1je00025_1375910324.pdf

ISSN: 2320-7213

Abhijeet A. Ulagadde PG Student, Department of Civil Engineering, Rajarambapu Institute of Technology, Rajaramnagar, Islampur, Dist. Sangli, Maharashtra, India

E-mail: [email protected]

WORLD JOURNAL OF ENGINEERING SCIENCE (Available online at http://www.wjesonline.com)

Development of M60 grade Self Compacting Concrete using Mineral Admixture in

Quaternary Blends

Abhijeet A. Ulagadde*1, Dr. P. D. Kumbhar2

1PG Student, Department of Civil Engineering, Rajarambapu Institute of Technology,

Rajaramnagar, Islampur, Dist. Sangli, Maharashtra, India

2Research Professor , Department of Civil Engineering, Rajarambapu Institute of

Technology, Rajaramnagar, Islampur, Dist. Sangli, Maharashtra, India

Received: 16 July 2013/ Accepted: 30 July 2013/ Published online: 08 Aug 2013 © WJES – 2013

ABSTRACT

: SCC is a highly flowable concrete which is able to fill the formwork and the areas of

congested reinforcement completely under its own weight and without the need for

vibration. It has slowly spread all over the world, showing many other characteristics.

However, for economical production of SCC, several researchers have recommended to

use different blends of mineral admixtures such as fly ash (FA), silica fume (SF), ground

granulated blast furnace slag (GGBFS), metkaolin (MK) etc. Also, there are no Standard

mix design procedures available for designing SCC mixes. Therefore, in the present

experimental work, SCC of M60 grade is tried to be developed by using Nan Su method

of mix design and by incorporating different mineral admixtures of FA, SF and GGBFS

with appropriate dosage of superplasticizers (SP) at different replacement levels of FA

and GGBFS at 15%, 20% and 25% and SF at 5%, 10% and 15% (by weight of

cement) in the form of quaternary blends to study workability and 28 days compressive

strength properties. 45% of total replacement (i.e. FA15%, SF15% & GGBFS15%) gave

good results for both fresh and hardened properties.

Keywords: Self Compacting Concrete, mineral admixtures, quaternary blends,

workability, Compressive strength.

1. INTRODUCTION:

SCC is basically a concrete which is capable of flowing into the form work, without

segregation, to fill uniformly and completely every corner of it by its own weight without any

application of vibration or other energy during placing. SCC was first introduced in the late

1980’s by Japanese researchers named Okamura. The main drive for the development of SCC

and its research were the endangered durability of reinforced concrete structures, need for

easier and high-quality fresh concrete placement and lack of skilled labour force [2].

However, the cost of production of SCC is higher, compared to conventional concrete, on

account of use of chemical admixtures and cement in large quantities [4]. For SCC, it is

generally necessary to use superplasticizers in order to obtain high mobility. Adding a large

volume of powdered material or viscosity modifying admixture can eliminate segregation.

The powdered materials that can be added are fly ash, silica fume, lime stone powder, glass

filler quartzite filler and GGBFS. Limestone filler will also help to control the heat of

hydration in mixes that have a high PC content [13].

RESEARCH ARTICLE

http://www.wjesonline.com/

Abhijeet A. Ulagadde. et al., W J Engg Sci, 2013; 1(4): 64-75

65

In the present work the initial mix proportion is determined by Nan-Su et al method of

mix design because there are no Standard mix design of SCC mixes, and fine tuned by using

different guidelines to get the mix which satisfies the required fresh and hardened properties

of SCC.

1.1 Properties of SCC:

i) Fresh SCC Properties:

The three main properties of SCC in plastic state are

a) Filling ability (excellent deformability)

b) Passing ability (ability to pass reinforcement without blocking)

c) High resistance to segregation.

a) Filling ability: Self compacting concrete must be able to flow into all the spaces within the formwork

under its own weight. This is related to workability, as measured by slump flow test. The

filling ability or flowability is the property that characterizes the ability of the SCC of

flowing into formwork and filling all space under its own weight, guaranteeing total covering

of the reinforcement. The mechanisms that govern this property are high fluidity and

cohesion of the mixture.

b) Passing ability:

Self compacting concrete must flow through tight openings such as spaces between

steel reinforcing bars under its own weight. The mix must not 'block' during placement.

The passing ability is the property that characterizes the ability of the SCC to pass

between obstacles gaps between reinforcement, holes and narrow sections, without blocking.

The mechanisms that govern this property are moderate viscosity of the paste and mortar and

the properties of the aggregates, principally, maximum size of the coarse aggregate. Stability

or resistance to the segregation is the properly that characterizes the ability of the SCC to

avoid the segregation of its components, such as the coarse aggregates. Such a property

provides uniformity of the mixture during transport, placement and consolidation. The

mechanisms that govern this properly are the viscosity and cohesion of the mixture.

c) High Resistance to Segregation

Self-compacting concrete must meet the requirements of passing ability and resistance

to segregation. Its original composition remains uniform. The key properties must be

maintained at adequate levels for the required period of lime (e.g. 20 min) after completion of

mixing. It is property passing ability and property resistance to segregation that constitute the

major advance, form a merely superplasticizer fresh mix which may be more fluid than self

compacting concrete mix.

Latest developments in accordance with the objectives of the European SCC project

aim to limit the admixtures used for general purpose SCC to only one by using new types and

combinations of polymers. Experience has shown that such an admixture may have to add to

generate and maintain compacting concrete using less liable materials.

(ii) Hardened Properties of SCC:

Self compacting concrete and traditional vibrated concrete of similar compressive

strength have comparable properties and if there are differences, these are usually covered by

the safe assumptions on which the design codes are based. However, SCC composition does

differ from that of traditional concrete as they are mixed in different proportions and the

addition of special admixtures to meet the project specifications for SCC. Durability, the

capability of a concrete structure to withstand environmental aggressive situations during its

design working life without impairing the required performance, is usually taken into account


66

by environmental classes. This leads to limiting values of concrete composition and

minimum concrete covers to reinforcement.

2. Mix Design of M60 grade SCC:

There is no standard method for mix design of SCC. Many academic institutions,

admixture, ready-mixed, precast and contracting companies have developed their own mix

proportioning methods. Different mix design methods available for getting the trial mixes of

SCC are:

1. The Japanese Method.

2. Sedran et al Method.

3. Method proposed by Gomes, Ravindra Gettu et al.

4. Nan-Su et al Method.

5. Method proposed by Jagadish Vengala.

6. European practice and specifications.

All these methods are developed based on the guidelines given by the EFNARC. The

mix composition is chosen to satisfy all specifications given by EFNARC for the concrete in

both the fresh and hardened states. Of the above listed methods, mix design of SCC using

Nan Su methods has been reported to be the simple method and hence is used for designing

SCC mix of M60 grade in the present study. This method is developed in Taiwan by Nan Su.

The step by step procedure of Nan Su method [22] for designing the SCC mixes is given as

below:

2.1 Mix Design of M60 grade SCC by Nan Su Method [22]

Aggregate size =12.5mm

Sp. gravity of coarse Aggregate =2.96

Bulk density of loose coarse aggregate = 1309.62 kg/m3

Sp. gravity of fine aggregate = 2.66

Bulk density of loose fine aggregate = 1040.8 kg/m3

Sp. gravity of cement = 3.15

Volume ratio of fine aggregate = 54%

Volume ratio of coarse aggregate = 46%

Sp. gravity of SP = 1.09

Air content in SCC = 2%

Design strength of SCC = 68.25 N/mm2

Step (1) Determine the coarse and fine aggregate content:

Ws = PF X WsL X

Where Ws= Content of fine aggregate in SCC (kg/m3).

PF= Packing factor.

WsL= unit volume mass of loosely piled saturated fine aggregate in air (kg/m3).

S/a= Volume ratio of fine aggregate to total which ranges from 50% to 57%.

Ws = 1.2 X 1040.8 X 0.54

= 674.43kg/m3

Amount of coarse aggregate needed per unit volume of SCC:

Wg = PF X WgL (1- S/a).

WgL = unit volume mass of loosely piled saturated surface dry coarse aggregate in air

(kg/m3).

Wg = Content of coarse aggregate in SCC (kg/m3).

= 1.2 X 1309.62 X (1- 0.54)

= 722.91 kg/m3


67

Step (2) Determination of cement content:

Assume each kg of cement can provide a compressive strength of 20 Psi (0.14 Mpa)

Amount of cement needed per unit volume of SCC.

C =

C= cement content (kg/m3)

fˈc= Designed compressive strength

C =

= 494.91 kg/m3

Step (3) Determine the mixing water content require by cement:

Wwc = (W/C) X C

Wwc = Content of mixing water content required by cement (kg/m3).

(W/C) = The w/c ratio by weight which can be determined by compressive strength.

Wwc = 0.30 X 494.91

= 148.47 kg/m3

Step (4) Determination of SP dosage:

The solid content of SP is 21%. According to previous engineering experience, the dosage of

SP is 1% of the content of binder i.e cement of meeting the SCC requirement specified in

table 1. Dosage of SP:

Wsp = 0.01 X 494.91

= 4.95 kg/m3

Step (5) Adjustment of mixing water content needed in SCC:

Amount of water in SP:

WwSP : (1- 0.21) X 4.95 = 3.91 kg/m3

Amount of mixing water needed in SCC

W = Wwc + Wwf + WwB – WwSP

= 148.47 + 0 + 0 – 3.91

= 144.56 kg/m3

Step (6) Estimated quantities of material per cubic meter of concrete are:

(1) Cement = 494.91 kg/m3

(2) Fine aggregate = 674.43 kg/m3

(3) Coarse aggregate = 722.91 kg/m3

(4) SP = 4.95 kg/m3

(5) Water = 144.56 kg/m3

Table no 2.1 Mix proportions

Cement Fine aggregate Coarse aggregate SP Water

1 1.39 1.49 0.10 0.292

2.2 Trial Mix


68

A trial mix was prepared by using the mix proportions (1: 1.39: 1.49: 0.10: 0.292)

obtained by following guidelines by Nan su method without incorporating any mineral

admixture (i.e. Control mix). So as to get satisfactory workability properties such as filling

ability and passing ability. However the prepared mix using the w/c (0.292) ratio as obtained

in the mix design process did not gave satisfactory workability. Hence a little modification

for w/c ratio was applied and a final w/c ratio of 0.3 was adopted for developing a control

mix which satisfies all the workability tests. Thus, the trial mixes of M60 grade SCC were

prepared by incorporating various mineral admixtures in quaternary blends by adopting a

final mix ratio of 1: 1.39: 1.49: 0.10: 0.3.

Table no 2.2 Trial mix for SCC

Sr. No. Mix ratio Slump flow SP L - Box V – funnel Remarks

1 1: 1.39: 1.49: 0.292 630 1.00% 0.80 13 Not satisfied

2 1:1.39:1.49:0.3 690 1.00% 0.93 10 SATISFIED

Table shows the trial mixes and its workability properties using mix ratio as obtained by mix

design process and adopting modified mix ratio.

3. Results:

3.1 General:

The SCC of M60 grade was designed using Nan-Su method and mix proportions were

obtained for development of SCC. The SCC specimen were prepared by adopting the mix

proportions so obtained and by replacing the cement content with different combinations of

mineral admixtures in quaternary blends. The SCC mixes were prepared by following the

standard procedure of mixing using Pan Type mixer and immediately after the delivery of

concrete the various workability tests were conducted. The specimens so cast were cured in

fresh water for 28 days curing period and then they were taken for determination of

compressive strength test. The results of the workability and compressive strength tests of

various SCC cube specimens of M60 grade have been discussed in the following sections.

3.2 Workability of SCC mixes:

After mixing was over, various workability tests namely Slump flow, V-funnel and L-

box were conducted immediately on the fresh SCC mix by Nan Su method procedures. The

details of these workability tests are presented in following sections.

Table 3.1 Workability values


69

Sr.No. Mix ratio Slump flow in mm V funnel flow

Time in (Sec)

L box

Test (H2/H1) Control mix 680 11 1.1

1

5%

15%

15% 670 11 0.876

20% 664 12 0.85

25% 660 11 0.88

2

5%

20%

15% 665 11 0.88

20% 665 12 0.89

25% 663 10 0.88

3

5%

25%

15% 672 9 0.90

20% 661 9 0.91

25% 665 8 0.90

4

10%

15%

15% 670 10 0.95

20% 668 8 0.95

25% 665 9 0.97

5

10%

20%

15% 675 8 0.98

20% 668 7 0.99

25% 670 7 1

6

10%

25%

15% 700 5 1

20% 690 6 1

25% 693 5 0.98

7

15%

15%

15% 720 5 1

20% 713 6 1

25% 707 5 1

15% 689 6 1


70

8 15% 20% 20% 691 6 0.99

25% 695 5 0.99

9

15%

25%

15% 680 5 1

20% 681 6 0.98

25% 677 6 1

3.2 Casting of SCC cube Specimens:

After proper mixing in machine mixer, the concrete was taken for workability test and

afterwards placed on rigid hard surface where the quality of concrete was observed and then

the concrete was poured in the cube moulds. The cube moulds of size 150mmx 150mm x

150mm were used for casting. For SCC tamping and vibration is not required. Before pouring

the concrete in moulds, the inner surfaces of moulds were coated with oil so they can be

easily demoulded after 24 hours. The top surface was levelled with trowel and finished

properly. The cube moulds were then placed on level surface for required setting of concrete.

Three cube specimens were cast for each variation of mineral admixture content. The

specimens were demoulded after period of 24 hours. The specimens were designated with a

specific identification number. The specimens were numbered according to their mineral

admixtures content followed by the specimen number from the three specimens considered

for casting.

Fig 3.1 Filling of moulds

3.3 Curing


71

After casting specimens are placed at room temperature covered with wet gunny bags

for 24 hr. then demoulded. After that they are transferred to curing tank with water at room

temperature for 28 days. The specimens are removed from the mould after 24 hrs. All the

specimens were kept in pure water tank for 28 days curing.

Fig 3.2 Curing of concrete cubes

3.4 Compressive Strengths of SCC Specimens:

The compressive strengths of M60 grade controlled SCC mix and mixes with

combined mineral admixtures in the form of quaternary blends have been presented in the

Table 3.2.

Table no.3.2 Compressive strength of SCC for different combinations of FA & GGBFS

at

constant SF

SF FA GGBFS Compressive Strength Average

strength

5

15

15

66.04

65.97 65.98

65.90

5

15

20

65.70

65.79 65.85

65.83

5

15

25

65.43

65.56 65.65

65.60

5

20

15

66.20

66.21 66.29

66.16

5

20

20

66.15

66.13 66.19

66.07

5

20

25

66.03

66.06 66.05


72

66.10

5

25

15

66.30

66.41 66.49

66.44

5

25

20

66.30

66.36 66.33

66.46

5

25

25

66.35

66.29 66.29

66.25

10

15

15

66.97

66.87 66.85

66.79

10

15

20

66.63

66.74 66.90

66.70

10

15

25

66.73

66.63 66.50

66.67

10

20

15

67.35

67.24 67.17

67.20

10

20

20

67.10

67.15 67.17

67.20

10

20

25

67.15

67.08 67.07

67.02

10

25

15

67.23

67.31 67.42

67.30

10

25

20

67.40

67.46 67.35

67.63

10

25

25

67.07

67.63 67.93

68.90

15

15

15

69.05

69.16 69.23

69.20

15

15

20

68.40

68.43 69.03

67.86

15

15

25

68.95

68.65 68.10


73

68.90

15

20

15

68.03

67.86

67.70

67.85

15

20

20

67.75

67.73 67.65

67.80

15

20

25

67.63

67.63 67.78

67.50

15

25

15

67.57

67.56 67.42

67.70

15

25

20

67.20

67.34 67.50

67.33

15

25

25

67.07

67.40 67.27

67.80

The variation in the compressive strength values and workability values of SCC mixes

have been expressed graphically for different replacement levels of combined mineral

admixtures in the form of quaternary blends and are shown in the Fig.3.4 to 3.7.

Fig. 3.4 Variation in Comp. St. for different % of GGBFS & FA at constant SF.

69.16

68.43 68.65

67.86 67.73 67.63

67.56 67.34 67.4

68.5 68.5

68.5

66

67

68

69

70

0 0.5 1 1.5 2 2.5 3

28 d

ays

com

p. st

. M

Pa

Percentage Variation in GGBFS

SF 15% + FA 15% SF 15% + FA 20%

SF 15% + FA 25% Control mix


74

Fig. 3.5: Variation in Workability (Slump) for different % of GGBFS & FA at constant

SF

Fig. 3.6: Variation in Time (V-funnel) for different % of GGBFS & FA at constant SF

Fig. 3.7: Variation in H2/H1 (L-box) for different % of GGBFS & FA at constant SF

It is observed that the workability as measured by all the methods namely slump flow,

V-funnel and L-box are found to be better for all the SCC mixes which have been prepared

720 713

707

689 691 695

680 681 677 680 680 680

670

680

690

700

710

720

730

10 15 20 25 30

Slu

mp

in

mm

Percentage variation in GGBFS

SF 15% + FA 15% SF 15% + FA 20% SF 15% + FA 25% Control mix

6 5

6 6

5

6

11 11 11

4

6

8

10

12

10 15 20 25 30

Tim

e in

sec

.

Percentage variation in GGBFS SF 15% + FA 15% SF 15% + FA 20% SF 15% + FA 25% Control mix

1 1

1 0.99

0.99

1

0.98

1

1.1 1.1 1.1

0.96

1.01

1.06

1.11

10 15 20 25 30 Rati

o o

f H

2/H

1

Percentage variation in GGBFS

SF 15% + FA 15% SF 15% + FA 20%

SF 15% + FA 25% Control mix


75

by incorporating mineral admixtures at replacement level of 45% (i.e. SF-15%, FA-15% and

GGBFS-15%) using a w/c ratio of 0.30 and SP dosage at 1% (by weight of cement). Also, all

the values are well within the limits given by EFNARC specifications.

4. Conclusion: The experimental work was carried out to develop M60 grade SCC and to study its

workability and strength properties by incorporating various mineral admixtures in

quaternary blends along with usual ingredients. From the experimental study so far carried

out, following conclusions can be drawn:

1. Development of M60 grade SCC is possible by following the guidelines of Nan Su

method of mix design and by incorporating mineral admixtures in quaternary blends (i.e.

OPC+FA+SF+GGBFS). As there is limited literature available on the development of

M50 and above grades of SCCs using Nan Su method of mix design, it can be now

recommended that the use of Nan Su method can satisfactorily be made for designing

M60 grade SCC by incorporating a specific combination of mineral admixture in the

form of quaternary blends.

2. The workability properties determined by the tests namely slump flow, V funnel and L

Box for all the mixes prepared by varying the replacement levels of quaternary blends

have been found to be within the specified range of EFNARC. However, the mix

prepared by incorporating a quaternary blends of FA, GGBFS and SF at 15% each (i.e.

45% cement replacement) have indicated better workability results.

3. The developed M60 grade SCC satisfies all the workability specifications, but the 28

days compressive strength requirement (68.25MPa) of the mix is found to be just

satisfied (69.15MPa) for a specific combination of quaternary blend of mineral

admixtures namely FA, GGBFS and SF at 15% each (i.e.FA-15%+GGBFS-15% +SF-

15%) thus replacing the cement content by 45% at a constant w/c ratio of 0.3 and at 1%

SP content by weight of cement. The 28 days compressive strength of the mix thus

obtained by incorporating quaternary blend is found to be slightly greater (1.31%) than

that of the control mix (68.50MPa) while all the other SCC mixes has shown

unsatisfactory strength results.

4. The variation in the results of the workability and 28 days compressive strength tests of

the developed M60 grade SCC goes well with the results published in the literature for

other lower grades of SCCs.

REFERENCES:

1. EFNARC, “The European Guidelines for Self Compacting Concrete Specification,

Production and Use”, May 2005.

2. Hardik Upadhyay, Pankaj Shah, Elizabeth George (2011) Testing and Mix Design Method

of Self-Compacting Concrete. National Conference on Recent Trends in Engineering &

Technology.

3. Nan Su, Kung-Chung Hsu, His-Wen Chai (2001) A simple mix design method for self-

compacting concrete. Cement and Concrete Research 31 (2001) 1799–1807.

4. Okamura H, Ozawa K (1995) Mix-design for self compacting concrete. Concrete JSCE

25:107–120.

5. W. Wongkeo, P. Thongsanitgarn, A. Chaipanich (2011) Compressive Strength of Binary

and Ternary Blended Cement Mortars Containing Fly Ash and Silica Fume Under

Autoclaved Curing, TICHE International Conference 2011 THAILAND.

1je00025_1375910324.pdf

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