Workability For Concrete Specimens Finance Essay

July 15, 2017 General Studies

The consequences of compressive strength for concrete reinforced by adding 2.5 of wastes cigarette butts ( W.C.B ) by volume are present in this chapter. In this survey, three type of blending concrete mixes will be designed for changeless class 30 but utilizing different per centum of H2O to cement ratio ( w/c ) . The w/c is 0.55, 0.60 and 0.65 were conducted.

In this present survey, there are effort in utilize of coffin nail butts in discharged clay bricks conducted by Aeslina et al. , 2010. Four variables of blending are utilizing different per centums of coffin nail butts which are 0 % , 2.5 % , 5.0 % and 10.0 % by weight. The compressive strength trial shows that the strength decreases with the increasing proportion of coffin nail butts. The compressive strength trial determines the maximal burden that the specimen could sustained over transverse sectional country at ages 134 yearss.

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Workability for Concrete Specimens

Workability trial include slump trial, vebe trial and packing factor trial. In this survey, each of the trials was conducted to prove three types of mix which have w/c 0.55, w/c 0.60 and w/c 0.65 and a control mix of w/c 0.55. The consequences of all the trials were tabulated in Table 4.1, Table 4.2 and Table 4.3 severally.

Slump Test for Concrete Specimens

Table 4.1 shows the consequence of slack trial for three types of different w/c specimens with changeless sum of W.C.B and a control mix specimen that without the W.C.B contents. Control mix specimen gave a 70mm of slack which is the lowest slack value comparison to the other specimens that assorted with W.C.B. For specimens with w/c 0.55, w/c 0.60 and w/c 0.65, their slack values were 85mm, 120mm and 150mm severally. It was shown that the w/c of 0.65 has the highest slack and highest workability in this survey. Figure 4.1 illustrated the consequence of slack trial for different mix specimens.

Table 4.1: Consequences of Slump Test for Different Mix Specimens

Water to Cement Ratio ( w/c )

Slump ( millimeter )

Control Mix

70

0.55

85

0.60

120

0.65

150

Figure 4.1: Consequences of Slump Test for Different Mix Specimens

Vebe Test for Concrete Specimens

Table 4.2 shows the consequences of Vebe trial for three types of different w/c specimens with changeless sum of W.C.B and a control mix specimen without the W.C.B content. There was 3.20seconds of Vebe obtained for the control mix specimen, which is the highest among other specimens. For w/c 0.55, there is 3.05s while for w/c 0.60, 2.70s was obtained. Specimens with w/c of 0.65 has the lowest Vebe which has merely 2.25s which has the highest workability. Figure 4.2 illustrated the consequence of Vebe trial for different mix specimens.

Table 4.2: Consequences of Vebe Test for Different Mix Specimens

Water to Cement Ratio ( w/c )

Vebe ( s )

Control Mix

3.20

0.55

3.05

0.60

2.70

0.65

2.25

Figure 4.2: Consequences of Vebe Test for Different Mix Specimens

Compacting Factor Test for Concrete Specimens

Table 4.3 shows the consequences of packing factor for three types of different w/c specimens with changeless sum of W.C.B and a control mix specimen without the W.C.B content. It was clearly shown that control mix has low packing factor due to the big per centum of divergence 0.957 % that is from 16.3kg to 15.6kg. Specimens with w/c 0.65 gave the lowest divergence 0.994 % which is from 16.3kg to 16.2kg, hence it has highest packing factor. For specimens of w/c 0.55 and w/c 0.60, their divergences were 0.982 % and 0.988 % severally. Figure 4.3 illustrated the consequence of packing factor trial for different mix specimens.

Table 4.3: Consequences of Compacting Factor for Different Mix Specimens

Water to Cement Ratio ( w/c )

Weight ( kilogram )

Percentage of Compacting %

Before

After

Control Mix

16.3

15.6

0.957

0.55

16.7

16.4

0.982

0.60

16.6

16.4

0.988

0.65

16.3

16.2

0.994

Figure 4.3: Consequences of Compacting Factor for Different Mix Specimens

Compressive Strength for Concrete Specimens

The compressive strength trial is carried out to find the strength of the concrete regular hexahedron with extra of waste coffin nail butts ( W.C.B ) at ages 7, 14 and 28 yearss. The compressive strength was calculated utilizing Equation 3.2 as mentioned in chapter 3. Three different mix of H2O cement ratio ( w/c ) were considered viz. as Mix A ( w/c 0.55 ) , Mix B ( w/c 0.60 ) and Mix C ( w/c 0.65 ) . A control mix with w/c 0.55 and no coffin nail butt content was tested in order to compare the consequences from the specimens with Mix ( A, B and C ) .

Consequence of Water to Cement Ratio on Compressive Strength for Concrete Due to Different Mix at Ages 7 yearss

Table 4.4 shows the consequence of compressive strength for different w/c mix with add-on of 2.5 % of waste coffin nail butts ( W.C.B ) by volume at ages of 7 yearss. Figure 4.4 illustrated that the compressive strength of concrete due to different mix at age 7 yearss. The consequences show that the compressive strength was diminishing with the increasing of H2O cement ratio ( w/c ) . Compressive strength of 14.53MPa was obtained for w/c 0.55, 14.51MPa for w/c 0.60 and 10.91MPa for w/c 0.65 while the control mix achieved 19.00MPa. It is noticed that the compressive strength for w/c 0.55 is 14.53MPa which is lessenings by 23.5 % compared to the compressive strength of control mix. For w/c 0.60, it decreases by 23.6 % while for w/c 0.65, it decreases by 42.6 % .

Table 4.4: Compressive Strength for Concrete Due to Different Mix at Ages 7 yearss

Water to Cement Ratio ( w/c )

Compressive Strength ( MPa )

1

2

3

Average

Control Mix

17.99

19.49

19.52

19.00

0.55

14.31

15.01

14.17

14.53

0.60

14.38

14.65

14.51

14.51

0.65

10.08

11.32

11.34

10.91

Figure 4.4: Compressive Strength for Concrete Due to Different Mix at Ages 7 yearss

Consequence of Water to Cement Ratio on Compressive Strength for Concrete Due to Different Mix at Ages 14 yearss

Table 4.5 shows the consequence of compressive strength for different w/c mix with add-on of 2.5 % of waste coffin nail butts ( W.C.B ) by volume at ages of 14 yearss. Figure 4.5 illustrated that the compressive strength of concrete due to different mix at age 14 yearss. The consequences show that the compressive strength was diminishing with the increasing of H2O cement ratio ( w/c ) . Compressive strength of 17.55MPa was obtained for w/c 0.55, 17.16MPa for w/c 0.60 and 11.81MPa for w/c 0.65 while the control mix achieved 20.37MPa. It is noticed that the compressive strength for w/c 0.55 is 17.55MPa which is lessenings by 13.8 % compared to the compressive strength of control mix. For w/c 0.60, it decreases by 15.8 % while for w/c 0.65, it decreases by 42.0 % .

Table 4.5: Compressive Strength for Concrete Due to Different Mix at Ages 14 yearss

Water to Cement Ratio ( w/c )

Compressive Strength ( MPa )

1

2

3

Average

Control Mix

21.22

20.38

19.52

20.37

0.55

19.61

16.55

16.50

17.55

0.60

19.76

15.82

15.89

17.16

0.65

11.26

12.35

11.82

11.81

Figure 4.5: Compressive Strength for Concrete Due to Different Mix at Ages 14 yearss

Consequence of Water to Cement Ratio on Compressive Strength for Concrete Due to Different Mix at Ages 28 yearss

Table 4.6 shows the consequence of compressive strength for different w/c mix with add-on of 2.5 % of waste coffin nail butts ( W.C.B ) by volume at ages of 28 yearss. Figure 4.6 illustrated that the compressive strength of concrete due to different mix at age 28 yearss. The consequences show that the compressive strength was diminishing with the increasing of H2O cement ratio ( w/c ) . Compressive strength of 19.11MPa was obtained for w/c 0.55, 18.07MPa for w/c 0.60 and 15.47MPa for w/c 0.65 while the control mix achieved 22.42MPa. It is noticed that the compressive strength for w/c 0.55 is 17.55MPa which is lessenings by 14.7 % compared to the compressive strength of control mix. For w/c 0.60, it decreases by 19.4 % while for w/c 0.65, it decreases by 31.0 % .

Table 4.6: Compressive Strength for Concrete Due to Different Mix at Ages 28 yearss

Water to Cement Ratio ( w/c )

Compressive Strength ( MPa )

1

2

3

Average

Control Mix

23.00

23.60

20.67

22.42

0.55

19.19

19.17

18.98

19.11

0.60

17.49

17.52

19.19

18.07

0.65

15.42

15.47

15.51

15.47

Figure 4.6: Compressive Strength for Concrete Due to Different Mix at Ages 28 yearss

t-Test Analysis for Compressive Strength at Ages 28 yearss

The sum-up of t-test analysis for control mix is presented in Table 4.7. Since the void hypothesis stated that there was no statistically important different between control mix and w/c 0.55, the analysis consequence failed to reject the void hypothesis as indicated by: tstat & A ; lt ; tcrit ( 3.69 & A ; lt ; 4.30 ) and P & A ; gt ; & A ; Icirc ; ± ( 0.07 & A ; gt ; 0.05 ) . Therefore it can be concluded, at 95 % assurance degree, there was no important difference between control mix and the specimen which w/c is 0.55 as the alternate beginning stuff.

Table 4.7: t-Test: Two-Sample Assuming Unequal Variances

W/C

C/M

0.55

Mean

22.42333

19.11333

Discrepancy

2.395633

0.013433

Observations

3

3

Hypothesized Average Difference

0

df

2

T Stat

3.693722

P ( T & A ; lt ; =t ) one-tail

0.033055

t Critical one-tail

2.919986

P ( T & A ; lt ; =t ) two-tail

0.066109

t Critical two-tail

4.302653

& A ; Acirc ;

x

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