Alccofine Tech Info

SYNOPSIS ALCCOFINE1203 performs in superior manner than all other mineral admixtures used in concrete within India. Due to its inbuilt CaO content, ALCCOFINE1203 triggers two way reactions during hydration •

•

Primary reaction of cement hydration.

Pozzolanic reaction: ALCCOFINE also consumes by product calcium hydroxide from the hydration of cement to form additional C-S-H gel, similar to pozzolans.

This results in denser pore structure and ultimately higher strength gain. This booklet presents results of examination carried out on ALCCOFINE1203 in comparison with Silica Fume in concrete, and the effect it has on workability, water requirement, admixture requirement, strength and durability. Thus, obtained results confirm that properly designed mixes with judicious use of ALCCOFINE 1203 exhibits superior properties than Silica Fume.

INTRODUCTION As a result of growth in advance technology in concrete, high performance concrete (HPC) has gained world wide popularity in the construction industry since 1990. In practice, high performance concrete, are generally characterized by high cement factors and very low w/cm ratios. Such concrete suffer from two major weaknesses. It is extremely difficult to obtained proper workability, and to retain the workability for sufficiently long period of time with such concrete mixes. High dosage of high range water reducing agents(HRWR) then become a necessity, and resulting cohesive and thixotropic, sticky mixes are equally difficult to place and compact fully and efficiently. These problem indicate that there is probably a critical limit for the water content below which high HRWR dosage become not only essential but also unhelpful and undesirable, and often even harmful from a durability point of view. In high performance concrete applications, Silica Fume is generally proposed as the appropriate cement extender where high strength, low permeability are the prime requirements. Though silica fume is known to improve durability, its addition in concrete is often negated by the increase water and/or admixture dosage required to improve the workability and handling properties of the fresh concrete. ALCCOFINE 1203 is a specially processed product based on slag of high glass content with high reactivity obtained through the process of controlled granulation. The raw materials are composed primary of low calcium silicates. The processing with other select ingredients results in controlled particle size distribution (PSD). The computed blain value based on PSD is around 12000cm 2/gm and is truly ultra fine. Due to its unique chemistry and ultra fine particle size, ALCCOFINE1203 provides reduced water demand for a given workability, even up to 70% replacement level as per requirement

COUNTO MICROFINE PRODUCTS PVT. LTD. CORPORATE CORPORATE OFFICE: OFFICE: Sukerkar Mansi on, Fir st Flo or, M.G. Road, Panjim, Go a - 403001 (INDIA), (INDIA), MUMBAI MARKETING OFFICE Abinash Mishra, General Manager Marketing, Marketing, Ambuja Ceme Cements nts L imited National Sales and Marketing Head- ALCCOFINE ALCCOFINE Rang, Cell : +91989 +919892370453 2370453,, 022-40667260(D 022-40667260(Direct) irect) C/o- Ambuja Cements Cements Lim ited Elegant Business, 2nd Floor, Behind Ko tak Mahindra Bank, Off Andheri Kurla Road, Andheri East, Mumbai-59

of concrete performance. ALCCOFINE 1203 can also be used as a high range water reducer to improve compressive strength or as a super workability aid to improve flow.

CHARACTERISTICS AND PROPERTIES As can be seen in the chemical composition and physical characteristics listed in Table 1, ALCCOFINE 1203 has got the unique chemical composition mainly of CaO 31-33% and SiO2 33-35%. Physically the product is unique with regards to its particle size distribution. Figure: 1, demonstrates the comparative particle size distribution analysis. TABLE. 1 Distinctive chemical composition and physical composition Chemical Analysis CaO Al2O3 Fe2O3 SO3 MgO SiO2

Mass % 32-34 18-20 1.8-2 0.3-0.7 8-10 33-35

Range 600-700 kg/m3 12000 cm2/gm Irregular <2µ < 5µ <9µ

Physical analysis Bulk Density Surface Area Particle shape Particle Size, d 10 d50 d90

Figure. 1 Particle Size Distribution

PARTICLE SIZE D ISTRIBUTION

110 100 90 80 70

g n i s 60 s a P 50 % 40 30 20 10 0 0.1

0.5

1

5

10

18

25

45

65

75

Microns M ic ro S il ic a

A LCCO FINE 1203

OP C

CONCRETE QUALITY AND MIX DESIGN COUNTO MICROFINE PRODUCTS PVT. LTD. CORPORATE OFFICE: Sukerkar Mansi on, Fir st Flo or, M.G. Road, Panjim, Go a - 403001 (INDIA), MUMBAI MARKETING OFFICE Abinash Mishra, General Manager Marketing, Ambuja Cements L imited National Sales and Marketing Head- ALCCOFINE Rang, Cell : +919892370453, 022-40667260(Direct) C/o- Ambuja Cements Lim ited Elegant Business, 2nd Floor, Behind Ko tak Mahindra Bank, Off Andheri Kurla Road, Andheri East, Mumbai-59

The quality and impermeability of high performance concrete are, determined by the amount of water utilized in mix design i.e. the water/binder ratio. High range water reducers (HRWR) are extensively used to ensure placement with low water contents. The presence of extremely fine particles decreases the permeability and improves durability. In order to measure the effect of ALCCOFINE1203 on the workability, water requirement and HRWR dosages, three sequences of concrete mixes were prepared, based on the following mix design methodology: A. Workability: Maintaining the water/binder ratio, admixture dosage constant and measuring the slump and compressive strength. B. Water Demand: Maintaining the admixture quantity constant and varying the water/binder ratio and measuring the slump and compressive strength. C. Admixture Requirement: Maintaining the water/binder ratio constant and varying the admixture content and measuring slump and compressive strength.

In all three methodologies binders are OPC – 430 kg, Fly Ash – 80kg and alternately using ALCCOFINE1203 – 40kg and Silica Fume – 40kg as total binder content. The total binder content was maintained constant at 550kg/m3. Crushed Basalt rock was used as coarse aggregate and local river sand was used as fine aggregate. These materials used were dried completely before using. The HRWR used was Polycarboxylate ether.

EXPERIMENTAL PROGRAM Considering typical mix design, the further changes were carried out as per the described methodologies. TABLE.2 Typical Mix Design Mass of Constituents (kgs)

Materials

Reference Mix Silica Fume

Sample mix ALCCOFINE 1203

Cement

430

430

Fly Ash

80

80

Silica Fume

40

0

Alccofine1203

0

40

Water

160

160

Admixture

4

4

COUNTO MICROFINE PRODUCTS PVT. LTD. CORPORATE OFFICE: Sukerkar Mansi on, Fir st Flo or, M.G. Road, Panjim, Go a - 403001 (INDIA), MUMBAI MARKETING OFFICE Abinash Mishra, General Manager Marketing, Ambuja Cements L imited National Sales and Marketing Head- ALCCOFINE Rang, Cell : +919892370453, 022-40667260(Direct) C/o- Ambuja Cements Lim ited Elegant Business, 2nd Floor, Behind Ko tak Mahindra Bank, Off Andheri Kurla Road, Andheri East, Mumbai-59

TAblE.2 A : Materials Used For Experiment

Material

Brand Name

Product

Cement

ACC

43 Grade OPC

Fly Ash

Dirk (I) Pvt. Ltd.

P 60

Silica Fume

ORkLA (I) Pvt.Ltd. (Formerly known as Elkem India Pvt.Ltd.)

920 D

Admixture

Glenium BASF

B - 244

METHODOLOGY A: ASSESSMENT OF WORKABILITY From Table 3 and Figure 2 it is clear that replacement of part of binder by ALCCOFINE1203 improves the compressive strength as well as slump of the concrete subsequently, even by maintaining water/binder ratio and admixture dosage constant, in comparison with Silica Fume. Due to its unique particle size distribution and inbuilt CaO , ALCCOFINE1203 results in to formation of dense pore structure, which results in improved workability, workability retention and compressive strength at all ages.

TABLE 3.: Workability data for concrete specimens of equal water/binder ratio and containing same amount of HRWR Assessment of Workability

Materials



Cement

430

430

Fly Ash

80

80

Silica Fume

40

0

Alccofine1203

0

40

Water

160

160

Admixture

4

4

Note:- Contents in kg/m

3


FIGURE 2. ASSESSMENT OF WORKABILITY 250 200 m m150 n i

Reference Mix

p m100 u l S

Sample Mix

50 0 Initial

30 min

60 min

90 min

120 min

Period

The rates of strength development for 1, 3, 7, 28 and 56 days and workability of concrete with ALCCOFINE1203 in comparison with Silica Fume is stated in table 5.Which indicate ALCCOFINE1203 is batter than Silica Fume as per the tests carried out. TABLE 4.

The effect of ALCCOFINE1203 addition on compressive strength and workability of concrete specimen with equal water/binder ratio. SLUMP (mm) Reference mix Silica Fume


Initial

180

210

30 min

150

180

60 min

110

150

90 min 120 min

90 120 60 95 Compressive Strength (MPa)

1 Day

20.4

20.58

3 Day

38.29

45.11

7 Day

49.83

55.72

28 Day

64.17

67.44

56 Day

68.25

70.42


3


METHODOLOGY B: ASSESSMENT OF WATER DEMAND The quality feature of ALCCOFINE 1203 is the optimized particle size distribution and unique chemical composition, which reduces the water demand to achieve a specific slump value. In this methodology, the binder content and admixture content were kept constant and the outcome on water requirement, workability and compressive strength were measured. TABLE 5. The effect of ALCCOFINE 1203 on the water required to maintain a constant slump. Assessment of Water Requirement

Materials



Cement

430

430

Fly Ash

80

80

Silica Fume

40

0

Alccofine1203

0

40

Water

160

152

Admixture

4

4


3

FIGURE 3 ‘A’: ASSESSMENT OF WATER REQUIRED

Water

0

20

40

60

80

100

120

140

160

180

WaterDemand in liter s Reference Mix Micro Silica



FIGURE 3 ’B’: ASSEMENT OF WORKABILITY 250 200 m m150 n i p m100 u l S

Reference Mix Sample Mix

50 0 Initial

30 min

60 min

90 min

120 min

Period

It is clear from Table 6 and Figure 3-‘A’ and ‘B’ that decrease in water content increases the compressive strength. Coming to workability, though the water is decreased in sample mix of ALCCOFINE 1203, the retention of slump is better as compared to Silica Fume. The decrease in water demand is because of high glass content which has water repelling property. TABLE 6: Compressive strength and workability of concrete specimen with constant binder and HRWR content. SLUMP (mm) Reference mix Silica Fume


Initial

190

200

30 min

155

160

60 min

120

130

90 min 120 min

95 65

110 80

Compressive Strength (MPa) 1 Day

21.3

23.54

3 Day

38.75

47.2

7 Day

50.02

60.42

28 Day

64.50

70.47

56 Day

68.50

74.44


3


At a constant binder content, the compressive strength of concrete increased along with a reduction in water. As a result the assimilation of ALCCOFINE 1203 in concrete facilitates a lower water/binder ratio, which in turn achieves improved compressive strength at all ages and durability as well.

METHODOLOGY 3: ASSESSMENT OF HRWR REQUIREMENT Finer particle size results in rendering more surface area for pozzolanic reaction, allowing concrete achieving higher strength very easily. Due to optimized particle size of ALCCOFINE 1203 workable concrete can be made using less admixture content. For this Methodology water/binder ratio was kept constant and HRWR in case of ALCCOFINE 1203 was reduced, to check the workability and compressive strength. TABLE 7: Assessment of HRWR required fo r a concrete specimen at constant water/binder ratio. Assessment of HRWR Requirement

Materials



Cement

430

430

Fly Ash

80

80

Silica Fume

40

0

Alccofine1203

0

40

Water

160

160

Admixture

4

3.00


3

FIGURE 4 ‘A’: ASSESSMENT OF HRWR REQUIRED

Admixture

0

1

2

3

Admixture Dosage in kg

Reference Mix Micro Silica

4

5



FIGURE 4 ‘B’: ASSEMENT OF WORKABILITY

250 200 150 100 50 0 Initial

30 min

60 min

Referenc e mix Micro Silica

90 min

120 min


It is clear from Table 8 and Figure 4 -‘A’ and ‘B’ that even by reducing the content of HRWR ALCCOFINE 1203 shows better workability and compressive strength, as compared to Silica Fume. Using AlCCOFINE1203 in concrete specimen reduces the amount of HRWR as compared to Silica Fume which in turn reduces the mix cost. ALCCOFINE 1203 provides a lower HRWR dosage to obtain a desired workability. TABLE 8: Workability and compressive strength of concrete specimen at constant water/binder ratio.

SLUMP (mm) Reference mix Silica Fume


Initial

185

195

30 min

150

165

60 min

125

130

90 min 120 min

100 60

115 75

Compressive Strength (MPa) 1 Day

20

22.58

3 Day

38.95

46.12

7 Day

49.23

54.72

28 Day

63.57

68.64

56 Day

68.05

72.52



3

Concrete containing ALCCOFINE 1203 display superior results of compressive strength as compared to Silica Fume.

DISCUSSION OF MIX DESIGN CRITERIA AND THEIR TEST RESULTS The mix deigns containing ALCCOFINE 1203 are prepared to give optimum advantages in terms of technical as well as economical benefits. The obtained comparative results clearly confirm the superior performance of ALCCOFINE 1203 over Silica Fume. As per the methodologies carried out, in first case with equal amount of water/binder ratio and HRWR in concrete specimen the comparative results of ALCCOFINE 1203 is better than the silica fume. The results are similar even in other two methodologies. Increase in strength & workability and decreased HRWR ratio is mainly due to the optimized Particle Size Distribution and proper chemical composition of ALCCOFINE 1203. ALCCOFINE 1203 facilitate to reduce water content and/or HRWR dosage to provide superior performance of concrete in terms of workability and compressive strength over Silica Fume. long term pozzolanic activity of ALCCOFINE 1203 can be observed as a function of its particle size distribution and chemical composition. ALCCOFINE 1203 results in to formation of dense pore structure and inbuilt CaO provides increased secondary hydrated products because of which improved strength gain at early as well as later ages are observed. Secondary hydrated products formed due to pozzolanic and Cementitious hydration reaction fills the pores. This reduces the permeability of hydrated products to great extent and protects concrete from chemical attack.

DURABILITY Though the growing strength is an important criterion for concrete performance, it sometimes fails to give a desired durability. Under durability water permeability and chloride penetration were measured most commonly. Engineers are, by nature, fascinated and indeed obsessed, by high strength and very high strength concrete. Misconception is widely-held that high strength concretes are, per se, highly durable. The impetus for higher and higher concrete strengths also came from demands for exceptional increases in the height of high-rise buildings and for long span bridges. High strength concrete is often characterized by high cement factors and very low w/cm ratios. Such concretes generally suffer from two major weaknesses i.e. extremely difficult to obtain proper workability and to retain the


workability for a sufficiently long period of time. Thus concept of strength through durability become essential. (Ref. concept of strength through durability – R N Swamy – University of Sheffield, England) Permeability of concrete often dictates the performance with respect to durability. Chloride ion penetration is the most frequently specified durability criterion for a long term service life of concrete structures. RCPT ASTM C1202 is an Standard Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration.(Title of ASTM C1202-05) ASTM C1202 says that this test method is applicable to types of concrete where correlations have been established between this test procedure and long term chloride penetration by ponding method. (ASTM C1202 -05,clause1). Most importantly ALCCOFINE 1203 has ability to increase the service life of concrete by its ‘Packing Effect’. Packing effect retards ingression of aggressive agents in concrete even by diffusion and thus enhances durability of concrete. The concrete sample for durability test used was having same proportion as in sample ‘Methodology A’. To test ALCCOFINE 1203 for Chloride penetration we have used ASTM C 1543.

WATER PERMEABILITY The test used to measure the impermeability of concrete was DIN 1048. According to this test the cubes were initially water-cured for 28 days, and then exposed to water pressure of 5 bars for 72 hours after which the cube was divided and the depth of water penetration measured. Penetration of less than 25 mm is generally considered to be impermeable concrete. TABLE 9: Water Permeability (DIN 1048) Assessment of water permeability Reference Sample mix Mix Silica ALCCOFINE Materials Fume 1203 Cement

430

430

Fly Ash

80

80

Silica Fume

40

0

Alccofine1203

0

40

Water

160

160

Admixture

4

4

Water Permeability

18mm

13mm


3


As per the results described above we can see that the water permeability in case of ALCCOFINE 1203 is less than that of Silica Fume. Presence of ultra fine Cementitious / pozzolanic materials allows denser packing between cement particles and reduces the ‘wall effect’ in transition zone between the paste and the aggregate. This refines the concrete microstructure and enhances the degree of impermeability and the strength characteristics of concrete .

CHLORIDE PERMEABILITY The chloride penetration test was compared between ALCCOFINE 1203 and OPC. The ASTM C 1543 test measures the penetration of chloride iron into concrete. Three slabs of concrete measuring 90mm + 15mm thick and 300mm square surface area. The slabs used were water cured for 28 days. After the conditioning period 3% NaCl solution was ponded on a top surface for 90 days, while the bottom face was left exposed to drying environment. At the end of this time powdered samples by rotary impact hammer are obtained at various depths (10-20, 25-35, 40-50, 55-65mm). Chloride content of the sample from each depth were determined and reported.

TABLE 10 : Concrete mix design for chloride permeability test Concrete Mix Design Materials

Reference Mix


Cement

400

360

Alccofine1203

0

40

Water

160

160

Admixture

2

2


3

TABLE 11 : The ASTM C 1543 test / salt ponding test Results (% by mass)

Depth of Sample Extraction (mm)

Chloride content for OPC concrete Controlled Material

Chloride content with ALCCOFINE 1203

Top Surface

0.4

o.3900

5 mm depth

0.31

0.045


10 mm depth

0.29

0.0056

15 mm depth

0.2

0.0051

20 mm depth

0.18

0.0051

25 mm depth

0.15

0.0048

30 mm depth

0.15

0.0048

35 mm depth

0.11

0.0048


3

Because of its finer pore structure and chemical stability, ALCCOFINE 1203 in concrete is substantially more resistant to chloride diffusion. Thus, it reduces the penetration of chlorides in concrete and protects embedded steel from corrosion. CaO available in ALCCOFINE 1203 Contribute to maintain CaOH as buffer in pore Solution, which helps to maintain pH of pore solution. Denser pore matrix restricts chloride penetration and alkalinity forms passive layer on steel and protect it from corrosion.

TECHNICAL BENEFITS Till now we have conducted many trials, at various organization to assess the properties of ALCCOFINE 1203 and its performance in concrete. These trials results shown following benefits:  Fresh State Improves workability retention Improves flow ability Improves rheology Reduces segregation Reduces heat of hydration  Hardened state Improves durability Improves resistance to ASR Improves strength at all ages Improves resistance to chemical attack / corrosion Imparts light color Lowers permeability • • • • •

• • • • • •


APPLICATIONS The application of ALCCOFINE 1203 in various Cementitious materials are gives below: • • • • •

High rise Structure Marine Structure Ports Roads Bridges

SUMMARY ALCCOFINE 1203 can be used as practical substitute for Silica Fume as per the results obtained. If the advantages of ALCCOFINE 1203 are observed in the concrete mix design, the initial rate of strength development was found to be increased or similar as that of Silica Fume. Durability test measuring the water permeability showed better results than the Silica Fume. But in case of chloride permeability we have compared ALCCOFINE 1203 with OPC and the results shows less permeability incase of ALCCOFINE 1203 than that of OPC. The use of ALCCOFINE 1203, as an alternative to Silica Fume can be effective in enhancing the properties of concrete, both in its fresh and hardened state. Due to the lower water demand, ALCCOFINE 1203 can be ideally used to: • • •

Lower the water/binder ratio Use of more cost-effective admixture dosages A combination of above

ALCCOFINE 1203 is a new generation supplementary cementitious material (SCM) with a built-in high tech content. In spite of its high fineness it does not increase water demand at the dosage range of 5 to 15 percent of normal OPC in general. In fact concrete slump is seen to be improved, due to the dense packing of cementitious material, producing low void content. The use of ALCCOFINE 1203 results in hydrated cement matrix to comprise of very small pores. Strength development increases drastically at early ages and the later on strengths are higher compared to traditional supplementary cementitious material due to its unique PSD. Concretes of over 100 MPa (HPC / UHPC) are possible to be made using ALCCOFINE 1203. Judicious use of ALCCOFINE 1203 can produce concrete of superior properties and performance in every way


Alccofine Tech Info

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