) Allow the mortar fraction of the sample to flow through the sieve into the sieve pan for a period of 2 minutes. Remove sieve and determine mass of
45 ‘filled’ sieve pan. Calculate mass of sample passing sieve, Mb by subtracting the empty sieve pan mass from the filled sieve pan mass. 12) Calculate the percentage of the sample passing sieve, the segregation ratio: (Mb/Ma) x 100.
3.5.2
Test on Hardened Concrete
As for the strength development of hardened SCC, Two types of test done on hardened concrete which are compressive strength test and flexural strength test. Concrete cubes are prepared for compression test to measure their compressive strength at ages of 1, 7, 14 and 28 days. Sample CC is the control for reference. For the flexural behaviour comparison between the SCC and NC, a total of three comparable beams are prepared for flexural strength test.
3.5.2.1 Compression Test
The compression test was conducted by using compressive test machine (Figure 3.13) at the material lab of Civil Engineering Faculty of UTM as specified in the test method BS 1881-Part 116,1983. An increasing compressive load was applied to the specimen until failure occurred to obtain the maximum compressive load. The specimen dimension was taken before the testing. The testing was carried out for 1, 7, 14 and 28 days specimen after curing.
46
Compressive Strength = P/A Where : P : Ultimate compressive load of concrete (kN) A : Surface area in contact with the platens (mm2)
Figure 3.13 : Compressive strength machine
3.5.2.2 Flexural Test
Flexural strength test gives two important parameters. The first is known as first crack strength, which is primarily controlled by the matrix. The second is known as the ultimate flexural strength or the modulus of rapture, which is determined by the maximum load that can be attained. Rectangular beams were used for this test using the two point loading arrangement specified in the Test method BS 1881-Part 118,1983. While the test was conducted, the development of first crack and the cracking up to the failure was closely observed. Once the specimen fail, reading at the display decrease immediately. Record the maximum reading showed at the display
47 before the specimen failed and measure the distance between the crack to the nearest support.
The test beams are simply supported and were subjected to two, symmetrically placed, point loads. The distance between the two loading points is kept at 350 mm and each shear span was 425 mm. Details of the beams and test setup are shown in Figure 3.14 and 3.15. The beams were suitably instrumented for measuring deflections at three locations including the mid span. The beams are tested by applying of incremental load of about 5 kN until failure. The load was applied by a hydraulic jack placed at the Magnus frame and all deformation readings were captured by a computer data logger at preset load intervals until final collapse.
Figure 3.14 : Detail of beam and flexural test setup
48
Figure 3.15 : Flexural test
CHAPTER 4
RESULTS AND DISCUSSIONS
4.1
Introduction
This following chapter will discuss the properties and strength performance of various mixes that containing different percentage of RHA. All the tests conducted were in accordance with the methods described in chapter three to determine the properties, compressive and also flexural strengths.
Discussion will be carried out into four sections as stated earlier in the objective part. The results are to be discussed and analyzed accordingly to draw out the conclusion later. The four sections mentioned are:
1) The properties of fresh concrete 2) The strength development of hardened concrete 3) The Flexural behaviour 4) Cracking pattern
50 4.2
The Properties of Fresh Concrete
The experiment required for the Self-compacting Concrete (SCC) is generally carried out world wide under laboratory circumstances. The experiments methods are defined in The European guidelines for SCC: Specification, production and use as Slump-Flow, T50 test, L-box test and sieve stability test. It has been observed that whether the rice husk ash (RHA) improves the workability of the concrete or not during the test. The experimental results obtained from the test are presented in Table 4.1 and Figure 4.1 – 4.4. Normal compaction concrete with 106mm slump is mixed for control concrete.
Table 4.1 : Results of fresh concrete test
Concrete Sample
Slump Test (mm)
Sieve Stability Test (%)
T50 Test (sec)
Slump
L-box Test
Flow Test
H 1 (mm) H 2 (mm) H 2 /H 1
(mm)
CC0.5
106
-
-
-
-
-
-
CC1.0
-
11.3
2.71
723
55
49
0.89
5R1.0
-
9.6
2.13
740
56
50
0.89
7.5R1.0
-
9.04
2.56
720
58
48
0.83
10R1.0
-
8.4
2.26
748
54
48
0.9
CC1.5
-
16.7
1.68
823
51
45
0.91
5R1.5
-
14.3
1.58
776
65
53
0.81
7.5R1.5
-
14
1.93
815
57
50
0.87
10R1.5
-
11.8
1.66
826
62
49
0.79
51 For the slump flow test and T50 test, it can be seen that the initial flow of 1.5 percent of superplasticizer increase the workability compared to 1.0 percent of superplasticizer, But segregation easy to occur when the concrete too slurry. It can be assume that using 1.0 percent of superplasticizer is the optimum dosage to fulfill the criteria of SCC. In case of adding RHA, 5 % of RHA is an optimum dosage as a cement replacement material. By the way, it seems like increase the RHA also leads to increasing in workability and higher inefficiency in flowing.
Slump Flow Test Acceptance Range : 650mm-800mm 840
820 Max range
800
Diameter (mm)
780
760
740
720
700
680
660 CC1.0
5R1.0
7.5R1.0
10R1.0
CC1.5
5R1.5
Concrete Sample
Figure 4.1 : Slump flow test result
7.5R1.5
10R1.5
52
T50 test Acceptance Range : 2 sec - 5 sec 3
2.5
Min range
Time (sec)
2
1.5
1
0.5
0 CC1.0
5R1.0
7.5R1.0
10R1.0
CC1.5
5R1.5
7.5R1.5
10R1.5
Concrete Sample
Figure 4.2 : T50 test result
The results for the L-box test show all samples pass the requirement for SCC except for sample 10R1.5 which indicate the ratio of 0.79. All the other sample in this study are achieved adequate passing ability and maintain sufficient resistance to segregation around congested reinforcement area. As for the Sieve stability test, only sample CC1.5 did not pass the requirement. The results indicate that segregation SCC tended to decrease with the increment of adding RHA.
53
L-Box Test Acceptance Range : 0.8-1.0 0.92
0.9
0.88
0.86
0.82 Min range 0.8
0.78
0.76
0.74
0.72 CC1.0
5R1.0
7.5R1.0
10R1.0
CC1.5
5R1.5
7.5R1.5
Concerete Sample
Figure 4.3 : L-Box test result Sieve Stability Test Acceptance Range : 5-15% 18
16 Max range 14
12 percentage(%)
L-Box Ratio
0.84
10
8
6 Min range 4
2
0 CC1.0
5R1.0
7.5R1.0
10R1.0
CC1.5
5R1.5
Concrete Sample
Figure 4.4 : Sieve stability test result
7.5R1.5
10R1.5
10R1.5
54 . From all the test result, it can be concluded that the optimum dosage of superplasticizer and RHA as a cement replacement material to consider self compacted concrete is 1.0% and 5%.
4.3
The Strength Development of Hardened Concrete
The test results of the compressive strength between the control and SCC with rice husk ash are summarized in Table 4.2 and the development of the compressive strength of the entire sample shown in Figure 4.5. Each presented value consists of average of three measurements.
It is evident in Table 4.2 and Figure 4.5 that all the test ages, the use of rice husk ash as a cement replacement material decreased the early strength of the SCC mixes compared to the control. Control sample with compacted concrete give the highest value of compression strength that is 29.8 N/mm2. However, the compressive strength of the SCC with 5% rice husk ash show a significant increment after 7 days compared to the control and 10% rice husk ash. This may be the optimum percent of rice husk ash that can be used as a cement replacement material. In other words, rice husk ash have a properties of hydraulic or pozzolanic activity to contribute to hydration, occur more C-S-H gels and gain compressive strength in concrete with elapsed time. These results are similar to statement of Mahmud (2003) who reported the optimum dosages of rice husk ash are between 5%-10% as a cement replacement material [3].
55 Table 4.2 : Average compressive strength result
Average Compressive Strength, fcu (N/mm2) Concrete
Remarks
Sample
1 day
7 days
14 days
28 days
CC 0.5
29.8
34.8
42.4
53.4
compacted non-
CC 1.0
26.9
44.9
51.9
51.7
compacted non-
CC 1.5
21.4
39.0
45.2
56.9
compacted non-
5 R 1.0
18.2
44.8
53.4
55.2
compacted non-
5 R 1.5
19.6
42.9
42.5
50.3
compacted non-
7.5 R 1.0
10.4
37.2
44.6
50.5
compacted non-
7.5 R 1.5
12.4
30.2
40.2
51.2
compacted non-
10 R 1.0
17.7
33.4
44.6
52.7
compacted non-
10 R 1.5
14.0
33.7
46.2
54.8
* Full compressive results are shown in Appendix A – I.
compacted
Compressive Strength, fcu
0
10
20
30
40
50
60
1 day
days
14 days
Figure 4.5 : Average compressive strength result
7 days
Average Compressive Strength, fcu
28 days
CC 0.5 CC 1.0 CC 1.5 5 R 1.0 5 R 1.5 7.5 R 1.0 7.5 R 1.5 10 R 1.0 10 R 1.5
56
57
Sample 7.5R1.5 and 5R1.5 have a lesser compressive strength at age of 14 and 28 days compared to sample 5R1.0 and 10R1.0. This are maybe because high dosage of admixtures might lead to the creation of pore if concrete is to be compacted under its own self-weight only and also caused segregation. This cause the hardened cubed not compacted perfectly and has a honeycombs that influence the compressive strength. The occurrence of honeycomb due to poor self-compaction can be seen in Figure 4.6(a) and Figure 4.6(b) show cube’s condition when it has good self compaction.
Figure 4.6(a) : Poor self-compaction compaction
Figure 4.6(b) : Good self-
58 4.4
The Flexural Behaviour
Flexural test can be described as the ability of beam to sustain load. This test is most important parameter that to be considered in designing a beam. The results of the flexural test are presented in Table 4.3 and Figure 4.7. The values are taken from the reading of gauge no 2 which locate in the middle span of the beam.
Table 4.3 : Flexural test result Ultimate Load
Maximum Deflection
First Crack
(kN)
(mm)
(kN)
BCC0.5-OPC
85.9
6.91
26
BCC1.0-SCC
111.5
12.11
38
5BR1.0-SCC
91.5
7.31
34
Beam Sample
* Full flexural test results are shown in Appendix K – M
The general examination made from Table 4.3 shows that all the beam sample can sustain the ultimate load from the calculation that is 55 kN. SCC beam have increased the load bearing capacity compared to the control beam which the control beam have a load capacity of 85.9 kN when its failed and both of SCC beam are 111.5 kN for BCC1.0 and 91.5 kN for 5BR1.0. This can be assumed that SCC is effective in increasing the beam’s flexural strength probably caused by good bonding between the reinforcement and concrete. This occurrence may possibly be explain by SCC having a greater fill capacity, which enables them to cover the reinforcements entirely without need of vibrator while the control concrete process depends on the vibration to be compacted perfectly. The greater filling capacity of SCC and its smaller amount of bleeding also reduce the occurrence of voids between the reinforcement and the concrete, with the result that the ribs lean against the concrete more effectively produce greater flexural strength.
However, compared to the dosage of concrete mixing with RHA and not that are BCC1.0 and 5BR1.0. Global observation shows that until 68 kN, the deflection for
59 both SCC beam not show any significant differences. When load of 68 kN and above are putted, sample 5BR1.0 sustain lesser load from BCC1.0 until it failed at load 91.5 kN and 7.31 mm deflection. While sample BCC1.0 continue to sustain more deformation until it failed at 111.5 kN with deflection of 12.11 mm. Although using a optimum dosage of RHA (5%) as a cement replacement material causes an increase in strength, the 5BR1.0 specimen have a small pore or honeycomb maybe due to low efficiency of casting and pouring the concrete into the formwork. It is better to used concrete pump for SCC which has a high workability in order to have good selfcompaction, good distribution concrete and prevent segregation.
Load (kN)
0
20
40
60
80
100
120
0
4
6
Deflection (mm)
8
10
12
Figure 4.7 : Flexural result for all beam-Load(kN) versus deflection (mm)
2
Flexural Test
14
BCC0.5 BCC1.0 5BR1.0
16
60
61 4.5
Crack Patterns
Figure 4.8(a), 4.8(b) and 4.8(c) display the crack pattern of each beam’s sample, includes how much load are putted when the crack happened. The results show crack occurs first at normal concrete beam. Control beam (BCC0.5) showed a small crack at load of 26 kN while the SCC beam have a first crack at 38 kN and 34 kN. This may be due good bonding ability of SCC helps to sustain the beams from being deforms. However, between BCC1.0 and 5BR1.0, there are no significant differences except the ultimate load capacity of the beams. The first crack loads occurred for both beams were almost the same but ultimate load capacity for BCC1.0 is higher than 5BR1.0. From this result, can be concluded that adding rice husk ash as a cement replacement material is not show any significance difference for the flexural strength of the concrete.
Figure 4.8(a) : Crack pattern for BCC0.5
Figure 4.8(b) : Crack pattern for BCC1.0
62
Figure 4.8(c) : Crack pattern for 5BR1.0
4.6
Summary
From the all test that have been done, it can be conclude that using RHA as a cement replacement can improved the quality of concrete if appropriate dosage is used. In this study, the optimum dosage of RHA as a cement replacement material is 5% with 1.0% admixtures by weight of cement. This composition improved both fresh and hardened concrete while not neglect the criteria of SCC. If percentage of RHA and admixtures is used above from the recommend, it will decrease the fresh and hardened concrete’s properties. This is due to void present caused by poor self compaction.
CHAPTER 5
CONCLUSIONS AND RECOMMENDATIONS
5.1
CONCLUSIONS
The usage of rice husk ash in self compacted concrete improved certain aspect in the concrete itself in term of properties and strength. The conclusions are based on the objectives of the research.
1.
The optimum dosage of rice husk ash as a cement replacement material can be said as 5% with 1.0% of Sika Viscocrete 15RM as an admixture in order to obtain sufficient performance for both of fresh and hardened properties of SCC.
2.
The optimum mix design of SCC is found to be from sample 5R1.0 as shown in Table 5.1, with the cement, sand and coarse aggregates mix
3 1 proportion of 1 : 1 : 1 together with 5% of RHA and 1.0% Sika 4 2 ViscoCrete-15RM. Detail composition of sample 5R1.0 as in Table 5.1.
64 Table 5.1 : Sample 5R1.0 composition
3.
Material
Composition
Water
200 kg/m3
Cement
500 kg/m3
RHA
26.3 kg/m3
Fine Aggregate
875 kg/m3
Coarse Aggregate
750 kg/m3
Admixtures (By weight of cement)
1.0%
Water/Binder ratio
0.38
Adding a rice husk ash as a cement replacement material can increase the workability and the ultimate compressive strength of the concrete if using appropriate dosage.
4.
Using rice husk ash as a cement replacement material does not give any significance differences in flexural strength of the self compacted concrete.
5.
Consequently, it can be report that about 5% of RHA as a cement replacement material has also beneficial effects on both fresh and hardened properties of SCC compared to ordinary concretes. Thus, RHA can be recycled at higher amounts, the environmental pollution can be prevented and economical advantages can be provided.
65 5.2
RECOMMENDATIONS
This
study
has
its
own
limitation
and
therefore,
the
following
recommendations are made for future studies to improve, to extend and to explore the current work for development of SCC using rice husk ash as a cement replacement material.
1. Improved the mix by modifying the various constituents to observe the physical and strength changes.
2. This study only used one type of admixtures. It is recommended to use different type of admixtures whether its influences the properties of concrete.
3. More test on the fresh concrete in order to explore various properties of SCC because fresh properties are the most important role in classifying SCC concrete.
4. It is recommended that the compression test to be carried on for 56 days to see the performance of hardened SCC.
66
REFERENCES
1. Kumar. P. Self Compacting Concrete: Methods of Testing and Design. Journal of IE(I). 86:145-150. 2006.
2. Noor Azreena. Ciri-ciri Konkrit Tanpa Getar menggunakan Abu Pembakaran Kelapa Sawit (POFA) dan Bahan Tambah. Tesis Sarjana Muda
Universiti Teknologi Malaysia: 2007.
3. Azhairie Effenddy Azmi. The Properties of Self Compacting Concrete Using Palm Oil Fuel Ash and Admixture. Tesis Sarjana. Universiti Teknologi
Malaysia. 2008.
4. Testing-SCC. Measurement of properties of fresh self compacting concret. University of Paisley, UK, ACM Centre.2005.
5. Reis J.M.L. Fracture and flexural characterization of natural fiberreinforced polymer concrete journal. Universidade Federal Fluminense,
Brasil. 2005.
6. Magendran Subramani. Palm oil fiber as an additive in concrete. Tesis Sarjana Muda. Universiti Teknologi Malaysia. 2007. 7. Valcuende.M1, Parra.C2. Bond behaviour of reinforcement in selfcompacting concretes journal. University of Valencia1 University of
Cartagena2, Spain. 2009.
8. Raghu Prasad.B.K. Prediction of compressive strength of SCC and HPC with high volume fly ash using ANN. Indian Institute of Science,India.2008.
67
9. Mohd Eizzuddin Mahyeddin. Kesan penggunaan abu sekam padi di dalam konkrit tanpa getar. Tesis Sarjana Muda. Universiti Teknologi Malaysia.
2007.
10. Huzaifa Hashim. The effect of palm oil fiber on concrete properties. Tesis Sarjana Muda. Universiti Teknologi Malaysia. 2008.
11. Peter Bartos J.M. Testing SCC-Measurement of properties of fresh self compating concrete.University of Paisley, Scotland. 2003.
12. Mauro M.Tashima,Carlos A.R.da Silva. The possibility of adding the rice husk ash (RHA) to the concrete. Civil Engineering Department,
FEIS/UNESP, Brazil. 2003.
13. Megat Johari Megat Mohd Noor/Azlan Abd Aziz/Radin Umar. Effects of Cement-Rice Husk Ash Mixtures on Compaction,Strength and Durability of Melaka Sereis Lateritic Soil. Universiti Pertanian Malaysia,Serdang. 1988.
14. Narayan P Singharia. Adding to The Mix. S&S Consultants. 15. Shazim Ali Memon. Production of Low Cost Self Compacting Concrete Using Rice Husk Ash. National University of Sciences and Technology,
Pakistan. 2008.
16. Khatib.J,M. Performance of Self-Compacting Concrete Containing Fly Ash. University of Wolverhampton, UK. 2007.
17. Kou S.C/Poon C.S. Properties of Self-Compacting Concrete Prepared with Recycled Glass Aggregate. The Hong Kong Polytechnic University, Hong
Kong. 2008.
68 18. Wang Her-Yung. Durability of Self-Consolidating Lightweight Aggregate Concrete Using Dredge Silt. National Kaohsiung University of Applied
Science, Taiwan. 2008.
19. Hajime Okamura and Masahiro Ouchi. Self Compacting Concrete. Japan Concrete Institute. 2003.
20. Malhotra V.M. Fly Ash, Silica Fume, Slag, & Other Mineral By-product in Concrete. Publication SP-79, American Concrete Institute. 1983.
21. Malhotra, V.M. Fly Ash, Silica Fume, Slag, and Natural Pozzolans In Concrete.
Proceedings
Second
International
Conference,
Madrid,
Spain.1986.
22. Hewlett, Peter. Lea’s Chemistry of Cement and Concrete. Elsevier Butterworth Heinemann.1998.
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
29.8
34.8
42.4
Details of Sample OPC + 0.5% Sika Viscorete 15RM Compacted Fresh Concrete Test Results 106 mm (2 – 5 sec) (650 – 800 mm) (0.8 – 1.0) (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 29.70 30.81 28.95 35.07 38.21 31.05 30.71 45.77 50.80
TEST RESULTS FOR SAMPLE CC0.5
APPENDIX A
53.4
41.90 57.16 61.00
28 days
69
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
26.9
44.9
51.9
Details of Sample OPC + 1.0% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 2.71 sec Ok (2 – 5 sec) 723 mm Ok (650 – 800 mm) 0.89 Ok (0.8 – 1.0) 11.3% Ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 27.77 27.17 25.92 40.28 42.17 52.25 52.57 53.21 50.15
TEST RESULTS FOR SAMPLE CC1.0
APPENDIX B
51.7
48.64 59.84 46.74
28 days
70
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
18.2
44.8
53.4
Details of Sample 5% RHA + OPC + 1.0% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 2.13 sec Ok (2 – 5 sec) 740 mm Ok (650 – 800 mm) 0.89 Ok (0.8 – 1.0) 9.6% Ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 17.28 18.79 18.76 45.57 41.34 47.54 51.56 55.01 53.67
TEST RESULTS FOR SAMPLE 5R1.0
APPENDIX C
55.2
57.58 53.56 54.56
28 days
71
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
10.4
37.2
44.6
Details of Sample 7.5% RHA + OPC + 1.0% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 2.56 sec Ok (2 – 5 sec) 720 mm Ok (650 – 800 mm) 0.83 Ok (0.8 – 1.0) 9.04% Ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 9.25 12.48 9.60 40.23 36.81 34.62 42.51 38.98 52.31
TEST RESULTS FOR SAMPLE 7.5R1.0
APPENDIX D
50.5
48.91 54.35 48.24
28 days
72
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
17.7
33.4
44.6
Details of Sample 10% RHA + OPC + 1.0% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 2.26 sec Ok (2 – 5 sec) 748 mm Ok (650 – 800 mm) 0.90 Ok (0.8 – 1.0) 8.40% Ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 17.69 16.57 18.90 34.71 37.03 28.48 48.32 35.64 49.92
TEST RESULTS FOR SAMPLE 10R1.0
APPENDIX E
52.7
57.85 38.74 61.50
28 days
73
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
21.4
39.0
45.2
Details of Sample OPC + 1.5% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 1.68 sec Not ok (2 – 5 sec) 823 mm Not ok (650 – 800 mm) 0.91 Ok (0.8 – 1.0) 16.7% Not ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 22.70 22.91 18.86 48.02 36.32 32.81 44.14 45.07 46.59
TEST RESULTS FOR SAMPLE CC1.5
APPENDIX F
56.9
60.68 50.12 60.17
28 days
74
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
19.6
42.9
42.5
Details of Sample 5% RHA + OPC + 1.5% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 1.58 sec Not ok (2 – 5 sec) 776 mm Ok (650 – 800 mm) 0.81 Ok (0.8 – 1.0) 14.3% Ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 19.98 20.05 18.90 41.40 43.56 44.03 37.70 51.84 38.24
TEST RESULTS FOR SAMPLE 5R1.5
APPENDIX G
50.3
62.17 41.27 47.67
28 days
75
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
12.4
30.2
40.2
Details of Sample 7.5% RHA + OPC + 1.5% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 1.93 sec Not ok (2 – 5 sec) 815 mm Not ok (650 – 800 mm) 0.87 Ok (0.8 – 1.0) 14.0% Ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 10.84 9.65 16.71 28.74 36.45 25.37 45.24 40.21 35.15
TEST RESULTS FOR SAMPLE 7.5R1.5
APPENDIX H
51.2
48.75 53.25 51.60
28 days
76
Cube 1 2 3 4 5 6 7 8 9 10 11 12 Average Compressive Strength
Slump Test Slump Flow T50 Test Slump Flow Test L-Box Test Sieve Stability Test
Composition Condition
14.0
33.7
46.2
Details of Sample 10% RHA + OPC + 1.5% Sika Viscocrete 15RM Not Compacted Fresh Concrete Test Results 1.66 sec Not ok (2 – 5 sec) 826 mm Not ok (650 – 800 mm) 0.79 Not ok (0.8 – 1.0) 11.8% Not ok (5 – 15%) Hardened Concrete Test Results – Compression Test (kN/m2) 1 days 7 days 14 days 12.59 13.47 15.94 34.16 30.10 37.03 53.92 51.84 33.04
TEST RESULTS FOR SAMPLE 10R1.5
APPENDIX I
54.8
47.83 58.82 57.85
28 days
77
BCC0.5 14 days 28 days BCC1.0 14 days 28 days 5BR1.0 14 days 28 days
Sample/Age
50.2 52.1 51.6 53.6 57.2 61.6
55.78 58.05 43.28 64.41
Average
53.12 49.68
Compression Test (kN/m2) 2 3
1 OPC + 0.5% Sika Viscocrete 15RM 47.83 49.65 46.54 60.23 OPC + 1.0% Sika Viscocrete 15RM 46.89 52.13 42.49 60.43 5% RHA + OPC + 1.0% Sika Viscocrete 15RM 54.68 73.78 54.87 65.54
COMPRESSION TEST RESULTS FOR BEAM’S CUBE
APPENDIX J
78
79 APPENDIX K FLEXURAL TEST RESULT FOR BCC0.5
Load(kN)
0.00 2.30 4.40 6.00 8.00 10.20 12.30 14.20 16.30 18.10 20.00 22.00 24.20 26.10 28.20 30.20 32.00 34.40 36.20 37.90 39.90 42.00 43.90 45.80 48.00 49.80 52.10 54.00 55.80 57.80 59.80 62.20 64.00 66.20 68.40 70.30 71.90 73.80 75.80 78.00
Deflection (mm)
Remarks
Gauge1 Gauge 2 Gauge 3 0.00 0.00 0.00 0.19 0.24 0.28 0.29 0.38 0.40 0.39 0.45 0.44 0.49 0.52 0.52 0.59 0.59 0.60 0.59 0.64 0.58 0.69 0.71 0.64 0.69 0.80 0.73 0.79 0.89 0.83 0.89 1.01 0.93 1.00 1.15 1.06 1.10 1.27 1.20 1.21 1.40 1.31 First crack 1.40 1.60 1.51 1.50 1.76 1.66 1.62 1.90 1.78 1.80 2.04 1.93 1.89 2.23 2.10 2.00 2.31 2.17 2.10 2.44 2.30 2.19 2.58 2.38 2.39 2.73 2.52 2.50 2.89 2.66 2.70 3.07 2.84 2.80 3.21 2.96 3.00 3.42 3.15 3.10 3.58 3.30 3.32 3.86 3.58 3.50 4.09 3.77 3.70 4.27 3.93 3.90 4.49 4.12 4.02 4.66 4.28 4.40 4.97 4.56 4.60 5.17 4.76 4.71 5.29 4.86 4.81 5.48 5.04 5.01 5.66 5.21 5.21 5.92 5.48 5.41 6.16 5.70
80
FLEXURAL TEST RESULT FOR BCC0.5 - CONT
Deflection (mm) Load(kN) 80.00 81.90 84.10 85.90 72.00 72.00
Remarks Gauge1 Gauge 2 Gauge 3 5.61 6.32 5.84 5.73 6.50 6.01 5.91 6.71 6.22 6.11 6.91 6.40 7.49 9.27 9.54 7.50 9.27 9.55
Beam failure
81 APPENDIX L FLEXURAL TEST RESULT FOR BCC1.0
Deflection(mm) Load(kN) 0.00 2.60 4.10 6.20 8.50 10.00 12.20 14.00 16.20 18.10 20.10 20.40 22.10 24.00 26.20 28.10 30.20 32.00 34.40 36.20 38.10 38.40 40.20 42.20 44.10 46.50 48.40 50.50 52.20 54.00 56.20 58.60 60.40 62.00 64.00 66.00 68.10 70.00 72.00 73.90
Remarks Gauge 1 Gauge 2 Gauge 3 0.00 0.00 0.00 0.10 0.20 0.28 0.20 0.30 0.39 0.30 0.39 0.47 0.40 0.45 0.53 0.40 0.49 0.58 0.50 0.55 0.64 0.50 0.60 0.68 0.60 0.66 0.74 0.60 0.70 0.78 0.70 0.81 0.88 0.72 0.84 0.91 0.80 0.91 0.97 0.89 1.03 1.06 1.09 1.20 1.18 1.20 1.34 1.30 1.29 1.46 1.41 1.39 1.60 1.51 1.53 1.73 1.64 1.63 1.85 1.72 1.79 1.97 1.83 1.81 2.06 1.90 1.89 2.14 1.97 1.99 2.27 2.08 2.12 2.41 2.19 2.29 2.55 2.33 2.39 2.67 2.44 2.49 2.83 2.59 2.59 2.93 2.68 2.69 3.07 2.80 2.88 3.19 2.96 2.98 3.33 3.09 3.16 3.49 3.23 3.18 3.58 3.32 3.38 3.72 3.44 3.48 3.85 3.55 3.58 3.98 3.68 3.68 4.12 3.81 3.81 4.26 3.94 3.98 4.39 4.07
First crack
82 FLEXURAL TEST RESULT FOR BCC1.0 - CONT
Deflection(mm) Load(kN) 76.00 78.20 80.20 82.10 84.10 86.00 88.20 89.90 92.40 93.90 96.00 98.20 99.80 101.80 103.80 105.70 107.50 109.80 111.20 111.50 78.10
Remarks Gauge 1 Gauge 2 Gauge 3 4.38 4.70 4.33 4.47 4.87 4.48 4.67 5.01 4.61 4.81 5.21 4.66 4.97 5.35 4.79 5.07 5.48 4.91 5.27 5.67 5.08 5.37 5.82 5.23 5.61 6.07 5.47 5.77 6.22 5.59 5.96 6.41 5.78 6.16 6.65 5.99 6.20 6.82 6.15 6.56 7.11 6.42 7.15 7.82 6.98 7.76 8.64 7.58 8.45 9.33 8.18 9.64 10.59 9.14 10.77 11.70 10.08 11.13 12.11 10.44 12.22 14.40 13.74
Beam failure
83
APPENDIX M FLEXURAL TEST RESULT FOR 5BR1.0
Load(kN)
0.00 2.10 4.00 6.50 8.20 10.10 12.80 14.00 16.00 17.90 20.00 22.00 24.20 26.00 28.00 30.10 32.00 34.10 36.20 38.20 40.10 42.10 44.00 46.00 48.00 50.10 52.00 53.90 56.00 58.10 60.60 62.00 64.10 66.10 68.70 70.20 72.00
Deflection(mm)
Remarks
Gauge 1 Gauge 2 Gauge 3 0.00 0.00 0.00 0.10 0.06 0.21 0.20 0.19 0.34 0.23 0.31 0.46 0.31 0.36 0.51 0.32 0.41 0.57 0.40 0.47 0.64 0.40 0.51 0.68 0.50 0.57 0.75 0.52 0.64 0.82 0.61 0.71 0.90 0.70 0.78 0.99 0.80 0.89 1.09 0.90 0.99 1.19 1.01 1.13 1.31 1.21 1.32 1.47 1.24 1.42 1.56 1.41 1.55 1.68 First crack 1.51 1.68 1.81 1.61 1.78 1.90 1.71 1.91 2.03 1.83 2.07 2.18 1.94 2.19 2.28 2.11 2.35 2.43 2.23 2.52 2.60 2.41 2.68 2.76 2.51 2.79 2.85 2.61 2.94 3.00 2.81 3.12 3.19 3.01 3.29 3.35 3.11 3.44 3.50 3.21 3.56 3.60 3.51 3.82 3.86 3.65 3.98 4.01 4.01 4.28 4.31 4.11 4.42 4.43 4.34 4.65 4.66
84
FLEXURAL TEST RESULT FOR 5BR1.0 - CONT
Deflection(mm) Load(kN) 73.90 75.90 78.60 80.50 81.90 84.80 86.30 88.20 89.90 91.50 91.50 90.30 82.40 79.70
Remarks Gauge 1 Gauge 2 Gauge 3 4.52 4.79 4.81 4.64 4.96 4.83 4.92 5.20 5.06 5.04 5.39 5.22 5.22 5.58 5.40 5.52 5.83 5.64 5.72 6.04 5.81 7.13 6.95 6.52 7.25 7.12 6.56 7.53 7.31 6.72 Beam failure 7.93 7.63 6.93 8.15 7.82 7.11 8.42 8.01 7.28 8.50 8.18 7.35
