Chapter 5: PHYSICAL AND CHEMICAL …shodhganga.inflibnet.ac.in/bitstream/10603/28408/12/12...61...

61

Chapter – 5: PHYSICAL AND CHEMICAL CONSTITUENTS OF

CEMENT AND THEIR RESPONSE

S.No Name of the sub-title Page No

5.1 Estimation of ‘1’ day Compressive Strength 65

5.1.1

Effect of physical and chemical

constituents on 1 day compressive

strength

65

5.1.2 Theoretical model for 1 day strength 70

5.1.3

Significance of single and multiple

constituents for 1 day strength 71

5.1.3.1

Significance of single constituent

interactions for 1 day strength 73

5.1.3.2

Significance of multiple constituent



5.2.1



strength

89


5.2.3



5.2.3.1



5.2.3.2



62


5.3.1



strength

115


5.3.3



5.3.3.1



5.3.3.2



5.4 Estimation of ‘28’ day Compressive

Strength 135

5.4.1



strength

135


5.4.3



5.4.3.1



5.4.3.2



5.5 Estimation of Physical parameters of

cement samples and their relevance to

quality

159

63

5.6 Correlations based on the experimental

data and JMP statistical analysis 163

5.7 Validation of specifications generated by

JMP statistical software and constituent

parameters

163

64

Chapter – 5

PHYSICAL AND CHEMICAL CONSTITUENTS OF CEMENT AND

THEIR RESPONSE

The objective of the present thesis is to analyze physical

constituents like <10, <30, and <53 µm particles, as well as chemical

constituents like LOI, IR and SO3, and compressive strength for 1,3,7

and 28 days of all the commercial cement samples (88 samples). The

generated data was subjected to statistical analysis using JMP

software. Significance of single constituent as well as interaction of

multiple constituents were found on the compressive strength.

Further, the physical parameters like bulk, tapped densities and

Husner’s ratio, and surface area were also estimated which in turn

depends on physical and chemical constituents of cement sample.

These values are correlated with JMP software output, to establish

ranges of constituents and parameters towards enriching quality of

cement, and were validated with fresh set of samples.

5.1. Estimation of 1 day compressive strength

5.1.1. Effect of physical and chemical constituents on 1 day

compressive strength

All the 88 cement samples were subjected to analyze for

physical and chemical constituents, and the results as well as

response in terms of compressive strength for 1 day is shown in the

Table 5.1. The data in the Table 5.1 shows that the particles of <10

65

µm are found to be in the range of 15.59 % to 36.79 %, and the

corresponding one day strength values are 9.75 MPa and 21.11 MPa,

which infers that one day strength is directly proportional to

percentage of <10 µm particles.

The particles of <30 µm are found to be in the range of 41.23 %

to 74.18 %, and the corresponding one day strength values are 9.75

MPa and 21.112 MPa, which infers that one day strength also is

directly proportional to percentage of <30 µm particles. However in

some samples one day strength found to be high even if the

percentage is approximately 65%, which may be because of other

enriched parameters like blaines and optimal chemical parameters.

The particles of <53 µm are found to be in the range of 74.12 %

to 91.36 %, and the corresponding one day strength values are 13

MPa and 14.32 MPa, which infers that < 53 µm particles will not have

direct effect for one day strength, however certain range is required in

maintaining quality. From the physical constituents of <10, <30 and

<53 higher percentage of finer values are favoring one day strength, in

line with established research [12].

The values of Loss on Ignition (LOI), SO3, IR, are found to be in

the range as specified by BIS [116]. LOI values are observed to be in

the range of 1 to 4.1, the values of SO3 are observed to be in the range

of 1.1 to 2.95, and the values of IR are observed to be in the range of

13.9 to 38.9.

One day strength at minimum LOI found to be 10.55, which is a

moderately a good strength, whereas at maximum LOI the strength

66

found to be 11.36, which is also moderately a good value. With the

values of LOI it can be inferred that the values has no direct influence

towards strength development, the strength depends on other

constituents, however in whole set of samples it had been observed

that higher LOI values are yielding lesser one day strengths, in some

of the cases LOI values are compensated with other constituents like

<10, <30, and <53, which are associated with other physical

parameters like bulk density, tapped density, Husner’s ratio and

surface area.

One day strength at minimum SO3 value found to be 18.25,

which is a very good strength, whereas at maximum SO3 value the

strength found to be 10.74, which is moderately a feeble value. With

the values of SO3 it can be inferred that lesser SO3 values are yielding

higher one day strength, however irrespective of the SO3 values in

some samples the strength found to be invariable, this could be due to

the interference of other constituents like <10 µm, <30 µm, and <53

µm, which are associated with physical parameters.

One day strength at minimum IR value found to be 16.44,

which is a moderate strength, whereas at maximum IR value the

strength found to be 20.6, which is a very good strength. The general

trend shows that, as the percentage of IR increases the strength is

decreasing, however for some samples, though the IR value is more

strength is also found to be more, this may be because of perfect

combination of constituents like <10, <30, and <53, which are

associated with other physical parameters

67

Table 5.1: Experimental Results of ‘1’ day compressive strength of

cement samples with respect to physical and chemical constituents

S.No LOI

(%)

SO3

(%) IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles

1 day Strength

(MPa)

1 2.0 1.21 32.6 19.87 49.21 74.52 06.58

2 1.0 1.84 28.7 33.10 69.31 88.46 13.80

3 1.0 2.84 28.6 27.79 62.15 84.49 08.43

4 2.0 1.51 28.8 33.96 70.73 89.24 14.61

5 1.0 1.68 19.8 36.14 73.32 91.36 14.31

6 1.9 2.31 19.1 34.53 71.52 89.62 11.16

7 1.0 2.03 19.7 26.60 66.81 85.22 10.35

8 1.8 1.90 31.0 23.18 54.96 79.42 12.89

9 2.4 1.82 26.1 20.80 51.10 76.36 11.77

10 1.0 1.74 25.1 24.17 56.63 76.72 10.55

11 2.5 2.06 16.6 22.74 54.35 79.00 23.40

12 3.3 2.02 21.4 27.33 61.91 84.50 11.77

13 1.9 1.92 27.0 36.79 74.18 90.70 21.11

14 2.6 2.64 23.7 27.50 71.99 85.50 14.61

15 1.3 1.27 26.5 33.54 74.08 90.73 16.44

16 2.8 1.13 19.8 34.34 72.99 90.38 11.77

17 2.0 2.09 20.4 33.58 73.10 90.37 8.90

18 3.3 1.96 24.7 22.21 53.85 78.83 10.50

19 2.2 1.51 22.1 25.34 66.64 82.20 07.50

20 2.0 1.75 36.7 27.40 61.94 84.52 14.50

21 2.7 1.65 25.1 29.01 64.50 86.15 10.30

22 2.1 1.65 19.1 29.19 64.59 86.14 16.44

23 2.2 1.30 23.0 28.08 63.15 85.35 14.90

24 2.8 1.81 22.1 22.47 53.86 78.55 8.83

25 1.5 1.26 21.5 25.14 63.71 85.98 16.64

26 2.6 2.43 23.9 28.24 62.80 84.90 8.45

27 2.3 2.36 21.8 26.14 66.94 86.43 16.44

28 2.3 2.81 27.4 30.55 66.18 86.91 12.99

29 2.0 1.47 36.0 31.10 66.91 87.31 11.00

30 1.9 2.09 29.7 26.87 60.81 83.67 07.80

31 2.3 2.70 24.9 22.94 54.47 78.97 11.00

32 1.8 2.50 13.9 31.00 72.38 89.14 16.44

33 2.9 2.80 27.5 27.01 63.91 83.66 14.31

34 1.7 2.10 27.5 34.03 70.76 89.24 17.66

35 2.0 2.40 15.5 25.19 58.34 78.01 17.66

36 2.4 2.22 23.5 28.14 69.94 84.43 17.25

37 2.0 2.0 29.3 33.88 70.23 89.08 14.50

38 2.2 2.30 30.6 30.77 66.29 86.90 14.50

39 2.4 1.10 30.4 29.12 64.11 85.71 18.25

40 1.6 1.79 27.0 26.87 63.40 81.12 09.65

41 1.0 2.95 33.5 29.25 64.18 85.70 10.74

42 2.0 1.99 23.8 30.05 65.48 86.52 10.41

43 2.0 1.34 27.0 29.11 64.11 85.71 14.61

44 4.1 2.15 18.2 31.54 67.12 87.29 11.36

68

S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles

1 day Strength

(MPa)

45 3.2 1.57 38.9 32.93 69.23 88.47 20.6

46 1.4 2.90 31.3 34.13 70.85 89.23 13.9

47 1.5 1.78 31.5 31.74 67.60 87.69 09.65

48 2.5 2.02 34.5 36.14 73.32 91.30 11.46

49 2.3 1.82 34.9 31.16 66.94 87.30 18.25

50 3.0 0.45 21.5 28.79 63.52 85.30 17.25

51 3.0 2.98 19.6 32.36 68.47 88.00 17.15

52 2.9 1.99 23.3 22.88 54.43 78.90 08.83

53 1.2 2.06 23.0 25.20 63.74 84.78 14.91

54 3.0 1.92 36.1 22.50 53.85 78.55 12.17

55 2.2 2.92 23.1 22.64 53.88 78.53 11.77

56 1.5 2.54 30.6 34.21 70.84 89.33 15.52

57 1.5 1.78 18.2 25.97 63.55 82.66 17.05

58 2.5 1.90 33.0 33.44 66.55 86.09 11.46

59 2.3 2.70 24.4 24.59 57.30 78.14 09.33

60 2.2 1.50 19.0 25.75 59.04 82.15 10.19

61 2.2 1.90 26.9 29.49 64.74 86.10 16.0

62 3.0 2.30 20.1 26.62 60.30 83.20 16.54

63 2.9 2.0 24.0 21.08 51.62 76.80 07.74

64 1.7 2.0 28.0 22.13 53.28 78.12 07.66

65 1.5 1.50 20.6 20.82 51.12 76.35 10.83

66 2.4 1.90 24.8 22.71 54.33 79.00 10.18

67 1.8 2.50 22.50 21.26 51.73 76.70 09.87

68 2.3 1.80 31.9 24.23 56.67 80.70 10.59

69 2.7 2.70 27.0 30.75 66.28 86.90 10.26

70 2.0 2.30 31.5 29.32 64.22 85.70 15.63

71 1.4 1.50 19.7 21.55 57.60 77.70 16.13

72 2.1 2.00 18.1 27.75 62.13 84.40 16.44

73 3.0 2.30 23.0 26.38 60.17 83.20 09.98

74 2.3 1.60 24.4 36.14 73.32 91.30 08.80

75 2.3 2.0 30.9 23.89 56.10 80.28 08.8

76 1.2 2.10 25.1 25.97 59.55 76.80 10.55

77 2.0 2.69 22.7 26.76 65.78 83.00 08.52

78 2.3 1.65 27.0 26.42 57.14 84.40 08.43

79 3.0 2.0 21.7 27.76 62.13 84.40 10.86

80 2.4 1.84 23.4 25.70 51.04 76.37 08.45

81 2.4 2.11 15.0 20.80 51.11 76.37 17.66

82 2.5 2.0 15.5 26.42 63.52 81.60 23.43

83 2.5 2.12 27.5 25.77 64.72 84.70 19.00

84 1.9 1.84 31.3 19.28 48.51 74.12 13.29

85 3.2 2.1 22.1 15.59 41.23 66.60 09.75

86 2.1 2.5 24.6 19.84 49.51 75.02 09.51

87 1.8 2.0 19.5 22.89 54.79 79.00 10.11

88 2.4 2.0 23.4 19.88 49.54 75.00 10.17

Using the data reported in Table 5.1, statistical analysis of effect of

individual constituent on one day compressive strength as well as

69

combined effect has been studied using JMP statistical software. An

equation is developed for one day compressive strength as a function

of physical (<10, <30, and <53 micron particles) and chemical

constituents (Loss On Ignition, Insoluble Residue and Sulfuric

anhydride)

5.1.2. Theoretical model/equation for ‘1’ day strength:

106.6-4.3*LOI+-6.0*SO3+0.6*IR+-1.8*L10+3.0*L30+(-2.5*L53)+[-12.1

*(LOI-2.1)]*(LOI-2.1)+7.5*(LOI-2.1)*(SO3-2.0) +[-0.04*(LOI-2.1)

*(IR-24.6)]+-5.5*(LOI-2.1)*(L10-30.7)+1.9*(LOI-2.1)*(L30-65.8)+2.0

*(LOI-2.1)*(L53-88.7)+0.26*(SO3-2.0)*(SO3-2.0)+1.2*(SO3-2.0)

*(IR-24.6)+1.7*(SO3-2.0)*(L10-30.7)+-5.6*(SO3-2.0)*(L30-65.8)+6.4

*(SO3-2.0)*(L53-88.7)+0.05*(IR-24.6)*(IR-24.6)+-0.42*(IR-24.6)

*(L10-30.7)+0.31*(IR-24.6)*(L30-65.8)+0.07*(IR-24.6)*(L53-88.7)+1.6

*(L10-30.7)*(L10-30.7)+1.1*(L10-30.7)*(L30-65.8)+-4.9*(L10-30.7)

*(L53-88.7)+-0.8*(L30-65.8)*(L30-65.8)+1.6*(L30-65.8)*(L53-88.7)+1.0

*(L53-88.7)*(L53-88.7)+[-1.6*(LOI-2.1)*(LOI-2.1)*(LOI-2.1)]+1.8*(LOI-

2.1)*(LOI-2.1)*(SO3-2.0)+[-0.6*(LOI-2.1)*(LOI-2.1)*(IR-24.6)]+6.3*(LOI-

2.1)*(LOI-2.1)*(L10-30.7)+-7.1*(LOI-2.1)*(LOI-2.1)*(L30-65.8)+4.2*(LOI-

2.1)*(LOI-2.1)*(L53-88.7)+6.0*(LOI-2.1)*(SO3-2.0)*(SO3-2.0)+-0.7*(LOI-

2.1)*(SO3-2)*(IR-24.6)+[-1.0*(LOI-2.1)*(SO3-2.0)*(L1030.7)]+3.49*(LOI-

2.1)*(SO3-2)*(L30-65.8)+-3.5*(LOI-2.1)*(SO3-2)*(L53-88.7)+0.15*(LOI-

2.1)*(IR-24.6)*(IR-24.6)+[-0.9*(LOI-2.1)*(IR-24.6)*(L10-30.7)]+0.5*(LOI-

2.1)*(IR-24.6)*(L30-65.8)+0.1*(LOI-2.1)*(IR-24.6)*(L53-88.7)+[-

0.5*(LOI-2.1)*(L10-30.7)*(L10-30.7)]+2.8*(LOI-2)*(L10-30.7)*(L30-

70

65.8)+-2*(LOI-2.1)*(L10-30.7)*(L53-88.7)+0.19*(LOI-2.1)*(L30-65.

5)*(L30-65.8)+[-3.5*(LOI-2)*(L30-65.8)*(L53-88.7)]+3.4*(LOI-2)*(L53-

88.7)*(L53-88.7)+4.1*(L10-30.7)*(L10-30.7)*(SO3-2.03)+[-0.28*(L10-

30.7)*(L10-30.7)*(IR-24.6)]+[-4.9*(L10-30.7)*(L30-65.8)*(SO3-

2.0)]+0.29*(L10-30.7)*(L30-65.8)*(IR-24.6)+[-0.95*(L10-30.7)*(L53-

88.7)*(SO3-2.0)]+0.04*(L10-30.7)*(L53-88.7)*(IR-24.6)+0.37*(L30-

65.8)*(L30-65.8)*(SO3-2.0)+-0.12*(L30-65.8)*(L30-65.8)*(IR-

24.6)+4.003*(L30-65.8)*(L53-88.7)*(SO3-2)+0.1*(L30-65)*(L53-

88.7)*(IR-24.6)+[-2.6*(L53-88.7)*(L53-88.7)*(SO3-2.0)]+[-0.1*(L53-

88.7)*(L53-88.7)*(IR-24.6)] --- (5.1)

Above theoretically developed model is verified randomly for

different sets of experimental values and the response is very much

befitting with approximately 99.5% accuracy. The percentage of error

has been found to be less than 0.5%.

5.1.3. Significance of single and multiple interactions

The significance of single constituent as well as multiple

interaction constituents is shown in Table 5.2, generated in JMP

statistical analysis

71

Table 5.2: Significance of single and multiple constituents interaction on

compressive strength of one day

S.No Parameter Probability Level of significance

1 LOI 0.0029* significant

2 SO3 0.1179 Non significant

3 IR 0.0200* significant

4 L10 0.0403* significant



7 (LOI-2.15761)*(LOI-2.15761) <.0001* significant

8 (LOI-2.15761)*(SO3-2.03871) 0.0007* significant

9 (LOI-2.15761)*(IR-24.6315) 0.8209 Non significant

10 (LOI-2.15761)*(L10-30.7222) 0.0080* significant

11 (LOI-2.15761)*(L30-65.8325) <.0001* significant

12 (LOI-2.15761)*(L53-88.784) 0.2484 Non significant

13 (SO3-2.03871)*(SO3-2.03871) 0.7677 Non significant

14 (SO3-2.03871)*(IR-24.6315) <.0001* significant

15 (SO3-2.03871)*(L10-30.7222) 0.3985 Non significant

16 (SO3-2.03871)*(L30-65.8325) 0.0024* significant

17 (SO3-2.03871)*(L53-88.784) <.0001* significant

18 (IR-24.6315)*(IR-24.6315) 0.0005* significant

19 (IR-24.6315)*(L10-30.7222) 0.0931 Non significant



22 (L10-30.7222)*(L10-30.7222) 0.0001* significant

23 (L10-30.7222)*(L30-65.8325) 0.0037* significant

24 (L10-30.7222)*(L53-88.784) <.0001* significant

25 (L30-65.8325)*(L30-65.8325) <.0001* significant

26 (L30-65.8325)*(L53-88.784) 0.0351* significant

27 (L53-88.784)*(L53-88.784) 0.0814 Non significant

28 (LOI-2.15761)*(LOI-2.15761)*(LOI-2.15761) 0.0410* significant

29 (LOI-2.15761)*(LOI-2.15761)*(SO3-2.03871) 0.3026 Non significant

30 (LOI-2.15761)*(LOI-2.15761)*(IR-24.6315) 0.0002* significant

31 (LOI-2.15761)*(LOI-2.15761)*(L10-30.7222) 0.0025* significant

32 (LOI-2.15761)*(LOI-2.15761)*(L30-65.8325) <.0001* significant


34 (LOI-2.15761)*(SO3-2.03871)*(SO3-2.03871) <.0001* significant

35 (LOI-2.15761)*(SO3-2.03871)*(IR-24.6315) 0.0006* significant

36 (LOI-2.15761)*(SO3-2.03871)*(L10-30.7222) 0.5689 Non significant

37 (LOI-2.15761)*(SO3-2.03871)*(L30-65.8325) 0.0268* significant


39 (LOI-2.15761)*(IR-24.6315)*(IR-24.6315) <.0001* significant

40 (LOI-2.15761)*(IR-24.6315)*(L10-30.7222) 0.0018* significant

41 (LOI-2.15761)*(IR-24.6315)*(L30-65.8325) 0.0028* significant

42 (LOI-2.15761)*(IR-24.6315)*(L53-88.784) 0.4082 Non significant

43 (LOI-2.15761)*(L10-30.7222)*(L10-30.7222) 0.6102 Non significant

44 (LOI-2.15761)*(L10-30.7222)*(L30-65.8325) 0.0207* significant





49 (L10-30.7222)*(L10-30.7222)*(SO3-2.03871) <.0001* significant

50 (L10-30.7222)*(L10-30.7222)*(IR-24.6315) <.0001* Significant

51 (L10-30.7222)*(L30-65.8325)*(SO3-2.03871) <.0001* Significant

52 (L10-30.7222)*(L30-65.8325)*(IR-24.6315) 0.0008* Significant

53 (L10-30.7222)*(L53-88.784)*(SO3-2.03871) 0.2704 Non significant

54 (L10-30.7222)*(L53-88.784)*(IR-24.6315) 0.6812 Non significant







72

5.1.3.1 Significance of single constituent interactions

The response of statistical analysis using the data of physical

constituents (<10, <30, <53 ) as well as chemical constituents (LOI,

IR, SO3) are plotted as whole model plot and leverage plots.

Figure 5.1: Response of ‘1’ Day strength using JMP statistical analysis

The actual and predicted data of compressive strength is plotted

in Figure 5.1 for 1 Day results. The high R2 value (0.99) indicates good

fit between actual values and predicted response. The horizontal

dashed line indicates the mean. When all the constituents were

analyzed with single interaction and the R2 found to be feeble.

Further interaction effect of two constituents was analyzed and the R2

value found to be increasing to 0.76, further more interaction of three

constitutions was analyzed and the R2 found to be befitting closing to

1, which infers the strength development takes place not because of

any single constituent, but interaction of multiple constituents.

73

Figure 5.2: LOI Leverage Plot for 1 day strength

(A plot between Loss on Ignition and 1 day compressive strength)

The leverage plot for Loss on Ignition was plotted in Figure 5.2,

for 1 Day Strength of cement. LOI basically infers presence of organic

material.

From the Fig 5.2, the probability value noticed as 0.0029, as the

value is less than 0.05 the parameter LOI can be considered as a

Significant Property. The solid straight line is also seems inclined.

This also reveals that LOI was a significant property.

Coefficient of LOI in equation 5.1 is observed, -4.340, which

indicates that the strength decreases with increasing Loss on Ignition

value. It means higher strengths values are obtained with lower LOI

values.

74

Figure 5.3: SO3 Leverage Plot for 1 day strength

(A plot between SO3 and 1 day compressive strength)

Figure 5.3, showing the leverage plot for SO3 % of cement. The

probability value observed as 0.1179, as this value greater than 0.05,

the SO3 can not be a significant constituent.

Coefficient of SO3 in equation 5.1 is also observed -6.032, which

is a negative number, and it can be inferred that the strength

decreases with increase in SO3%. The solid incline line (regression

line) shows some degree of significance. It infers that some proportion

of SO3 is required to maintain.

75

Figure 5.4: IR Leverage Plot for 1 day strength

(A plot between insoluble residue and 1 day compressive strength)

Figure 5.4 is the leverage plot was drawn for Insoluble Residue,

for 1 Day Strength of cement. Insoluble Residue infers presence of fly

ash in cement. From the Fig 5.4, the probability value noticed as 0.02,

as the value is less than 0.05 the parameter IR also can be considered

as a Significant Property. The solid line (regression line) is also seems

inclined. This also reveals that IR was a significant property.

Coefficient of IR in eq. 5.1, is observed as 0.568; hence this can

be said that one day strength increases with increasing IR value.

76

Figure 5.5: L10 Leverage Plot for 1 day strength

(A plot between <10 µm particles and 1 day compressive strength)

Figure 5.5 is the leverage plot for <10 micron particles, for 1

Day Strength of cement. The Figure 5.5 infers that percentage of <10

micron particles in cement mixture effect cement strength.

From the Figure 5.5, the probability value noticed as 0.0403, as

the value is less than 0.05 the parameter <10 can be considered as a

Significant Property. The solid line (regression line) is also seems

inclined. This also reveals that <10 was a significant property.

The Coefficient of <10 µm in eq. 5.1, is also observed as -1.811,

hence this can be said that the strength decreases with increasing <10

for one day strength. It means to result higher strengths with lower

<10 values.

77

Figure 5.6: L30 Leverage plot for 1 day strength


Figure 5.6, is leverage plot for <30 micron particles, for 1 Day

strength of cement and it indicates that <30micron particles will have

influence on cement strength. From the Figure 5.6, the probability

value noticed as 0.001, as the value is less than 0.05 the parameter

<30 can be considered as a Significant Property. The solid line

(regression line) is also seems inclined. This also reveals that <30 was

a significant property.

The coefficient of <30 µm in eq. 5.1, is also as observed as

3.003, hence this can be said that the strength increases with

increasing <30 for one day strength. It means to result higher

strengths with higher <30 values.

78

Figure 5.7: L53 Leverage plot for 1 day strength


The leverage plot was drawn for <53 micron particles, for 1 Day

Strength of cement in Figure 5.7, which indicates that percentage of

<53 micron particles will have influence on cement mixture.

It may be observed from Figure 5.7, that the probability value is

0.0015, as the value is less than 0.05 the parameter <53 can be

considered as a Significant Property. The solid line (regression line) is

also seems inclined. This also reveals that <53 was a significant

property.

The coefficient of <53 µm in eq. 5.1, observed as -2.545, hence

this can be said that the strength decreases with increasing <53

micron particles, for one day strength. In other words one may say

that higher strengths with lesser <53 values.

79

5.1.3.2 Significance of multiple constituent interactions

The multiple interactions of physical constituents (<10,

<30 and <53) and chemical constituents (LOI, IR, SO3) of all the 88

cement samples are shown in terms of leverage plots are plotted in

cluster of Figures 5.8.

80

LOI*LOI

Leverage Plot

LOI*SO3

Leverage Plot

LOI*IR

Leverage Plot

1.8

LOI*L10

Leverage Plot

LOI*L30

Leverage Plot

LOI*L53

Leverage Plot

SO3*SO3

Leverage Plot

SO3*IR

Leverage Plot

81

SO3*L10

Leverage Plot

SO3*L30

Leverage Plot

SO3*L53

Leverage Plot

IR*IR

Leverage Plot

IR*L10

Leverage Plot

IR*L30

Leverage Plot

IR*L53

Leverage Plot

L10*L10

Leverage Plot

82

L10*L30 Leverage Plot





LOI*LOI*LOI Leverage Plot

LOI*LOI*SO3 Leverage Plot

LOI*LOI*IR Leverage Plot

83

LOI*LOI*L10 Leverage Plot



LOI*SO3*SO3 Leverage Plot

LOI*SO3*IR Leverage Plot

LOI*SO3*L10 Leverage Plot



84

LOI*IR*IR Leverage Plot

LOI*IR*L10 Leverage Plot



LOI*L10*L10 Leverage Plot




85



L10*L10*SO3 Leverage Plot

L10*L10*IR Leverage Plot





86







Cluster of Figures 5.8: Response of multiple interactions of physical

and chemical constituents for 1 day compressive strength of cement

samples

87

[Note on Multiple Graphical legend of 88 cement samples: Y axis- ‘1’ day

cured compressive strength of cement leverage residuals; X axis – leverage of

constituent(s) interaction for ‘1’ day compressive strength of cement; horizontal

dotted line-mean line; dark inclined line – regression line; inclined dotted line(s)-

confidence curves; L10-Less than 10µm particles; L30-Less than 30µm particles;

L53-Less than 53µm particles; LOI-loss on ignition; IR-insoluble residue;SO3-

Sulphur Anhydride(SO3)]

The constituents viz LOI, IR, <10, <30 and <53 found to be

significant for 1 day compressive strength, whereas SO3 found to be

non significant, and the significance of multiple constituent

interactions is shown in Table 5.2 and cluster of Figures 5.8

88

1.2. Estimation of 3 day compressive strength

1.2.1.Effect of physical and chemical constituents on 3 day

Compressive Strength

All cement samples (88) were subjected to analyze for physical

and chemical constituents, and the results as well as response in

terms of compressive strength for 3 day(s) is shown in the Table 5.3.

The values of <10 µm found to be in the range of 15.59 % to

36.79 %, and the corresponding one day strength values are 22.39

MPa and 34.17 MPa, which infers that three day(s) strength is directly

proportional to percentage of <10 µm particles. Good values of three

day(s) compressive strength were observed to be in the range of 23 % -

33% of <10 µm particles.


74.18 %, and the corresponding three day(s) strength values are 22.39

MPa and 34.17 MPa, which infers that one day strength is directly

proportional to percentage of <30 µm particles, however in some

samples three day(s) strength found to be high even if the percentage

is approximately 65%, which could be because of other enriched

parameters like blaines, IR, LOI. Good values of three day(s)

compressive strength were observed to be in the range of 63 % - 73%

of <30 µm particles.



MPa and 33.85 MPa. The trend of average values shows to be

89

decreasing compressive strength values at increasing <53 µm

particles. Good values of three day(s) compressive strength were

observed to be in the range of 80 % - 90% of <53 µm particles.

From the physical constituents of <10, <30 and <53 higher

percentage of finer values are favoring one day and three day(s)

strength, in line with established research[20].

The values of Loss on Ignition, SO3, IR, are found to be in the

range as specified by BIS [116]. LOI values are observed to be in the

range of 1 to 4.1, the values of SO3 are observed to be in the range of

0.45 to 2.98, and the values of IR are observed to be in the range of 15

to 38.9.

Three day(s) strength at minimum LOI value (1) found to be

23.24, which is a moderately a good strength, whereas at maximum

LOI value (4) the strength found to be 41.75, which is a very good

value. With the values of LOI it can be inferred that the values has no

direct influence towards strength development, the strength depends

on other constituents, however in whole set of samples it had been

observed that higher LOI values are yielding lesser three day

strengths, in most of the cases and in some of the cases LOI values

are compensated with other constituents like <10, <30, and <53,

which are associated with bulk density, tapped density, Husner’s ratio

and surface area. Good three values of three day(s) strength were

observed in the LOI range of 0 % - 2.8%.

Three day(s) strength at minimum SO3 value (0.45) found to be

35.79, which is a very good strength, whereas at maximum SO3 value

90

(2.98) the strength found to be 35.65, which is also a good strength.

With the values of SO3 it can be inferred that not much impact is

observed for three day(s) strength. Three day(s) strength values were

observed to be good for SO3 in the range of 1.5 % to 2.5 %

Three day(s) strength at minimum IR value (15.0) found to be

30.24 MPa, which is a good strength, whereas at maximum IR value

(38.9) the strength found to be 34.9 MPa, which is a good value. It is

observed that higher percentage of IR value reducing three days

strength; however with in a specific range the three days strength

observed to be good. Three day(s) compressive strength values were

observed to be good, in IR range values of 18 % - 27 %.

91



S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles

3 days Strength (MPa)

1 2.0 1.21 32.6 19.87 49.21 74.52 21.58

2 1.0 1.84 28.7 33.10 69.31 88.46 27.87

3 1.0 2.84 28.6 27.79 62.15 84.49 23.41

4 2.0 1.51 28.8 33.96 70.73 89.24 28.15

5 1.0 1.68 19.8 36.14 73.32 91.36 33.85

6 1.9 2.31 19.1 34.53 71.52 89.62 29.29

7 1.0 2.03 19.7 26.60 66.81 85.22 21.58

8 1.8 1.90 31.0 23.18 54.96 79.42 30.92

9 2.4 1.82 26.1 20.80 51.10 76.36 19.60

10 1.0 1.74 25.1 24.17 56.63 76.72 23.24

11 2.5 2.06 16.6 22.74 54.35 79.00 22.53

12 3.3 2.02 21.4 27.33 61.91 84.50 25.24

13 1.9 1.92 27.0 36.79 74.18 90.70 34.17

14 2.6 2.64 23.7 27.50 71.99 85.50 30.17

15 1.3 1.27 26.5 33.54 74.08 90.73 34.30

16 2.8 1.13 19.8 34.34 72.99 90.38 32.61

17 2.0 2.09 20.4 33.58 73.10 90.37 33.30

18 3.3 1.96 24.7 22.21 53.85 78.83 30.58

19 2.2 1.51 22.1 25.34 66.64 82.20 26.50

20 2.0 1.75 36.7 27.40 61.94 84.52 31.10

21 2.7 1.65 25.1 29.01 64.50 86.15 27.00

22 2.1 1.65 19.1 29.19 64.59 86.14 35.00

23 2.2 1.30 23.0 28.08 63.15 85.35 34.70

24 2.8 1.81 22.1 22.47 53.86 78.55 29.50

25 1.5 1.26 21.5 25.14 63.71 85.98 30.85

26 2.6 2.43 23.9 28.24 62.80 84.90 24.90

27 2.3 2.36 21.8 26.14 66.94 86.43 28.29

28 2.3 2.81 27.4 30.55 66.18 86.91 28.55

29 2.0 1.47 36.0 31.10 66.91 87.31 31.32

30 1.9 2.09 29.7 26.87 60.81 83.67 25.51

31 2.3 2.70 24.9 22.94 54.47 78.97 21.80

32 1.8 2.50 13.9 31.00 72.38 89.14 37.21

33 2.9 2.80 27.5 27.01 63.91 83.66 32.75

34 1.7 2.10 27.5 34.03 70.76 89.24 30.24

35 2.0 2.40 15.5 25.19 58.34 78.01 33.76

36 2.4 2.22 23.5 28.14 69.94 84.43 29.90

37 2.0 2.0 29.3 33.88 70.23 89.08 25.90

38 2.2 2.30 30.6 30.77 66.29 86.90 27.40

39 2.4 1.10 30.4 29.12 64.11 85.71 28.30

40 1.6 1.79 27.0 26.87 63.40 81.12 29.02

41 1.0 2.95 33.5 29.25 64.18 85.70 28.82

42 2.0 1.99 23.8 30.05 65.48 86.52 34.23

43 2.0 1.34 27.0 29.11 64.11 85.71 25.98

44 4.1 2.15 18.2 31.54 67.12 87.29 41.75

92

S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles


45 3.2 1.57 38.9 32.93 69.23 88.47 34.91

46 1.4 2.90 31.3 34.13 70.85 89.23 31.66

47 1.5 1.78 31.5 31.74 67.60 87.69 34.23

48 2.5 2.02 34.5 36.14 73.32 91.30 25.10

49 2.3 1.82 34.9 31.16 66.94 87.30 32.68

50 3.0 0.45 21.5 28.79 63.52 85.30 35.79

51 3.0 2.98 19.6 32.36 68.47 88.00 35.65

52 2.9 1.99 23.3 22.88 54.43 78.90 22.32

53 1.2 2.06 23.0 25.20 63.74 84.78 33.22

54 3.0 1.92 36.1 22.50 53.85 78.55 26.38

55 2.2 2.92 23.1 22.64 53.88 78.53 26.38

56 1.5 2.54 30.6 34.21 70.84 89.33 33.89

57 1.5 1.78 18.2 25.97 63.55 82.66 38.49

58 2.5 1.90 33.0 33.44 66.55 86.09 28.55

59 2.3 2.70 24.4 24.59 57.30 78.14 27.06

60 2.2 1.50 19.0 25.75 59.04 82.15 33.49

61 2.2 1.90 26.9 29.49 64.74 86.10 32.20

62 3.0 2.30 20.1 26.62 60.30 83.20 33.26

63 2.9 2.0 24.0 21.08 51.62 76.80 24.69

64 1.7 2.0 28.0 22.13 53.28 78.12 23.0

65 1.5 1.50 20.6 20.82 51.12 76.35 25.84

66 2.4 1.90 24.8 22.71 54.33 79.00 26.45

67 1.8 2.50 22.5 21.26 51.73 76.70 31.46

68 2.3 1.80 31.9 24.23 56.67 80.70 24.66

69 2.7 2.70 27.0 30.75 66.28 86.90 24.27

70 2.0 2.30 31.5 29.32 64.22 85.70 31.12

71 1.4 1.50 19.7 21.55 57.60 77.70 37.59

72 2.1 2.0 18.1 27.75 62.13 84.40 30.96

73 3.0 2.30 23.0 26.38 60.17 83.20 26.86

74 2.3 1.60 24.4 36.14 73.32 91.30 24.46

75 2.3 2.0 30.9 23.89 56.10 80.28 27.49

76 1.2 2.10 25.1 25.97 59.55 76.80 27.18

77 2.0 2.69 22.7 26.76 65.78 83.00 23.52

78 2.3 1.65 27.0 26.42 57.14 84.40 27.87

79 3.0 2.0 21.7 27.76 62.13 84.40 25.41

80 2.4 1.84 23.4 25.70 51.04 76.37 19.88

81 2.4 2.11 15.0 20.80 51.11 76.37 30.24

82 2.5 2.0 15.5 26.42 63.52 81.60 41.54

83 2.5 2.12 27.5 25.77 64.72 84.70 27.90

84 1.9 1.84 31.3 19.28 48.51 74.12 28.14

85 3.2 2.10 22.1 15.59 41.23 66.60 22.39

86 2.1 2.50 24.6 19.84 49.51 75.02 25.84

87 1.8 2.0 19.5 22.89 54.79 79.00 22.32

88 2.4 2.0 23.4 19.88 49.54 75.00 25.91

Using all above values, statistical analysis of effect of individual

constituent on three day(s) compressive strength as well as combined

93

effect has been studied using JMP statistical software. An equation

is developed for three day(s) compressive strength as a function of

physical and chemical constituents like Loss On Ignition, Insoluble

Residue, Sulfuric anhydride(SO3), <10, <30, and <53 micron particles.

5.2.2. Theoretical model/equation for ‘3’ day strength

75.7-9.4*LOI+[-0.7*SO3]+[-0.7*IR]+[-1.0*L10]+2.0*L30+[-1.2*L53]+[-9.7*(LOI-

2.1)*(LOI-2.1)]+2.5*(LOI-2.1)*(SO3-2.0)+[-0.01*(LOI-2.1)*(IR-24.6)]+-2.7*(LOI-

2.1)*(L10-30.7)+3.7*(LOI-2.1)*(L30-65.8)+[-2.0*(LOI-2.1)*(L53-88.7)]+[-

2*(SO3-2.0)*(SO3-2.0)]+0.9*(SO3-2.0)*(IR-24.6)+-4.4*(SO3-2.0)*(L10-30.7)+[-

2.2*(SO3-2)*(L30-65.8)+6.9*(SO3-2)*(L53-88.7)]+[-0.001*(IR-24.6)*(IR-

24.6)]+-0.1*(IR-24.6)*(L10-30.7)+[-0.2*(IR-24.6)*(L30-65)]+0.6*(IR-24.6)*(L53-

88.7)+2.2*(L10-30.7)*(L10-30)+1.5*(L10-30)*(L30-65.8)+[-7.4*(L10-30)*(L53-

88.7)]+[-0.7*(L30-65.8)*(L30-65.8)]+1*(L30-65.8)*(L53-88.7)+2.8*(L53-

88.7)*(L53-88.7)+3.3*(LOI-2.1)*(LOI-2.1)*(LOI-2.1)+3.6*(LOI-2.1)*(LOI-

2.1)*(SO3-2)+[-0.4*(LOI-2.1)*(LOI-2.1)*(IR-24.6)]+8.1*(LOI-2.1)*(LOI-

2.1)*(L10-30.7)+[-6.0*(LOI-2.1)*(LOI-2.1)*(L30-65.8)]+0.5*(LOI-2.1)*(LOI-

2.1)*(L53-88.7)+12.5*(LOI-2.1)*(SO3-2)*(SO3-2)+[-1.7*(LOI-2.1)*(SO3-

2.0)*(IR-24.6)]+[-12.7*(LOI-2.1)*(SO3-2)*(L10-30.7)]+6.3*(LOI-2.1)*(SO3-

2)*(L30-65.8)+5.7*(LOI-2.1)*(SO3-2.0)*(L53-88.7)+0.1*(LOI-2.1)*(IR-24.6)*(IR-

24.6)+[-0.5*(LOI-2.1)*(IR-24.6)*(L10-30.7)]+0.08*(LOI-2.1)*(IR-24.6)*(L30-

65.8)+0.4*(LOI-2.1)*(IR-24.6)*(L53-88.7)+0.2*(LOI-2.1)*(L10-30.7)*(L10-

30.7)+4.2*(LOI-2.1)*(L10-30.7)*(L30-65.8)+[-6.6*(LOI-2.1)*(L10-30.7)*(L53-

88.7)]+0.8*(LOI-2.1)*(L30-65.8)*(L30-65.8)+[-5.3*(LOI-2.1)*(L30-65.8)*(L53-

88.7)]+6.2*(LOI-2.1)*(L53-88.7)*(L53-88.7)+5.5*(L10-30.7)*(L10-30.7)*(SO3-

2.0)+[-0.3*(L10-30.7)*(L10-30.7)*(IR-24.6)]+[-4.5*(L10-30.7)*(L30-65.8)*(SO3-

2.0)]+0.2*(L10-30.7)*(L30-65.8)*(IR-24.6)+[-3.4*(L10-30.7)*(L53-88.7)*(SO3-

2.0)]+0.1*(L10-30.7)*(L53-88.7)*(IR-24.6)+[-1.5*(L30-65.8)*(L30-65.8)*(SO3-

94

2.0)]+0.09*(L30-65.8)*(L30-65.8)*(IR-24.6)+8.8*(L30-65.8)*(L53-88.7)*(SO3-

2.0)+[-0.4*(L30-65.8)*(L53-88.7)*(IR-24.6)]+[-5.1*(L53-88.7)*(L53-88)*(SO3-

2)]+0.2*(L53-88)*(L53-88)*(IR-24.6)--- -- (5.2)

Above theoretically developed (eqn. 5.2) model is verified

randomly for different sets of experimental values and the response is

very much befitting with approximately 99.5% accuracy. The

percentage of error has been found to be less than 0.5%.


Significance of single constituent as well as interaction of

multiple constituents and response is shown in Table 5.4, generated

by JMP statistical analysis

95

Table 5.4: Significance of single and multiple constituents interaction

and their probable effect on 3 day compressive strength


1 LOI 0.0028* Significant


3 IR 0.1548 Non significant

4 L10 0.5763 Non significant



7 (LOI-2.15761)*(LOI-2.15761) 0.0356* Significant

8 (LOI-2.15761)*(SO3-2.03871) 0.5498 Non significant



11 (LOI-2.15761)*(L30-65.8325) 0.0002* Significant



14 (SO3-2.03871)*(IR-24.6315) 0.0708 Non significant



17 (SO3-2.03871)*(L53-88.784) 0.0064* Significant

18 (IR-24.6315)*(IR-24.6315) 0.9888 Non significant



21 (IR-24.6315)*(L53-88.784) 0.0067* Significant

22 (L10-30.7222)*(L10-30.7222) 0.0089* Significant


24 (L10-30.7222)*(L53-88.784) <.0001* Significant



27 (L53-88.784)*(L53-88.784) 0.0298* Significant

28 (LOI-2.15761)*(LOI-2.15761)*(LOI-2.15761) 0.0524 Non significant


30 (LOI-2.15761)*(LOI-2.15761)*(IR-24.6315) 0.1971 Non significant

31 (LOI-2.15761)*(LOI-2.15761)*(L10-30.7222) 0.0574 Non significant

32 (LOI-2.15761)*(LOI-2.15761)*(L30-65.8325) 0.0407* Significant


34 (LOI-2.15761)*(SO3-2.03871)*(SO3-2.03871) <.0001* significant

35 (LOI-2.15761)*(SO3-2.03871)*(IR-24.6315) 0.0003* significant




39 (LOI-2.15761)*(IR-24.6315)*(IR-24.6315) 0.0073* significant

40 (LOI-2.15761)*(IR-24.6315)*(L10-30.7222) 0.3432 significant





45 (LOI-2.15761)*(L10-30.7222)*(L53-88.784) 0.0031* Non significant

46 (LOI-2.15761)*(L30-65.8325)*(L30-65.8325) 0.3983 significant



96

In ‘3’ day compressive strength the single parameter ‘LOI’ only found

to be significant value, and all other values are non significant.

5.2.3.1 Significance of single constituent interactions



IR, SO3) are studied as whole model plot and leverage plots, of single

interactions for ’3’ day compressive strength.


The actual and predicted data was plotted in Fig. 5.9 for 3 Day

results. The good R2 (0.97) value indicates good fit between actual

values and predicted response. The horizontal dashed line indicates

the mean.

All the constituents were analyzed with single interaction and

the R2 value found to be feeble. Further interaction effect of two

constituents was analyzed and the R2 value found to be increasing,

with multiple interactions, which infers the strength development

takes place not because of any single constituent, but interaction of

multiple constituents.

97

Figure 5.10. LOI - Leverage Plot for 3 day strength

(A plot between LOI and 3 day compressive strength)

The leverage plot was drawn for Loss on Ignition, shown in

Figure 5.10 for 3 Day Strength of cement. LOI infers presence of

organic material. From the Figure 5.10, the probability value noticed

as 0.0028, as the value is less than 0.05 the parameter LOI can be

considered as a Significant Property. The solid line (regression line) is

also seems inclined. This also reveals that LOI was a significant

property.

The coefficient of LOI in eq. 5.2, is observed as -9.410, hence

this can be said that the strength decreases with increasing Loss on

Ignition value. It means to result higher strengths with lower LOI

values.

98

Figure: 5.11 SO3 - Leverage Plot for 3 day strength


Figure 5.11, showing the leverage plot for SO3 % of cement for 3

days strength. The probability value observed as 0.9229, as this value

greater than 0.05, the SO3 can not be a significant constituent.

The Coefficient of SO3 in the equatuion 5.2 os observed as, -

0.78, which is a negative number, and it can be inferred that the

strength decreases with increase in SO3%. The solid incline line

(regression line) shows some degree of significance. It infers that some

proportion of SO3 is required to maintain.

99

Figure 5.12: IR - Leverage Plot for 3 day strength

(A plot between IR and 3 day compressive strength)

The leverage plot was drawn for Insoluble Residue, as shown in

Figure 5.12, for 3 day strength of cement. The presence of Insoluble

Residue may be due to the presence of fly ash in cement.

From the Figure 5.12, the probability value noticed as 0.1548,

as the value is more than 0.05 the parameter IR cannot be a

Significant Property. The solid line (regression line) is also seems

inclined. This also reveals that IR was a significant property within

stipulated values.

The coefficient of IR in equation 5.2, observed as -0.725, hence

this can be said that three day strength decreases with increasing IR

value.

100

Figure 5.13: L10 - Leverage Plot for 3 day strength

(A plot between <10 µm and 3 day compressive strength)

The leverage plot 5.13, was drawn for <10 micron particles, for 3

day strength of cement. <10micron particles infers percentage of <10

micron particles in cement mixture.


the value is more than 0.05 the parameter <10 cannot be a significant

Property. The solid line (regression line) is also seems inclined. This

also reveals that <10 was a significant property within stipulated

range.

The coefficient of <10 in equation 5.2, observed as -1.02, hence

this can be said that the strength decreases with increasing <10 for

one day strength. It means to result higher strengths with lower <10

values.

101

Figure 5.14: L30 - Leverage Plot


The leverage plot, was drawn for <30 micron particles, shown in

Figure 5.14, for 3 Day Strength of cement. From the Figure 5.14, the

probability value noticed as 0.255, as the value is more than 0.05 the

parameter <30 cannot be a significant Property. The solid line


a significant property, which infers significance within the range.

The coefficient of <30 in equation 5.2, observed as 2.06, hence

this can be said that the strength increases with increasing <30

particles for three day strength. It indicates higher strengths may be

obtained by maintaining high values of <30 particles.

102



The leverage plot, was drawn for <53 micron particles, as shown

in Figure 5.15, for 3 day Strength of cement. From the Figure 5.15,

the probability value noticed as 0.43, as the value is more than 0.05

the parameter <53 cannot be a Significant Property. The solid line


a significant property within the stipulated range.

The coefficient of <53 in the equation 5.2, observed as -1.219,

hence this shows, that the strength decreases with increasing <53

micron particles, for one day strength.

103

5.2.3.2 Significance of multiple constituent interactions

Response of statistical analysis of 88 samples of physical

constituents (<10, <30 and <53) and chemical constituents (LOI, IR,

SO3) are shown below in terms of leverage plots of multiple

interactions. Significance of multiple interactions, and response, is

shown in following cluster of Figures 5.16.

104

Effect of multiple interactions of constituents, and probable

values for 3 day strength

LOI*LOI Leverage Plot

LOI*SO3

Leverage Plot

LOI*IR

Leverage Plot

LOI*L10

Leverage Plot

LOI*L30 Leverage Plot

LOI*L53

Leverage Plot

SO3*SO3

Leverage Plot

SO3*IR

Leverage Plot

105

SO3*L10 Leverage Plot

SO3*L30

Leverage Plot

SO3*L53

Leverage Plot

IR*IR

Leverage Plot

IR*L10 Leverage Plot

IR*L30

Leverage Plot

IR*L53

Leverage Plot

L10*L10

Leverage Plot

106


L10*L53

Leverage Plot

L30*L30

Leverage Plot

L30*L53

Leverage Plot




LOI*LOI*IR

Leverage Plot

107





LOI*SO3*IR Leverage Plot




108

LOI*IR*IR Leverage Plot

LOI*IR*L10

Leverage Plot

LOI*IR*L30

Leverage Plot

LOI*IR*L53

Leverage Plot





109




L10*L10*IR

Leverage Plot


L10*L30*IR

Leverage Plot


L10*L53*IR

Leverage Plot

110


L30*L30*IR

Leverage Plot



L53*L53*IR

Leverage Plot

L30*L53*IR

Leverage Plot

Figures 5.16: Response of multiple interactions of physical and

chemical constituents for 3 day compressive strength

of cement samples.

[Note on Multiple Graphical legend of 88 cement samples: Y axis- leverage residuals

of ‘3’ day(s) cured compressive strength of cement; X axis – leverage of constituent(s)

interaction for ‘3’ day(s) compressive strength of cement; horizontal dotted line-mean

line; dark inclined line – regression line; inclined dotted line(s)-confidence curves;

L10-Less than 10µm particles; L30-Less than 30µm particles; L53-Less than 53µm

particles; LOI-loss on ignition; IR-insoluble residue;SO3-Sulphur Anhydride(SO3)]

111

The constituent LOI only is found to be significant for 3 day

compressive strength, whereas IR, SO3, <10, <30, <53 found to be non

significant. The significance of multiple constituents is shown in Table

5.4, and cluster of Figures 5.16.

112

1.3. Estimation of 7 day strength

1.3.1.Effect of physical and chemical constituents on 7 day

strength





36.79 %, and the corresponding seven day(s) strength values are

34.57 MPa and 37.7 MPa. Good values of seven day(s) compressive

strength were observed to be in the range of 23 % - 33% of <10 µm

particles.


74.18 %, and the corresponding seven day(s) strength values are

34.57 MPa and 37.7 MPa. Good values of seven day(s) compressive


particles.



MPa and 34.30 MPa. Good values of seven day(s) compressive


particles.




113


to 38.9.

Seven day(s) strength at minimum LOI value (1.0) found to be

30.17 MPa, which is a moderately a good strength, whereas at

maximum LOI value (4.0) the strength found to be 50 MPa, which is a

very good value. Good values of seven day(s) strength were observed

in the LOI range of 0 % - 2.8%.

Seven day(s) strength at minimum SO3 value (0.45) found to be

48.58 MPa, which is a very good strength, whereas at maximum SO3

value (2.98) the strength found to be 45.36 MPa, which is also a good

strength. However, the decrease is marginal. With the values of SO3 it

can be inferred that not much impact of SO3 is observed for seven

day(s) strength. Seven day(s) strength values were observed to be good

in SO3 range of 1.5 % to 2.5 %

In general the value of IR increases the Seven day(s) strength is

decreasing. However at minimum IR value (15.0) found to be 30.24

MPa, which is a good strength, whereas at maximum IR value (38.9)

the strength found to be 38.70 MPa, which is a good value. It may be

attributed due to the fact that the effect of other parameters are

dominating. Seven day(s) compressive strength values were observed

to be good, in IR range values of 18 % - 27 %.

114



S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles

7 days Strength

(MPa)

1 2.0 1.21 32.6 19.87 49.21 74.52 32.75

2 1.0 1.84 28.7 33.10 69.31 88.46 32.88

3 1.0 2.84 28.6 27.79 62.15 84.49 44.55

4 2.0 1.51 28.8 33.96 70.73 89.24 35.32

5 1.0 1.68 19.8 36.14 73.32 91.36 34.30

6 1.9 2.31 19.1 34.53 71.52 89.62 31.81

7 1.0 2.03 19.7 26.60 66.81 85.22 34.91

8 1.8 1.90 31.0 23.18 54.96 79.42 39.38

9 2.4 1.82 26.1 20.80 51.10 76.36 35.93

10 1.0 1.74 25.1 24.17 56.63 76.72 30.17

11 2.5 2.06 16.6 22.74 54.35 79.00 27.54

12 3.3 2.02 21.4 27.33 61.91 84.50 36.17

13 1.9 1.92 27.0 36.79 74.18 90.70 37.70

14 2.6 2.64 23.7 27.50 71.99 85.50 34.50

15 1.3 1.27 26.5 33.54 74.08 90.73 39.50

16 2.8 1.13 19.8 34.34 72.99 90.38 35.30

17 2.0 2.09 20.4 33.58 73.10 90.37 42.30

18 3.3 1.96 24.7 22.21 53.85 78.83 33.16

19 2.2 1.51 22.1 25.34 66.64 82.20 41.30

20 2.0 1.75 36.7 27.40 61.94 84.52 44.30

21 2.7 1.65 25.1 29.01 64.50 86.15 34.80

22 2.1 1.65 19.1 29.19 64.59 86.14 44.50

23 2.2 1.30 23.0 28.08 63.15 85.35 45.40

24 2.8 1.81 22.1 22.47 53.86 78.55 36.94

25 1.5 1.26 21.5 25.14 63.71 85.98 49.73

26 2.6 2.43 23.9 28.24 62.80 84.90 33.35

27 2.3 2.36 21.8 26.14 66.94 86.43 38.63

28 2.3 2.81 27.4 30.55 66.18 86.91 40.60

29 2.0 1.47 36.0 31.10 66.91 87.31 42.22

30 1.9 2.09 29.7 26.87 60.81 83.67 34.17

31 2.3 2.70 24.9 22.94 54.47 78.97 33.90

32 1.8 2.50 13.9 31.00 72.38 89.14 48.04

33 2.9 2.80 27.5 27.01 63.91 83.66 47.36

34 1.7 2.10 27.5 34.03 70.76 89.24 39.33

35 2.0 2.40 15.5 25.19 58.34 78.01 41.95

36 2.4 2.22 23.5 28.14 69.94 84.43 36.63

37 2.0 2.0 29.3 33.88 70.23 89.08 43.70

38 2.2 2.30 30.6 30.77 66.29 86.90 40.60

39 2.4 1.10 30.4 29.12 64.11 85.71 37.90

40 1.6 1.79 27.0 26.87 63.40 81.12 37.69

41 1.0 2.95 33.5 29.25 64.18 85.70 47.09

42 2.0 1.99 23.8 30.05 65.48 86.52 47.90

43 2.0 1.34 27.0 29.11 64.11 85.71 35.79

44 4.1 2.15 18.2 31.54 67.12 87.29 50.0

115

S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles

7 days Strength

(MPa)

45 3.2 1.57 38.9 32.93 69.23 88.47 48.72

46 1.4 2.90 31.3 34.13 70.85 89.23 42.01

47 1.5 1.78 31.5 31.74 67.60 87.69 44.52

48 2.5 2.02 34.5 36.14 73.32 91.30 35.86

49 2.3 1.82 34.9 31.16 66.94 87.30 42.35

50 3.0 0.45 21.5 28.79 63.52 85.30 48.58

51 3.0 2.98 19.6 32.36 68.47 88.00 45.26

52 2.9 1.99 23.3 22.88 54.43 78.90 32.00

53 1.2 2.06 23.3 25.20 63.74 84.78 49.19

54 3.0 1.92 36.1 22.50 53.85 78.55 34.78

55 2.2 2.92 23.1 22.64 53.88 78.53 35.76

56 1.5 2.54 30.6 34.21 70.84 89.33 46.48

57 1.5 1.78 18.2 25.97 63.55 82.66 49.83

58 2.5 1.90 33.0 33.44 66.55 86.09 33.15

59 2.3 2.70 24.4 24.59 57.30 78.14 38.49

60 2.2 1.50 19.0 25.75 59.04 82.15 43.10

61 2.2 1.90 26.9 29.49 64.74 86.10 41.74

62 3.0 2.30 20.1 26.62 60.30 83.20 40.79

63 2.9 2.00 24.0 21.08 51.62 76.80 30.65

64 1.7 2.00 28.0 22.13 53.28 78.12 26.85

65 1.5 1.50 20.6 20.82 51.12 76.35 33.02

66 2.4 1.90 24.8 22.71 54.33 79.00 31.86

67 1.8 2.50 22.5 21.26 51.73 76.70 42.08

68 2.3 1.80 31.9 24.23 56.67 80.70 34.18

69 2.7 2.70 27.0 30.75 66.28 86.90 32.86

70 2.0 2.30 31.5 29.32 64.22 85.70 42.14

71 1.4 1.50 19.7 21.55 57.60 77.70 46.20

72 2.1 2.00 18.13 27.75 62.13 84.40 41.22

73 3.0 2.30 23.0 26.38 60.17 83.20 39.92

74 2.3 1.60 24.4 36.14 73.32 91.30 37.67

75 2.3 2.00 30.9 23.89 56.10 80.28 34.23

76 1.2 2.10 25.1 25.97 59.55 76.80 31.21

77 2.0 2.69 22.7 26.76 65.78 83.00 32.69

78 2.3 1.65 27.0 26.42 57.14 84.40 37.88

79 3.0 2.00 21.7 27.76 62.13 84.40 33.62

80 2.4 1.84 23.4 25.70 51.04 76.37 31.56

81 2.4 2.11 15.0 20.80 51.11 76.37 38.70

82 2.5 2.00 15.5 26.42 63.52 81.60 51.49

83 2.5 2.12 27.5 25.77 64.72 84.70 39.71

84 1.9 1.84 31.3 19.28 48.51 74.12 39.11

85 3.2 2.10 22.1 15.59 41.23 66.60 34.57

86 2.1 2.50 24.6 19.84 49.51 75.02 32.58

87 1.8 2.00 19.5 22.89 54.79 79.00 30.51

88 2.4 2.00 23.4 19.88 49.54 75.00 37.89

116

Using all above values (Table 5.5), statistical analysis of effect of

individual constituent on seven day(s) compressive strength as well as

combined effect has been studied using JMP statistical software.

The equation is developed for seven day(s) compressive strength

as a function of physical and chemical constituents like Loss On

Ignition, Insoluble Residue, Sulfuric anhydride, <10, <30, and <53

micron particles.

5.3.2. Theoretical model/equation for ‘7’ day strength -13.8-16.8*LOI+15.4*SO3+[-1.1*IR+2.6*L10]+1.5*L30+[-3.7*L53]+[-

14.3*(LOI-2)*(LOI-2)]+[-4.5*(LOI-2.1)*(SO3-2.0)]+0.8*(LOI-2.1)*(IR-

24.6)+[-0.7*(LOI-2)*(L10-30.7)]+2.6*(LOI-2)*(L30-65.8)+[-3*(LOI-

2)*(L53-88.7)]+[-5.5*(SO3-2)*(SO3-2)]+1.6*(SO3-2.0)*(IR-24.6)+[-

5.5*(SO3-2)*(L10-30.7)]+1.8*(SO3-2)*(L30-65.8)+1.9*(SO3-2)*(L53-

88.7)+0.03*(IR-24)*(IR-24)+[-0.1*(IR-24)*(L10-30.7)]+[-0.1*(IR-

24)*(L30-65.8)]+0.7*(IR-24)*(L53-88.7)+1.0*(L10-30.7)*(L10-

30.7)+2.7*(L10-30.7)*(L30-65.8)+[-7.7*(L10-30.7)*(L53-88)]+[-0.6*(L30-

65.8)*(L30-65.8)]+[-0.04*(L30-65.8)*(L53-88.7)]+4.0*(L53-88.7)*(L53-

88.7)+[-0.2*(LOI-2.1)*(LOI-2.1)*(LOI-2.1)]+4.1*(LOI-2.1)*(LOI-

2.1)*(SO3-2.0)+[-1.0*(LOI-2.1)*(LOI-2.1)*(IR-24.6)]+3.3*(LOI-2.1)*(LOI-

2)*(L10-30.7)+[-9.5*(LOI-2.1)*(LOI-2.1)*(L30-65.8)]+10.9*(LOI-2.1)

*(LOI-2)*(L53-88.7)+19.2*(LOI-2.1)*(SO3-2.0)*(SO3-2.0)+[-2.2*(LOI-2.1)

*(SO3-2.0)*(IR-24.6)]+[-16.1*(LOI-2.1)*(SO3-2.0)*(L10-30.7)]+2.2*(LOI-

2)*(SO3-2.0)*(L30-65.8)+15.1*(LOI-2.1)*(SO3-2.0)*(L53-88.7)+0.2*(LOI-

2)*(IR-24.6)*(IR-24.6)+[-1.7*(LOI-2.1)*(IR-24.6)*(L10-30.7)]+1.0*(LOI-

117

2.1)*(IR-24.6)*(L30-65.8)+0.09*(LOI-2.1)*(IR-24.6)*(L53-

88.7)+1.9*(LOI-2)*(L10-30.7)*(L10-30.7)+0.9*(LOI-2)*(L10-30.7)*(L30-

65.8)+[-3.9*(LOI-2)*(L10-30.7)*(L53-88.7)]+2.5*(LOI-2)*(L30-

65.8)*(L30-65.8)+[-7.3*(LOI-2)*(L30-65.8)*(L53-88.7)]+6*(LOI-2)*(L53-

88.7)*(L53-88.7)+5.5*(L10-30.7)*(L10-30.7)*(SO3-2)+[-0.1*(L10-

30.7)*(L10-30.7)*(IR-24)]+[-5.6*(L10-30)*(L30-65.8)*(SO3-2)]+0.4*(L10-

30.7)*(L30-65.8)*(IR-24.6)+[-2.4*(L10-30)*(L53-88.7)*(SO3-2.0)]+[-

0.4*(L10-30.7)*(L53-88.7)*(IR-24.6)]+[-3.4*(L30-65.8)*(L30-65.8)*(SO3-

2)]+0.1*(L30-65.8)*(L30-65.8)*(IR-24)+16*(L30-65.8)*(L53-88.7)*(SO3-

2.0)+[-0.6*(L30-65.8)*(L53-88.7)*(IR-24.6)]+[-11.8*(L53-88.7)*(L53-

88.7)*(SO3-2.0)]+0.6*(L53-88.7)*(L53-88.7)*(IR-24.6)---- (5.3)

Above theoretically developed model (eq 5.3) is verified randomly

for different sets of experimental values and the response is very

much befitting with approximately 99.5% accuracy. The percentage of

error has been found to be less than 0.5%.


Significance of single constituent as well as interaction of

multiple constituents and response is shown in Table 5.6, developed

by JMP statistical analysis

118

Table 5.6: Significance of single and multiple constituents interaction

and their probable effect on ‘7’ day compressive strength


1 LOI <.0001* significant


3 IR 0.0447* significant




7 (LOI-2.15761)*(LOI-2.15761) 0.0074* significant

8 (LOI-2.15761)*(SO3-2.03871) 0.3492 Non significant





13 (SO3-2.03871)*(SO3-2.03871) 0.0170* significant

14 (SO3-2.03871)*(IR-24.6315) 0.0060* significant




18 (IR-24.6315)*(IR-24.6315) 0.2652 Non significant



21 (IR-24.6315)*(L53-88.784) 0.0047* Significant


23 (L10-30.7222)*(L30-65.8325) 0.0047* Significant

24 (L10-30.7222)*(L53-88.784) <.0001* Significant



27 (L53-88.784)*(L53-88.784) 0.0076* Significant

28 (LOI-2.15761)*(LOI-2.15761)*(LOI-2.15761) 0.8945 Non significant


30 (LOI-2.15761)*(LOI-2.15761)*(IR-24.6315) 0.0060* Significant




34 (LOI-2.15761)*(SO3-2.03871)*(SO3-2.03871) <.0001* Significant

35 (LOI-2.15761)*(SO3-2.03871)*(IR-24.6315) <.0001* Significant

36 (LOI-2.15761)*(SO3-2.03871)*(L10-30.7222) 0.0009* Significant


38 (LOI-2.15761)*(SO3-2.03871)*(L53-88.784) 0.0066* Non significant

39 (LOI-2.15761)*(IR-24.6315)*(IR-24.6315) <.0001* Significant

40 (LOI-2.15761)*(IR-24.6315)*(L10-30.7222) 0.0132* Significant

41 (LOI-2.15761)*(IR-24.6315)*(L30-65.8325) 0.0161* Significant





46 (LOI-2.15761)*(L30-65.8325)*(L30-65.8325) 0.0224* Significant



All single constituents except LOI, IR and L53are found to be significant

towards maintaining quality of ‘7’ day strength.

119

5.3.3.1 Significance of single constituent interactions for 7 day

strength



IR, SO3) are studied as whole model plot and leverage plots, of single

interactions for ’7’ day compressive strength.


The actual and predicted data was plotted as shown in Figure

5.17 for 7 day compressive strength of cement samples. The R2 value

(0.98) indicates good fit between actual values and predicted response.

The horizontal dashed line indicates the mean.

All the constituents were analyzed with single interaction and

the R square found to be feeble. Further interaction effect of two

constituents was analyzed and the R2 value found to be increasing,

with multiple interactions. The above figure 5.17 showing an R2 Value

of 0.98 which makes the regression line looks like a best fit, which

infers the strength development takes place not because of any single

constituent, but interaction of multiple constituents.

120

Figure 5.18: LOI - Leverage Plot


The leverage plot was drawn for Loss on Ignition, as shown in

Figure 5.18, for 7 Day Strength of cement. Loss on Ignition infers

percentage of organic matter in cement mixture.

From the Figure 5.18, the probability value noticed as 0.0001,

as the value is less than 0.05 the parameter LOI can be considered as

a Significant Property. The solid straight line (regression line) is also

seems inclined. This also reveals that LOI was a significant property

within stipulated range.

The coefficient of LOI in equation 5.3, is observed as -16.89,

hence this can be said that the strength decreases with increasing LOI

value for seven day strength.

121

Figure 5.19: SO3 - Leverage Plot


The leverage plot was drawn for sulfur anhydride, as shown in

Figure 5.19, for 7 Day Strength of cement. Sulfur anhydride infers

presence of gypsum in cement mixture.

From the figure 5.19, the probability value noticed as 0.09, as

the value is more than 0.05 the parameter SO3 cannot be considered

as a Significant Property for 7 days compressive strength. The solid

straight line (regression line) is also seems inclined. This also reveals

that SO3 was a significant property within stipulated range.

The coefficient of SO3 in equation 5.3 observed as +15.45; the

positive value can be concluded said that the strength increases with

increasing SO3 value for seven day strength.

122

Figure 5.20: IR - Leverage Plot


The leverage plot was drawn for insoluble residue, as shown in

Figure 5.20, for 7 Day Strength of cement. Insoluble residue infers

presence of flyash in cement mixture.


the value is less than 0.05 the parameter IR can be considered as a

Significant Property for 7 days compressive strength. The dark


that IR was a significant property within stipulated range.

The coefficient of IR in equation 5.3, observed as -1.16; the

negative value can be concluded said that the strength decreases with

increasing IR value for seven day strength.

123




in Figure 5.21, for 7 Day Strength of cement. <10 infers presence of

<10 micron particles in the cement mixture.


the value is more than 0.05 the parameter <10 micron particles i

cannot be considered as a Significant Property for 7 days compressive

strength. The dark solid straight line (regression line) is also seems

inclined. This also reveals that <10 micron particles were a significant

property within stipulated range.

The coefficient of <10 micron particles, in equation 5.3,

observed as 2.62; the positive value can be concluded that the

strength increases with increasing <10 micron particles for seven day

strength.

124




in Figure 5.22, for 7 Day Strength of cement. From the Figure 5.22,

the probability value noticed as 0.45, as the value is more than 0.05

the parameter <30 micron particles may not be considered as a

Significant Property for 7 days compressive strength. The dark solid


that <30 micron particles were a significant property within stipulated

range.

The coefficient of <30 micron particles in equation 5.3, observed

as 1.5; the positive value can be concluded that the strength

increases with increasing <30 micron particles for seven day strength.

125




in Figure 5.23, for 7 Day Strength of cement. From the Figure 5.23,

the probability value noticed as 0.03, as the value is less than 0.05

the parameter <53 micron particles can be considered as a Significant

Property for 7 days compressive strength. The solid straight line

(regression line) is also seems inclined. This also reveals that <53

micron particles were a significant property within stipulated range.

The coefficient of <53 micron particles, in the equation 5.3,

observed as -3.7; the negative value can be concluded that the

strength decreases with increasing <53 micron particles for seven day

strength.

126

5.3.3.2 Significance of multiple constituent interactions for 7

days strength

Response of statistical analysis of 88 samples of physical

constituents (<10, <30 and <53) and chemical constituents (LOI, IR,

SO3) are shown in terms of leverage plots of multiple interactions.

Significance of multiple interactions, and response, is shown in

cluster of figures 5.24.

127




LOI*SO3

Leverage Plot

LOI*IR

Leverage Plot

LOI*L10

Leverage Plot


LOI*SO3*IR

Leverage Plot



128

LOI*L30 Leverage Plot

LOI*L53

Leverage Plot

SO3*SO3

Leverage Plot

SO3*IR

Leverage Plot


LOI*IR*IR

Leverage Plot

LOI*IR*L10

Leverage Plot

LOI*IR*L30

Leverage Plot

129


SO3*L30

Leverage Plot

SO3*L53

Leverage Plot

IR*IR

Leverage Plot





130


IR*L30

Leverage Plot

IR*L53

Leverage Plot

L10*L10

Leverage Plot





131


L10*L53

Leverage Plot

L30*L30

Leverage Plot




L10*L30*IR

Leverage Plot


132




LOI*LOI*IR

Leverage Plot



L30*L30*IR

Leverage Plot


L30*L53*IR

133




Leverage Plot


L53*L53*IR

Leverage Plot

Cluster of Figures 5.24: Response of multiple interactions of physical

and chemical constituents for 7 day compressive strength of cement

samples.

[Note on Multiple Graphical legend of 88 cement samples: Y axis- leverage residuals

of ‘7’ day(s) cured compressive strength of cement; X axis – leverage of

constituent(s) interaction for ‘7’ day(s) compressive strength of cement; horizontal

dotted line-mean line; dark inclined line – regression line; inclined dotted line(s)-

confidence curves; L10-Less than 10µm particles; L30-Less than 30µm particles;

L53-Less than 53µm particles; LOI-loss on ignition; IR-insoluble residue;SO3-

Sulphur Anhydride(SO3)]

134

The constituents, LOI, IR, and <53 found to be significant for 7

day compressive strength, whereas SO3, <10 and <30 found to be non

significant. The significance of multiple constituents is shown in

Table 5.6, and cluster of Figures 5.24.

5.4. Estimation of 28 day Compressive Strength

5.4.1. Effect of physical and chemical constituents on 28 day

strength





36.79 %, and the corresponding 28 day(s) strength values are 55.6

MPa and 60.11 MPa. A decreasing compressive strength values at 28

day(s) curing were observed when % of <10 µm particles increases.

Good values of 28 day(s) compressive strength were observed to be in

the range of 23 % - 33% of <10 µm particles.



MPa and 60.11 MPa. Good values of 28 day(s) compressive strength

were observed to be in the range of 63 % - 73% of <30 µm particles.



135

MPa and 50.75 MPa. Good values of 28 day(s) compressive strength

were observed to be in the range of 80 % - 90% of <53 µm particles.





to 38.9.

28 day(s) strength at minimum LOI value (1.0) found to be 50.5

MPa, which is a moderately a good strength, whereas at maximum

LOI value (4.0) the strength found to be 67.62 MPa, which is also a

good value. Good values of 28 day(s) strength were observed in the

LOI range of 0 % - 2.8%. Though LOI value is high, the other

constituents and parameters are well in the range, which has yielded

excellent strength.

28 day(s) strength at minimum SO3 value (0.45) found to be

54.87 MPa, which is a very good strength, whereas at maximum SO3

value (2.98) the strength found to be 54.06 MPa, which is also a good

strength. With the values of SO3 it can be inferred that not much

impact is observed for seven day(s) strength. 28 day(s) strength values

were observed to be good in SO3 range of 1.5 % to 2.5 %

In general IR value increases, 28 day(s) strength decreasing and

the 28 days strength observed to be good i.e., in the IR range values of

18 % - 27 %. However, there is an exception that at minimum IR value

(15.0) found to be 57.6 MPa, which is a good strength, whereas at

maximum IR value (38.9) the strength found to be 71.16 MPa, which

136

is also very good value. It may be because of more effect of other

parameters on 28 day strength.

137

Table 5.7 : Experimental Results of ‘28’ day compressive strength of


S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles


1 2 1.21 32.6 19.87 49.21 74.52 56.2

2 1.0 1.84 28.7 33.10 69.31 88.46 62.1

3 1.0 2.84 28.6 27.79 62.15 84.49 48.6

4 2.0 1.51 28.8 33.96 70.73 89.24 61.1

5 1.0 1.68 19.8 36.14 73.32 91.36 50.7

6 1.9 2.31 19.1 34.53 71.52 89.62 66.6

7 1.0 2.03 19.7 26.60 66.81 85.22 62.2

8 1.8 1.90 31.0 23.18 54.96 79.42 55.4

9 2.4 1.82 26.1 20.80 51.10 76.36 52.7

10 1.0 1.74 25.1 24.17 56.63 76.72 50.5

11 2.5 2.06 16.6 22.74 54.35 79.00 62.0

12 3.3 2.02 21.4 27.33 61.91 84.50 52.7

13 1.9 1.92 27.0 36.79 74.18 90.70 60.1

14 2.6 2.64 23.7 27.50 71.99 85.50 61.4

15 1.3 1.27 26.5 33.54 74.08 90.73 66.1

16 2.8 1.13 19.8 34.34 72.99 90.38 60.4

17 2.0 2.09 20.4 33.58 73.10 90.37 62.9

18 3.3 1.96 24.7 22.21 53.85 78.83 56.5

19 2.2 1.51 22.1 25.34 66.64 82.20 63.6

20 2.0 1.75 36.7 27.40 61.94 84.52 63.4

21 2.7 1.65 25.1 29.01 64.50 86.15 60.4

22 2.1 1.65 19.1 29.19 64.59 86.14 66.1

23 2.2 1.30 23.0 28.08 63.15 85.35 63.2

24 2.8 1.81 22.1 22.47 53.86 78.55 47.5

25 1.5 1.26 21.5 25.14 63.71 85.98 66.0

26 2.6 2.43 23.9 28.24 62.80 84.90 54.3

27 2.3 2.36 21.8 26.14 66.94 86.43 60.8

28 2.3 2.81 27.4 30.55 66.18 86.91 51.0

29 2.0 1.47 36.0 31.10 66.91 87.31 52.1

30 1.9 2.09 29.7 26.87 60.81 83.67 44.9

31 2.3 2.70 24.9 22.94 54.47 78.97 52.1

32 1.8 2.50 13.9 31.00 72.38 89.14 60.8

33 2.9 2.80 27.5 27.01 63.91 83.66 63.7

34 1.7 2.10 27.5 34.03 70.76 89.24 58.2

35 2.0 2.40 15.5 25.19 58.34 78.01 58.2

36 2.4 2.22 23.5 28.14 69.94 84.43 54.8

37 2.0 2.00 29.3 33.88 70.23 89.08 63.4

38 2.2 2.30 30.6 30.77 66.29 86.90 63.4

39 2.4 1.10 30.4 29.12 64.11 85.71 53.4

40 1.6 1.79 27.0 26.87 63.40 81.12 60.7

41 1.0 2.95 33.5 29.25 64.18 85.70 66.5

42 2.0 1.99 23.8 30.05 65.48 86.52 65.7

43 2.0 1.34 27.0 29.11 64.11 85.71 61.1

44 4.1 2.15 18.2 31.54 67.12 87.29 67.6

138

S.No LOI (%)

SO3 (%)

IR (%)

<10 µm

particles

<30 µm

particles

<53 µm

particles


45 3.2 1.57 38.9 32.93 69.23 88.47 71.1

46 1.4 2.90 31.3 34.13 70.85 89.23 56.2

47 1.5 1.78 31.5 31.74 67.60 87.69 60.7

48 2.5 2.02 34.5 36.14 73.32 91.30 46.9

49 2.3 1.82 34.9 31.16 66.94 87.30 53.4

50 3.0 0.45 21.5 28.79 63.52 85.30 54.8

51 3.0 2.98 19.6 32.36 68.47 88.00 54.0

52 2.9 1.99 23.3 22.88 54.43 78.90 47.5

53 1.2 2.06 23.0 25.20 63.74 84.78 62.7

54 3.0 1.92 36.1 22.50 53.85 78.55 49.9

55 2.2 2.92 23.1 22.64 53.88 78.53 52.4

56 1.5 2.54 30.6 34.21 70.84 89.33 61.2

57 1.5 1.78 18.2 25.97 63.55 82.66 61.7

58 2.5 1.90 33.0 33.44 66.55 86.09 46.9

59 2.3 2.70 24.4 24.59 57.30 78.14 55.8

60 2.2 1.50 19.0 25.75 59.04 82.15 55.6

61 2.2 1.90 26.9 29.49 64.74 86.10 61.5

62 3.0 2.30 20.1 26.62 60.30 83.20 52.2

63 2.9 2.00 24.0 21.08 51.62 76.80 46.4

64 1.7 2.00 28.0 22.13 53.28 78.12 45.0

65 1.5 1.50 20.6 20.82 51.12 76.35 45.8

66 2.4 1.90 24.8 22.71 54.33 79.00 48.7

67 1.8 2.50 22.5 21.26 51.73 76.70 58.3

68 2.3 1.80 31.9 24.23 56.67 80.70 51.5

69 2.7 2.70 27.0 30.75 66.28 86.90 52.8

70 2.0 2.30 31.5 29.32 64.22 85.70 57.4

71 1.4 1.50 19.7 21.55 57.60 77.70 54.8

72 2.1 2.00 18.1 27.75 62.13 84.40 60.8

73 3.0 2.30 23.0 26.38 60.17 83.20 60.0

74 2.3 1.60 24.4 36.14 73.32 91.30 48.3

75 2.3 2.00 30.9 23.89 56.10 80.28 48.3

76 1.2 2.10 25.1 25.97 59.55 76.80 50.5

77 2.0 2.69 22.7 26.76 65.78 83.00 60.6

78 2.3 1.65 27.0 26.42 57.14 84.40 48.6

79 3.0 2.00 21.7 27.76 62.13 84.40 53.4

80 2.4 1.84 23.4 25.70 51.04 76.37 54.3

81 2.4 2.11 15.0 20.80 51.11 76.37 58.2

82 2.5 2.0 15.5 26.42 63.52 81.60 62.5

83 2.5 2.12 27.5 25.77 64.72 84.70 60.5

84 1.9 1.84 31.3 19.28 48.51 74.12 54.9

85 3.2 2.10 22.1 15.59 41.23 66.60 55.8

86 2.1 2.50 24.6 19.84 49.51 75.02 47.8

87 1.8 2.00 19.5 22.89 54.79 79.00 55.3

88 2.4 2.00 23.4 19.88 49.54 75.00 55.5

139

The data in Table 5.7 is used to analyze statistically using statistical software,

to study the effect of individual constituent as well as combined effect on seven

day(s) compressive strength

The equation is developed for 28 day(s) compressive strength as a

function of physical and chemical constituents like Loss On Ignition, Insoluble

Residue, Sulfuric anhydride, <10, <30, and <53 micron particles.

5.4.2. Theoretical model/equation developed for compressive strength of

‘28’ days using JMP statistic analysis

348.3 -6.9*LOI+[-28.6*SO3]+[-0.2*IR+-2.3*L10]+4.8*L30+[-5.0*L53]+[-

19.6*(LOI-2)*(LOI-2)]+15.0*(LOI-2)*(SO3-2.0)+[-1.2*(LOI-2.1)*(IR-24.6)]+[-

13.5*(LOI-2)*(L10-30.7)]+6*(LOI-2)*(L30-65.8)+5.8*(LOI-2)*(L53-88.7)+[-

1.5*(SO3-2)*(SO3-2)]+1.5*(SO3-2)*(IR-24.6)+7.8*(SO3-2.0)*(L10-30.7)+[-

9.6*(SO3-2)*(L30-65.8)]+6.8*(SO3-2)*(L53-88.7)+0.1*(IR-24.6)*(IR-24)+[-2.1*(IR-

24.6)*(L10-30.7)]+1.0*(IR-24.6)*(L30-65.8)+0.4*(IR-24.6)*(L53-88.7)+2.5*(L10-

30.7)*(L10-30.7)+[-2.6*(L10-30.7)*(L30-65.8)]+[-1.5*(L10-30.7)*(L53-88.7)]+[-

0.8*(L30-65.8)*(L30-65.8)]+4.7*(L30-65.8)*(L53-88.7)+[-2.4*(L53-88.7)*(L53-

88.7)]+18.5*(LOI-2.1)*(LOI-2.1)*(LOI-2.1)+13.3*(LOI-2.1)*(LOI-2.1)*(SO3-

2.0)+3.0*(LOI-2.1)*(LOI-2.1)*(IR-24.6)+8.5*(LOI-2.1)*(LOI-2.1)*(L10-30.7)+[-

5.8*(LOI-2.1)*(LOI-2.1)*(L30-65.8)]+0.4*(LOI-2.1)*(LOI-2.1)*(L53-88.7)+1.3*(LOI-

2.1)*(SO3-2.0)

*(SO3-2.0)+0.1*(LOI-2.1)*(SO3-2.0)*(IR-24.6)+0.2*(LOI-2.1)*(SO3-2.0)

*(L10-30.7)+10.8*(LOI-2.1)*(SO3-2.0)*(L30-65.8)+[-13.4*(LOI-2.1)

140

*(SO3-2)*(L53-88.7)]+0.006*(LOI-2.1)*(IR-24.6)*(IR-24.6)+[-0.03*(LOI-2)*(IR-

24.6)*(L10-30.7)]+[-0.5*(LOI-2.1)*(IR-24.6)*(L30-65.8)]+1.1*(LOI-2.1)*(IR-

24.6)*(L53-88.7)+[-8.5*(LOI-2)*(L10-30.7)*(L10-30.7)]+12.4*(LOI-2)*(L10-

30.7)*(L30-65.8)+[-2.0*(LOI-2.1)*(L10-30.7)*(L53-88.7)]+[-2.3*(LOI-2)*(L30-

65.8)*(L30-65.8)]+[-4*(LOI-2.1)*(L30-65.8)*(L53-88.7)]+3.6*(LOI-2)*(L53-

88.7)*(L53-88.7)+[-0.4*(L10-30.7)*(L10-30.7)*(SO3-2)]+0.1*(L10-30.7)*(L10-

30.7)*(IR-24)+2.2*(L10-30.7)*(L30-65.8)*(SO3-2)+0.4*(L10-30.7)*(L30-65.8)*(IR-

24.6)+[-1*(L10-30.7)*(L53-88)*(SO3-2)]+[-0.5*(L10-30.7)*(L53-88.7)*(IR-

24.6)]+4.1*(L30-65.8)*(L30-65.8)*(SO3-2.0)+[-0.1*(L30-65.8)*(L30-65.8)*(IR-

24.6)]+[-13.0*(L30-65.8)*(L53-88.7)*(SO3-2.0)]+[-0.09*(L30-65.8)*(L53-

88.7)*(IR-24.6)]+8.6*(L53-88.7)*(L53-88.7)*(SO3-2.0)+0.3*(L53-88.7)*(L53-

88.7)*(IR-24.6) --- (5.4)

Eq. 5.8 is verified randomly for different sets of experimental values and

the response is very much befitting with approximately 99.5% accuracy. The

percentage of error has been found to be less than 0.5%.


Significance of single constituent as well as interaction of multiple

constituents and response is shown in Table 5.8, developed by JMP statistical

analysis

141

Table 5.8: Significance of single and multiple constituent’s interaction on 28

day compressive strength


1 LOI 0.0037* significant

2 SO3 <.0001* significant

3 IR 0.4609 Non significant




7 (LOI-2.15761)*(LOI-2.15761) <.0001* significant

8 (LOI-2.15761)*(SO3-2.03871) <.0001* significant

9 (LOI-2.15761)*(IR-24.6315) 0.0006* significant


11 (LOI-2.15761)*(L30-65.8325) <.0001* significant



14 (SO3-2.03871)*(IR-24.6315) 0.0005* significant

15 (SO3-2.03871)*(L10-30.7222) 0.0302* significant

16 (SO3-2.03871)*(L30-65.8325) 0.0018* significant

17 (SO3-2.03871)*(L53-88.784) 0.0008* significant

18 (IR-24.6315)*(IR-24.6315) 0.0075* significant

19 (IR-24.6315)*(L10-30.7222) <.0001* significant

20 (IR-24.6315)*(L30-65.8325) 0.0007* significant

21 (IR-24.6315)*(L53-88.784) 0.0107* significant

22 (L10-30.7222)*(L10-30.7222) 0.0002* significant

23 (L10-30.7222)*(L30-65.8325) 0.0002* significant


25 (L30-65.8325)*(L30-65.8325) 0.0063* significant

26 (L30-65.8325)*(L53-88.784) 0.0007* significant

27 (L53-88.784)*(L53-88.784) 0.0185* significant

28 (LOI-2.15761)*(LOI-2.15761)*(LOI-2.15761) <.0001* significant

29 (LOI-2.15761)*(LOI-2.15761)*(SO3-2.03871) <.0001* significant

30 (LOI-2.15761)*(LOI-2.15761)*(IR-24.6315) <.0001* significant




34 (LOI-2.15761)*(SO3-2.03871)*(SO3-2.03871) 0.5213 Non significant

35 (LOI-2.15761)*(SO3-2.03871)*(IR-24.6315) 0.6963 significant

36 (LOI-2.15761)*(SO3-2.03871)*(L10-30.7222) 0.9437 significant



39 (LOI-2.15761)*(IR-24.6315)*(IR-24.6315) 0.8236 Non significant



42 (LOI-2.15761)*(IR-24.6315)*(L53-88.784) <.0001* significant

43 (LOI-2.15761)*(L10-30.7222)*(L10-30.7222) <.0001* significant

44 (LOI-2.15761)*(L10-30.7222)*(L30-65.8325) <.0001* significant





Among all the constituents LOI, SO3, L30 and L53 are found to be significant

towards maintaining ‘28’day compressive strength.

142

5.4.3.1 Significance of single interactions for 28 day strength


constituents (<10, <30, <53 ) as well as chemical constituents (LOI, IR, SO3) are

studied as whole model plot and leverage plots, of single interactions for ’28’

day compressive strength.

Figure 5.25: Response of ‘28’ Day compressive strength using JMP analysis

The actual and predicted data was plotted, and is shown in Figure 5.25,

for 28 Day strength. The R2 value (0.99) indicates good fit between actual

values and predicted response. The horizontal dashed line indicates the mean.

All the constituents were analyzed with single interaction and the R2

found to be feeble. Further interaction effect of two constituents was analyzed

and the R2 value found to be increasing, with multiple interactions.

143

Figure: 5.26: LOI - Leverage Plot


The leverage plot, was drawn for loss on ignition, as shown in Figure

5.26 for 28 Day Strength of cement. From the Figure 5.26, the probability value

noticed as 0.003, as the value is less than 0.05 the parameter LOI can be

considered as a Significant Property for 28 days compressive strength. The

solid straight line (regression line) is also seems inclined. This also reveals that

LOI was a significant property within stipulated range.

The coefficient of LOI in equation 5.24, observed as -6.97; the negative

value can be concluded that the strength decreases with increasing LOI for 28

day strength.

144

Figure 5.27: SO3 - Leverage Plot


The leverage plot was drawn for sulfur anhydride, as shown in Figure

5.27, for 28 Day Strength of cement. Sulfur anhydride infers presence of

gypsum in the cement mixture.

From the Figure 5.27, the probability value noticed as 0.001, as the

value is less than 0.05 the parameter SO3 can be considered as a Significant

Property for 28 days compressive strength. The solid straight line (regression

line) is also seems inclined. This also reveals that SO3 was a significant


The coefficient of SO3, in equation 5.4, observed as -28.6; the negative

value can be concluded that the strength decreases with increasing SO3 for 28

day strength.

145

Fig.ure 5.28: IR - Leverage Plot


The leverage plot for insoluble residue, was drawn as shown in Figure

5.28, for 28 Day Strength of cement. From the Figure 5.28, the probability

value noticed as 0.46, as the value is more than 0.05 the parameter IR cannot

be considered as a Significant Property for 28 days compressive strength. The

solid straight line (regression line) is also seems inclined. This also reveals that

IR was a significant property within stipulated range.

The coefficient of IR in equation 5.4, observed as -0.28; the negative

value can be concluded that the strength decreases with increasing IR value

for 28 day strength.

146

Figure 5.29. L10 - Leverage Plot


The leverage plot, was drawn for <10 micron particles, as shown in

Figure 5.29, for 28 day strength of cement. From the Figure 5.29, the

probability value noticed as 0.1073, as the value is more than 0.05 the

parameter <10 micron particles cannot be considered as a Significant Property

for 28 days compressive strength. The solid straight line (regression line) is also

seems inclined. This also reveals that <10 micron particles were a significant


The coefficient of <10 micron particles, in equation 5.4, observed as -

2.32; the negative value can be concluded that the strength decreases with

increasing <10 micron particles for seven day strength.

147

Figure 5.30:. L30 - Leverage Plot



Figure 5.30, for 28 Day Strength of cement. <28 infers presence of <28 micron

particles in the cement mixture.


value is less than 0.05 the parameter <30 micron particles can be considered

as a Significant Property for 28 days compressive strength. The solid straight

line (regression line) is also seems inclined. This also reveals that <30 micron

particles were a significant property within stipulated range.

The coefficient of <30 micron particles, in equation 5.4, observed as 4.8;

the positive value can be concluded that the strength increases with

increasing <30 micron particles for 28 day strength.

148




Figure 5.31 for 28 Day Strength of cement. <53 infers presence of <53 micron

particles in the cement mixture.


value is less than 0.05 the parameter <53 micron particles can be considered

as a Significant Property for 28 days compressive strength. The solid straight

line (regression line) is also seems inclined. This also reveals that <53 micron

particles were a significant property within stipulated range.

The coefficient of <53 micron particles, in equation 5.4, observed as -

5.01; the negative value can be concluded that the strength decreases with

increasing <53 micron particles for 28 day strength.

149

5.4.3.2. Significance of multiple interactions for 28 day strength

Response of statistical analysis of 88 samples of physical constituents

(<10, <30 and <53) and chemical constituents (LOI, IR, SO3) are shown below

in terms of leverage plots of multiple interactions. Significance of multiple

interactions, and response, is shown in following cluster of figures 5.32.

150




LOI*SO3

Leverage Plot

LOI*IR

Leverage Plot

LOI*L10

Leverage Plot


LOI*SO3*IR

Leverage Plot



151

LOI*L30

Leverage Plot

LOI*L53

Leverage Plot

SO3*SO3

Leverage Plot

SO3*IR

Leverage Plot


LOI*IR*IR

Leverage Plot

LOI*IR*L10

Leverage Plot

LOI*IR*L30

Leverage Plot

152


SO3*L30

Leverage Plot

SO3*L53

Leverage Plot

IR*IR

Leverage Plot




LOI*L10*L53

Leverage Plot

153


IR*L30

Leverage Plot

IR*L53

Leverage Plot

L10*L10

Leverage Plot





154


L10*L53

Leverage Plot

L30*L30

Leverage Plot

L30*L53

Leverage Plot



L10*L30*IR

Leverage Plot


155




LOI*LOI*IR

Leverage Plot



L30*L30*IR

Leverage Plot


156






L53*L53*IR

Leverage Plot

Figures 5.32: Response of multiple interactions of physical and chemical

constituents for 28 day compressive strength of cement

samples.

[Note on Multiple Graphical legend of 88 cement samples: Y axis- leverage residuals of ‘28’

day(s) cured compressive strength of cement; X axis – leverage of constituent(s) interaction for

‘28’ day(s) compressive strength of cement; horizontal dotted line-mean line; dark inclined line

157

– regression line; inclined dotted line(s)-confidence curves; L10-Less than 10µm particles; L30-

Less than 30µm particles; L53-Less than 53µm particles; LOI-loss on ignition; IR-insoluble

residue;SO3-Sulphur Anhydride(SO3)]

The constituents, <30, <53, LOI, and SO3, and found to be significant for

28 day compressive strength, whereas IR, and <10 found to be non significant.

The significance of multiple constituents is shown in Table 5.8, and cluster of

Figures 5.32.

Among all the significant values of JMP output, <53 µm particles were

found to be highly significant in maintaining the overall quality of cement.

Further studies have been done basing on the < 53 µm particles.

From the experimental and JMP statistical analysis the effect of

constituents on 1, 3, 7 and 28 day compressive strength of cement, are

observed as follows:

1 day strength: Higher percentages of <10 µm particles are yielding

higher 1 day strength, which is matching with the established research [12,

149] irrespective of other parameters. It was also observed, if other

constituents are little more than the stipulated values, the fineness is

promoting towards higher strengths.

3 day strength : <10 µm particles are also yielding higher 3 day

strength, which is matching with the established research [12,149] irrespective

of other parameters. It was also observed, that higher 3 days strengths were

found, where all the constituents are in the stipulated range.

158

7 day strength: No specific constituent is directly involved in obtaining

higher strengths, however stipulated values are observed to obtain good

strengths.

28 day strength: Higher percentages of <53 micron particles are yielding

to be good strength, which is matching with reported research [12,146],

however stipulated values are observed to maintain good quality strength.

In continuation to the research work done in the area of effect of particle

size, and distribution of particle size [12,146], it is intended to find specific

range of constituents, responsible for maintaining good strength.

5.5. Estimation of Physical parameters of cement samples and their

relevance to quality

Physical parameters or reference parameters, like bulk density (BD),

tapped density (TD), Husner’s ratio, and surface area are estimated for all the

88 cement samples and reported in Table 5.9. Basically these parameters

reflect the physical and chemical constituents present in the cement. Further,

1, 3, 7 and 28 strength values are also re-written in the Table 5.9 to study the

effect of physical parameters on strength.

Bulk density values observed to be in the range of 0.72 g/cc to 1.13

g/cc. It was observed lower BD values, yields lower strength, and higher BD

values also yields lower strength. It may be attributed fact that a higher bulk

density value indicates higher percentage of iron, which is undesired substance

in the cement. A range of BD values found to yield good strength i.e 0.75 g/cc

159

to 0.85 g/cc, highest compressive strength values(s) were observed at bulk

density 0.85 g/cc

Tapped density (TD) values observed to be in the range of 0.88 g/cc to

1.29 g/cc. It was observed that, lower TD values, yields lower strength and

higher TD values also yields lower strength. Further, it may be observed from

the Table 5.9, that, a good strength is found for tapped density values between

1.10 g/cc to 1.25 g/cc and highest compressive strength was observed at

tapped density value of 1.10 g/cc.

Surface area observed to be in the range of 2739.6 m2/kg to 5949

m2/kg. The values of compressive strength(s) observed to be increasing as the

surface area increases, however in few cases reverse values were observed,

which may be because of higher percentage of LOI. Good strength values are

observed to be in the range of 3500 m2/kg to 4500 m2/kg of surface area.

Table 5.9: Physical parameters and corresponding compressive strength(s) of

cement samples

S.No Bulk

Density

Tapped

Density

Huasner’s

Ratio

Blains

(m2/kg)

1 day

Strength

(MPa)

3 days

Strength

(MPa)

7 days

Strength

(MPa)

28 days

Strength

(MPa)

1 0.79 1.10 1.38 4124.5 6.58 21.58 32.75 56.2

2 0.78 1.22 1.57 5210.7 13.80 27.87 32.88 62.1

3 0.86 1.18 1.38 4449.8 8.43 23.41 44.55 48.6

4 0.85 1.19 1.41 4087.3 14.61 28.15 35.32 61.1

5 0.88 1.22 1.45 4236.8 14.311 33.85 34.30 50.7

6 0.87 1.23 1.42 3896.7 11.16 29.29 31.81 66.6

7 0.96 1.23 1.28 4486.1 10.35 21.58 34.91 62.2

8 0.94 1.20 1.28 4109.2 12.89 30.92 39.38 55.4

9 0.89 1.12 1.23 3271.3 10.35 19.6 35.93 54.6

10 0.77 1.16 1.5 3973.3 10.55 23.24 30.17 50.5

11 0.90 1.13 1.26 3651.8 10.55 22.53 27.54 59.8

12 0.86 1.26 1.46 3281.8 11.77 25.24 36.17 52.7

13 0.84 1.21 1.45 4054.3 21.11 34.172 37.70 60.1

14 0.78 1.25 1.46 3645.5 14.61 30.179 34.50 61.4

20007000

160

15 0.88 1.16 1.32 3643.4 16.44 34.307 39.50 66.1

16 0.84 1.26 1.49 3586.2 11.77 32.615 35.30 60.4

17 0.82 1.25 1.53 3683.0 8.90 33.3 42.30 62.9

18 1.03 1.29 1.25 2739.6 10.50 30.585 33.16 56.5

19 0.92 1.27 1.39 3501.6 7.50 26.5 41.30 63.6

20 0.80 1.25 1.56 3632.9 14.5 31.1 44.30 63.4

21 0.80 1.27 1.59 3505.6 10.3 27.0 34.80 60.4

22 0.82 1.28 1.56 4023.5 12.7 35.0 44.50 66.4

23 0.82 1.29 1.49 3681.5 14.9 34.7 45.40 63.2

24 1.06 1.19 1.12 3899.6 15.10 29.5 36.94 47.1

25 0.84 1.21 1.45 4145.7 16.64 30.85 49.73 66.0

26 0.86 1.04 1.21 4554.1 8.40 24.9 33.35 54.3

27 0.85 1.19 1.41 3980.6 14.30 28.29 38.63 60.0

28 0.89 1.09 1.23 4295.4 12.99 28.55 40.60 51.0

29 0.95 1.14 1.19 4349.1 11.77 31.32 42.22 51.0

30 0.91 1.16 1.27 4233.4 7.05 25.51 34.17 44.9

31 0.89 1.18 1.32 3820.7 11.0 21.8 33.90 52.1 32 0.88 1.21 1.37 4413.7 16.44 37.21 48.04 60.8

33 0.85 1.20 1.41 4048.3 14.31 32.75 47.36 63.7

34 0.89 1.13 1.23 3467.6 12.78 30.24 39.33 59.4

35 0.84 1.32 1.57 3238.3 17.66 33.76 41.95 58.2

36 0.86 1.20 1.4 3741.0 13.2 29.9 36.63 62.0

37 0.77 1.17 1.5 3652.4 13.8 25.9 43.70 64.1

38 0.85 1.19 1.41 4180.4 14.6 27.4 40.60 64.1

39 0.93 1.21 1.31 3474.9 14.3 28.3 37.90 53.3

40 0.85 1.15 1.35 4781.9 9.65 29.02 37.69 60.7

41 0.83 1.19 1.36 4833.6 10.74 28.82 47.09 66.5

42 0.84 1.25 1.49 4254.2 10.41 34.23 47.90 65.7

43 0.82 1.20 1.47 4323.4 8.92 25.98 35.79 60.0

44 0.77 1.17 1.5 5949.0 11.36 41.75 50.00 67.6

45 0.78 1.22 1.56 4650.4 20.6 34.91 48.72 71.1

46 1.06 1.21 1.14 4571.1 13.9 31.66 42.01 56.2

47 0.85 1.16 1.37 4617.8 17.46 34.23 44.52 60.5

48 1.04 1.20 1.16 4260.2 11.46 25.1 35.86 46.9

49 0.95 1.19 1.25 4520.9 18.25 32.68 42.35 53.4

50 1 1.10 1.1 4928.9 17.25 35.79 48.58 54.8

51 1.02 1.10 1.08 4777.5 17.15 35.65 45.26 54.0

52 1.13 1.24 1.1 4267.9 8.83 22.32 32.00 47.5

53 0.96 1.23 1.28 4459.1 14.91 33.22 49.19 62.7

54 1.06 1.13 1.07 4021.3 12.17 26.38 34.78 49.9

55 1.12 1.22 1.09 4731.6 11.77 26.38 35.76 52.4

56 0.92 1.19 1.27 4772.8 15.52 33.89 46.48 61.2

57 0.85 1.16 1.37 3917.7 17.05 38.49 49.83 61.7

58 0.72 1.04 1.45 4840.6 10.1 28.55 33.15 46.8

59 0.81 1.19 1.46 4316.9 9.33 27.06 38.49 55.8

60 0.77 0.96 1.26 4502.4 12.07 33.49 43.10 55.0

61 0.73 1.04 1.42 4107.7 17.86 32.2 41.74 61.5

62 0.74 1.03 1.40 4876.0 16.54 33.26 40.79 52.2

63 0.92 1.09 1.19 3305.5 7.74 24.69 30.65 46.4

64 0.74 0.88 1.23 3803.8 7.66 23.00 26.85 45.6

65 0.87 1.07 1.23 3391.7 10.83 25.84 33.02 45.8

66 0.78 1.07 1.37 3329.8 10.18 26.45 31.86 48.7

67 0.94 1.23 1.31 3987.6 9.87 31.46 42.08 58.3

161

68 0.76 1 1.31 4296.6 10.59 24.66 34.18 51.5

69 0.85 1.1 1.29 4927.7 11.26 24.27 32.86 52.8

70 0.77 1.07 1.4 5185.6 15.63 31.12 42.14 57.4

71 0.79 1.16 1.37 4111.2 16.13 37.59 46.20 54.8

72 0.83 1.11 1.34 4367.8 15.79 30.96 41.22 61.6

73 0.85 1.05 1.23 3976.2 9.75 26.86 39.92 55.8

74 0.92 1.06 1.15 5406.7 8.80 24.46 37.67 48.3

75 0.84 1.05 1.25 4320.1 11.13 27.49 34.23 49.5

76 0.79 1.09 1.38 3897.6 11.37 27.18 31.21 50.3

77 0.88 1.10 1.25 3904.4 8.52 23.52 32.69 60.6

78 0.85 0.87 1.02 3490.1 14.51 27.87 37.88 50.3

79 0.85 0.95 1.11 3386.0 10.86 25.41 33.62 53.4

80 0.85 1.00 1.18 3127.7 9.7 19.88 31.56 54.1

81 0.85 0.85 1.00 3418.3 15.83 30.24 38.70 57.6

82 0.85 1.10 1.29 3659.9 23.43 41.54 51.49 62.5

83 0.85 1.16 1.37 3520.5 19 27.90 39.71 60.5

84 0.85 1.02 1.20 3099.9 13.29 28.14 39.11 54.9

85 0.85 0.89 1.05 3230.3 8.47 22.39 34.57 55.6

86 0.85 0.87 1.02 3060.1 9.51 25.84 32.58 47.8

87 0.85 0.94 1.11 3440.4 10.11 22.32 30.51 55.3

88 0.85 0.98 1.15 3060.1 10.17 25.91 37.89 55.5

Husners ratio values observed to be in the range of 1.23 to 1.56. It was

observed that lower HR values, yields lower one day strength, and higher HR

values also yields higher one day strength. Higher HR value also infers higher

fineness, and similar values were observed [146].

162

5.6. Range of Variables for quality cement: Proposal of hypothesis

The results reported in Table 5.1, 5.3, 5.5, and 5.7 reveals that the 1, 3,

7 and 28 day strength depends on the physical and chemical constituents.

Further, section 5.5 indicates that these chemical and physical consitutens can

be studied interms of physical properties (bulk density, tap density, Husners

ratio, surface area) or in other words the physical properties will have influence

the quality of cement. In addition to this there is range of variables to get

better quality cement. For example statistical analysis of data using JMP

software (section 5.1-5.4), it is found that particle size constituents (<10, <30,

<53) are significant in maintaining good quality of cement. Amongst the three

particle size constituents the significant effect of 53 micron is found to be more.

Hence 53 micron particle is considered as a critical constituent. Therefore, by

careful observation of data in the Tables 5.1, 5.3, 5.5, 5.7 and 5.9, there is

range of values of physical and chemical constituents found to yield good

quality and the range is reported in the Table 5.10

Table 5.10: Specific range of constituents and parameters

S.No Parameter / constituent Range

1 Bulk density 0.75-0.85 g/cc

2 Tapped density 1.10-1.25 g/cc

3 Husners Ratio(flowability) 1.25-1.50

4 Loss on ignition(LOI) 0-2.8 %

5 SO3 1.5-2.5 %

6 Insoluble Residue 18-27 %

7 <10 23-33 %

8 <30 63-73 %

9 <53 80-90 %

10 Blaines 3500-4700 m2/Kg

163

It is also observed from experimental studies that, by adjusting 53 µm

particles, entire constituent percentages are being modified. This infers that,

low quality cement can be promoted to high quality by re- adjusting the

particle size distribution. This in turn maintains the stipulated parameters as

mentioned in Table 5.10. In the next session, such feeble quality of cement

samples are picked up and modified the particle size distribution, by adding 53

µm particles which is critical size. Further, one may hypothesize that

Out of 10 constituents, if 6 of the constituents falls in the range given in

Table 5.10, the cement may said to be satisfactory cement.


Table 5.10, the cement may said to be good cement.


Table 5.10, the cement may said to be very good cement.


Table 5.10, the cement may said to be excellent cement.

Out of 10 constituents, all constituents falls in the range given in Table

5.10, the cement may said to be outstanding cement.

164

The above 10 constituents can be condensed and assessed by measuring

D85 particles, which qualifies all the above mentioned prerequisites, as

percentage of <53 micron particles required is 85. The quality of any cement

can be enhanced by modifying the particle size distribution and meeting the

above mentioned range of constituents and satisfactory quality cement can be

transformed to outstanding quality cement.

5.7. Validation of hypothesis

To validate significant constituent observed in JMP software i.e the 53

micron size constituents and their effectiveness, another set of ten samples

were procured from market and analyzed for physical and chemical

constituents. The obtained data is reported in Table 5.11. It may be observed

from Table 5.11 that three samples A, C, and G found to be feeble in quality

which is measured interms of strength. Further, it may observed from Table

5.12 that the A, C & G samples are having <53 particles of 72, 76 and 94%,

respectively and the remaining samples are having <53 particles in the range of

80-90 %. As mentioned earlier <53 particles are crucial parameter for getting

good quality cement and the range should be in the order of 80-90 %.

165

Table 5.11: Post JMP analysis- analysis of cement samples

Parameter A B C D E F G H I J

B.D 0.89 0.81 0.91 0.77 0.81 0.84 0.72 0.75 0.88 0.82

T.D 1.06 1.15 1.09 1.10 1.14 1.15 1.19 1.0 1.20 1.20

H.R 1.19 1.41 1.19 1.42 1.40 1.36 1.65 1.33 1.36 1.46

LOI 2.04 2.51 1.90 1.80 2.86 1.58 1.87 2.74 1.65 2.63

IR 22 29 27 23 31 22 31 18 24 29

SO3 1.72 1.89 1.71 2.14 1.97 2.46 2.1 3.1 2.5 2.2

<10 23 27 21 28 27 31 39 27 29 26

<30 58 65 56 66 65 69 78 64 67 66

<53 72 82 76 84 86 83 94 81 88 81

Blaines 3416 3976 3323 4268 4532 4186 4963 3785 3665 3612

1 Day 22.4 25.2 24.7 26.9 23.5 25.1 24.3 29.7 31.3 30.4

3 Day 38.2 32.5 35.2 38.4 36.8 38 34.3 38.6 40.8 41.3

7 Day 45.3 45.2 43.1 46.5 44.9 45.3 45.2 49.1 51.1 51.2

28 Day 56.4 60.6 57.8 62.8 62.3 63.1 55.4 63.2 62.7 63.4

The A, C, and G samples were subjected to redistribution of particles by

adjusting -53 micron particles and in turn bringing the samples in the

suggested range of 80-90% of <53 particles. These modified samples are named

as A*, C* and G*. The compressive strength, chemical physical & chemical

constituent and physical parameters of these modified samples are measured

and reported in the Table 5.12 along with original sample values. It may

observe from the Table 5.12 that the compress strength of modified samples is

around 10% higher than original samples. Further, it may also observed from

the Table 5.12 that by adjusting <53 particles in the range of 80-90%, 8-9 of

the parameters mentioned in the Table 5.10 are meeting, whereas original

samples are meeting 5-6 parameters only. Therefore, the study clearly indicates

that any satisfactory cement may be transformed to excellent quality cement

just by adjusting <53 particles.

166

Table 5.12: Physical/chemical constituents & strength of original and

modified cement samples

Parameter A C G A* C* G*

B.D 0.89 0.91 0.72 0.84 0.85 0.78

T.D 1.06 1.09 1.19 1.15 1.13 1.20

H.R 1.19 1.19 1.65 1.43 1.49 1.36

LOI 2.04 1.90 1.87 2.9 2.6 2.45

IR 22 27 31 24 29 32

SO3 1.72 1.71 2.1 1.90 2.23 2.65

<10 23 21 39 28 27 29

<30 58 56 78 66 68 67

<53 72 76 94 82 81 84

Blaines 3416 3323 4963 3864 4021 4231

1 Day 22.4 24.7 24.3 24.64 26.76 25.42

3 Day 38.2 35.2 34.3 40.43 36.76 36.65

7 Day 45.3 43.1 45.2 46.49 44.65 47.65

28 Day 56.4 57.8 55.4 61.98 63.87 62.87

To re-confirm the validated results of Table 5.12, the same samples (A, C

and G) were procured from market after a span of 45 days, and were labeled as

A1, C1 and G1. All samples were redistributed based on 53 micron particle.

The redistributed values were labeled as A1*, C1* and G1*. The obtained

results are reported in Table 5.13 and results were matching with earlier

values given in the Table 5.12.

167

Table 5.13: Re-Validation of feeble samples

Parameter A1 C1 G1 A1* C1* G1*

B.D 0.92 0.90 0.70 0.85 0.82 0.78

T.D 1.06 1.09 1.16 1.17 1.15 1.19

H.R 1.21 1.19 1.68 1.33 1.51 1.41

LOI 2.21 1.98 1.68 2.88 2.72 2.5

IR 21 28 29 23 29 31

SO3 1.77 1.79 2.4 2.01 2.32 2.55

<10 24 21 38 29 28 30

<30 57 56 77 68 66 69

<53 74 73 91 81 83 85

Blaines 3343 3421 4838 3743 4076 4298

1 Day 22.9 25.2 22.3 24.64 26.76 25.42

3 Day 37.54 34.76 34.8 39.53 37.87 36.12

7 Day 44.32 44.18 45.1 47.63 45.42 48.60

28 Day 55.48 56.52 53.62 62.58 63.36 64.1

Finally one may conclude that <53 particles are crucial parameter for

very good cement.

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