HIGH VOLUME HIGH PERFORMANCE FLY ASH CONCRETE MIX DESIGN FOR PAVEMENT OVERLAYS FOR SUSTAINABLE DEVELOPMENT PDF

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International Journal of Civil Engineering and Technology (IJCIET) Volume 7, Issue 6, November-December 2016, pp. 592–601, Article ID: IJCIET_07_06_066 Available online at http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=6 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © I...

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International Journal of Civil Engineering and Technology (IJCIET) Volume 7, Issue 6, November-December 2016, pp. 592–601, Article ID: IJCIET_07_06_066 Available online at http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=6 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication

HIGH VOLUME HIGH PERFORMANCE FLY ASH CONCRETE MIX DESIGN FOR PAVEMENT OVERLAYS FOR SUSTAINABLE DEVELOPMENT B. H. Manjunath Department of Civil Engineering, Faculty of Sri Siddhartha Institute of Technology Sri Siddhartha Academy of Higher Education, Tumakuru Dr. A. V. Pradeepkumar Department of Civil Engineering, Professor & Head of the Department of JNNCE, Visvesvaraya Technological University, Belagavi Rahulraj. M Department of Civil Engineering, Project Student, PESIT, Visvesvaraya Technological University, Belagavi ABSTRACT A well deigned pavement has to perform to its full designed life. Many times premature failure may occur to a well-designed pavement. Any pavement is required to have maximum useful life, with minimum maintenance, and certain structural and functional requirements are to be full filled till the end of design life. But inadequacy in structural or functional requirements leads to improper functioning and failure of pavement and it is known as "Distress". Formation of cracking is a distress; it may be due combined action of traffic loads and environmental factors. To maintain structural integrity of pavement, it is essential to prevent or retard these cracks. Overlay is one such most economical form of maintenance work, which prolongs the life of pavement. But cracks of distress may propagate and reappear in the new surface, due to traffic load and temperature induced fatigue, through and on the surface of overlay. This is known as "Reflection cracking”. This reflection cracking can be controlled to some extent and its life can be prolonged, by using reasonably good quality overlay. In this context here an attempt is made to design high volume high performance flyash concrete, with available local materials, for pavement overlay, which possess good paving properties and is sustainable Key words: Control concrete, Fly ash concrete, HVHPFAC, Overlay, Mix design. Cite this Article: B. H. Manjunath, Dr. A. V. Pradeepkumar and Rahulraj. M, High Volume High Performance Fly Ash Concrete Mix Design for Pavement Overlays for Sustainable Development. International Journal of Civil Engineering and Technology, 7(6), 2016, pp.592–601. http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=6

1. INTRODUCTION Concrete is the ultimate choice for most structural applications, due to its low cost, easy availability, versatility and intended engineering properties. The cement demand in the world is continuously http://www.iaeme.com/IJCIET/index.asp

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increasing. It was 2million tones in the year 1880 and 407millions in 2017.production of every tone of portland cement releases approximately same amount of carbon dioxide to the atmosphere which is a main concern to greenhouse gas effect, responsible for global warming [1]. India and china are the two countries with rich resources of coal, have established coal-fired power stations to generate electricity to meet the demand of people and industries, which contribute much to the global warming. In the early 80s, the safe disposal of flyash itself was a big problem, about 80% of flyash produced in those days was simply disposed of by ponding and stockpiling due low usage of these material. Nowadays getting flyash itself is difficult due to the high demand of flyash from various sectors of production and construction. In view of global sustainable development, it is imperative that, the materials like flyash should be used for benefit in huge quantities. The concrete construction industry is one, which can consume these materials safely and beneficially, results in reduction of pollution, conversion of industrial waste to a utility, problem of disposal is reduced and production of cost effective construction materials. There is a lot of scope to utilize the flyash in road sector. Because of the initial cost, concrete roads did not attract the attention of highway technologists in the early 80s, but nowadays awareness is developed regarding long range benefits of concrete roads. Many research works have shown that, use of fly ash in large quantities in concrete imparts several advantages. The concrete with flyash more than 50% is regarded as ‘high volume flyash concrete [2].fly ash contains reactive constituents and unreactive crystalline matter. The reactive portion chemically reacts with lime and offers hydrated mineralogy to impart strength, and unreactive crystalline matter gives packing effect to the mortar/concrete, filling up the pores, and there by increases the strength[2] and addition of flyash improves various properties of concrete like compressive strength, flexural strength, modulus of elasticity,etc., according to aitcin.p.c (1998),reducing water/binder ratio, and using supplementary cementations materials, the weakness of the transition zone can be reduced. Thus use of calcium based fly ash improves micro-structure in concrete [3]. The concrete of grade m60 and more is referred as high strength concrete [3].aitcit.p.c defines high strength concrete with high volume flyash as ‘high performance flyash concrete. Depending upon the 28 day strength, hpc’s are classified as follows [3]. 1. Hpc, with strength range 50-100 mpa 2. Very high performance concrete, with strength range 100-150 mpa 3. Hyper performance concrete, with strength range >150 mpa Generally concrete pavements are built with m40 grade concrete [4]. But, in many cases, because of many reasons, even, a well-designed pavement will not sustained to its full designed life. In such situations its life is prolonged by providing an overlay. An overlay is the additional thickness provided to strengthen or increase the load carrying capacity or life or both of the existing distressed the pavement [5]. The distressed pavement will have minor and major cracks on the surface and are likely to propagate and reappear in the overlay. The propagation of cracks is due to traffic induced vertical movements and environmental induced horizontal movements [6]. The complete arrest of propagation of cracks from existing pavement to the overlay is not possible, but it can be delayed by providing better quality material as overlay. In this view here an attempt is made to design ‘high volume high performance flyash concrete of m60 grade for overlay. Here an attempt is made to design m60 grade high volume high performance flyash concrete for overlays, for sustainable development.

2. MAIN OBJECTIVE High strength concrete with high volume flyash is regarded as high performance concrete. This concrete has one or more of properties like low shrinkage, low permeability, high flexural strength and high modulus of elasticity, which are the essence of desirable requirements of an overlay. In this view the main objective of the present study is to design ‘high volume high performance flyash concrete of strength 60 Mpa for rigid pavement overlays. As more than 50% flyash is proposed to use, this may leads to sustainable development. For the present study flyash is added without corresponding reduction in the

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High Volume High Performance Fly Ash Concrete Mix Design for Pavement Overlays for Sustainable Development

quantity. The main advantage of this method of use of flyash is, effective cementitious content of concrete is increased and exhibits increased strength at all ages of concrete mass [7], is desirable for pavement and pavement overlays. In this study IS: 10262-2009 guide lines are followed for the mix design.

3. EXPERIMENTAL PROGRAMME The materials used for HVHPFAC of M60 grade does not much differs from normal concrete, except HVHPFAC contains a high-range water reducer or super plastisiser. Various materials used for the production of HVHPFAC are subjected basic tests to confirm its compliance with the specifications of IS code. Different size aggregates are blended, analytically to achieve the best gradation, by trial and error method. Throughout the experimental studies locally available materials are used, and they have following properties.

3.1. Cement Ordinary Portland cement, 43grade is used in the present studies, which conforms to IS 8112-1989.The physical properties of cement are as shown in the table-1. Table 1 physical properties of cement. Sl. No. 1. 2. 3. 4. 4. 5.

6.

Test

Results

Normal consistency

32%

Initial setting time Final setting time Fineness (Blaine’s air permeability) Specific gravity

Not specified

102 min.

Shall not be less than 30 minutes

398 min.

Shall not be more than 600 minutes

295 m2/Kg 3.14

Soundness (Lechatelier’s method) Compressive strength

Requirements as per IS: 8112-1989

1.75 mm

Not less than 225m2/Kg Not specified Shall not be more than 10mm

a) 3days

26.8 N/mm2

Shall not be less than 23 N/mm2

b) 7days

37.5 N/mm2

Shall not be less than 33 N/mm2

c) 28days

49.8 N/mm2

Shall not be less than 43 N/mm2

3.2. Fine Aggregate Locally available natural sand is used as fine aggregate, which confirms to zone-II as per IS: 383-1970.The physical properties of sand are shown in the table-2.

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B. H. Manjunath, Dr. A. V. Pradeepkumar and Rahulraj. M Table 2 Physical properties of sand IS Sieve size in (mm)

Weight retained (gm)

Percentage weight retained

Cumulative percentage weight retained

4.75

34

1.7

1.7

2.36

30

1.5

3.2

1.18

370

18.5

21.7

0.6

685

34.25

55.95

0.3

745

37.25

93.2

0.15

120

6.0

99.2

Pan

16

0.8

100

Total (Excluding pan)

274.95

Fineness Modulus

2.74

Specific gravity

2.57 3

Unit weight Kg/m

1680

3.3. Coarse Aggregate The coarse aggregate used for the present studies are 20mm & downsize, 10mm & down size, and 6.3mm & downsize crushed stones. They are blended to achieve combined gradation. The physical properties of these aggregates are shown in the table-3, 4and 5 Table 3 Physical properties of coarse aggregates (20mm and down size) IS Sieve Size (mm)

Weight retained (gm)

Percentage Weight retained

Cumulative percentage weight retained

40

-

-

-

20

200

4

4

10

2950

59

63

4.75

1385

27.7

90.7

2.36

465

9.3

100

Pan

-

-

-

Total (Excluding pan)

257.7

F.M = (Total + 400)/100

6.577

Specific gravity

2.65

Unit weight Kg/m3

1564

Aggregate crushing value (%)

18.4

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High Volume High Performance Fly Ash Concrete Mix Design for Pavement Overlays for Sustainable Development Table 4 Physical properties of coarse aggregate (10mm and down size) IS Sieve size (mm)

Weight retained (gm)

Percentage Weight retained

Cumulative percentage weight retained

12.5

-

-

-

10

1058.1

35.27

35.27

4.75

1786

59.53

94.80

2.36

135

4.50

99.30

1.18

15.5

0.52

99.82

Pan

5.4

0.18

100

Total (Excluding pan)

329.19

FM = (Total + 300)/100

6.29

Specific gravity

2.68

Unit weight Kg/m3

1608

Aggregate crushing value (%)

21.1

Table 5 Physical properties of 6.3mm and down size IS Sieve size in (mm)

Weight retained (gm)

Percentage weight retained

Cumulative percentage weight retained

6.30

-

-

-

4.75

120

4.00

4.00

2.36

400.50

13.25

17.35

1.18

1056

35.20

52.55

0.6

565.5

18.85

71.40

0.3

390

13.00

0.15

339

11.30

95.70

Pan

129

4.3

100

84.40

Total (Excluding pan)

325.4

FM

3.254

Specific gravity

2.67 3

Unit weight Kg/m

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B. H. Manjunath, Dr. A. V. Pradeepkumar and Rahulraj. M Table 6 Combined gradation of 20mm, 12.5mm and 6.3mm aggregates. sieve Size (mm)

%Passig (20mm)

%Passing (10mm)

%passing (6.3mm)

Combined gradation (35% + 60% +5%)

40 20 12.5 10 4.75 2.36 1.18 600µ 300µ 150µ

100 96 37 9.3 0.8 -

100 100 100 64.73 5.20 0.70 0.18 -

100 100 100 100 96 82.65 47.45 28.60 15.6 4.30

100 98.60 70.00 59.94 15.51 8.92 4.85 2.86 1.56 0.43

3.4. Water Tap water is used for mixing and curing

3.5. Superplastisiser In the present studies, CONPLAST SP 430 is used as superplastisiser for maintaining workability, which complies with IS 9103-1979.It is based on Sulphonated Naphthalene polymer available in Brown liquid, instantly dispersible in water. Specific gravity is 1.18 at 22°_+ 2° and 1.220 to 1.225 at 30° C. For the present investigation specific gravity considered is 1.220

3.6. Flyash Flyash is used as the mineral admixture. ASTM C618 specifies two categories of flyash depending upon ‘Cao’content [8].The ‘Cao’content in the Class C flyash is more than 10%, which possess cementicious properties in addition to pozzolanic properties. This type of flyash is also known as calcareous flyash or high calcium flyash. Concrete made with this type of flyash has higher early strength because it contains its own lime and allows pozzolanic activity to begin earlier. At later stages, it behaves like class-F flyash. It consists primarily of calcium alumino-sulphate glass. The ‘Cao’ content in the Class F flyash is less than or equal to 10% and possess only pozzolonic properties. This type of flyash is also known as siliceous flyash or low calcium flyash. It consists of primarily alumino-silicate glass. For the present study Nayveli flyash is used. According to ASTM C618, this flyash belongs to Class C category, as its ‘Cao’ content is 13.8%.The physical and chemical properties of this flyash satisfies both parts of IS: 3812-2013, presented in the Table-6 and 7.

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High Volume High Performance Fly Ash Concrete Mix Design for Pavement Overlays for Sustainable Development Table 6 Chemical properties of flyash Requirements as per IS:3812:2013 Property of flyash

Sio2+Al203+ Fe2o3 (min) Sio2,percent by mass (min) Mgo percent by mass(max) Sio3 percent by mass(max) Loss on ignition percent by mass(max) Cao (%)

Result

Part-1

Part-2

Siliceous PFA

Calcareous PFA

Siliceous PFA

Calcareous PFA

83.70

70

50

70

50

45.62

35

25

35

25

1.80

5

5

5

5

3.79

3

3

5

5

3.57

5

5

7

7

13.8 Table 7 Physical properties of flyash

Characteristics Fineness- Specific surface in m2/kg by Blaine’s permeability method, (Min.) Particles retained on 45 micron IS sieve (Wet sieving) in percent, (Max.) Lime reactivity – Average compressive strength N/mm2,(Min.) Compressive strength at 28 days in N/mm2,(Min.) Soundness by autoclave test Expansion of specimen in percent, (Max.) Specific gravity

Results

Requirements for Siliceous flyash and Calcareous fly ash

329

320

26

34

5.4

4.5

88

˃ 80 percent of the strength of corresponding plain cement mortar cubes

0.031

0.8

2.43

-

3.7. Experimental Methodology The methodology involves Optimisation of superplastisiser for control concrete and fly ash concrete, and design of control concrete, and flyash concrete. 3.7.1. Optimisation of Superplastisiser Marsh cone test was used by researchers to evaluate the characteristics of different cement pastes, and to optimize the admixture. The Marsh cone test is made to know fluidity of cements with super plasticizers. Some super plasticizers may show higher fluidizing effect on same type of cement than other cement. The Marsh cone test was used to optimize the dosage of superplastisiser. For a given water-cement ratio, the Marsh cone flow time decreases for an increase in the dosage of superplastisiser until the “saturation point” is achieved [9].By increasing the dosage of superplastisiser beyond this point, the flow time is not modified significantly. Then this dosage of admixture indicates an optimum dosage or an effective limit for the superplastisiser where the maximum dispersion of cement particles is achieved. In the present study, 8mm http://www.iaeme.com/IJCIET/index.asp

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diameter orifice Marsh cone was used. Figure 1 and 2 shows Marsh cone and nature of graph. ASTM guide lines were followed.Table-8 gives the optimum values of superplastiser for control concrete and flyash concrete at different percentage of flyash.

Figure 1 Nature of graphs

Figure 2 Marsh cone

Table 8 Results of Marsh cone test Sl. No

Concrete

Time of flow (sec)

Optimum dosage of Superplastisiser (percentage)

1

Control Concrete

16.6

0.8

2

For 10% Fly ash concrete

17.8

0.9

3

For 20% Fly ash Concrete

18.2

1.0

4

For 30% Fly ash Concrete

19.4

1.1

5

For 40% Fly ash Concrete

20.2

1.2
...