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ADDING CALCIUM INFLUENCE ON COMPRESSIVE STRENGTH OF MORTAR WITH DIFFERENT CEMENT VARIATIONS

 

Khairil Yanuar, Abdul Hafizh Ihsani, Faryanto Effendi, Muhammad Suhaimi, Ruspiansyah

Politeknik Negeri Banjarmasin, Indonesia

Email: [email protected], [email protected], [email protected], [email protected], [email protected]

 

 

Abstract

 

 

 

Article Information:

Received

Revised

Accepted

 

 

Keywords:

Compressive strength; Mixed proportions;Cement variations

Mortar is a mixture of binder and sand in a certain ratio, the binder is cement and lime. This test aims to determine the results of the compressive strength of mortar aged 3,7,14, and 28 days on variations of cement and lime mixture. The fine aggregate used in this test is Barito Sand which is included in zone 2. With the composition of the mixture used is 1 pc : 5 ps for cement and sand, the mixture used for cement, lime and sand is 1 pc : 1_4^1kp : 5 ps. From the results of this study with the same mixture proportions, the compressive strength for the variation of cement conch (PCC) = 7.40 MPa, the variation of cement gresik (PPC) = 10.41 MPa, the variation of cement conch with a mixture of lime = 4.54 MPa and strong Press the mortar for the variation of Gresik cement with a mixture of lime = 7.90 MPa. It can be concluded that the compressive strength of mortar for cement conch with a mixture of lime is higher than the variation of cement conch, gresik and conch with a mixture of lime.

 

Introduction

Mortar is a mortar consisting of fine aggregate (sand), binder (clay, lime, portland cement) and water. The function of mortar is as a binding matrix for the constituent parts of a construction, both structural and non-structural. The use of mortar for construction of a structural nature, such as masonry mortar for foundation structures, while non-structural ones, such as masonry mortar for infill walls.

Considering the importance of mortar as part of the load-bearing construction, the use of mortar must comply with the standard specification of SNI-03-6825-2002. The mortar specification standard refers to its compressive strength, namely the mortar's ability to accept loads. Similar to concrete, the compressive strength of mortar is influenced by several factors, including water-cement and density factors, type of cement, amount of cement, aggregate properties and also the age of the mortar. , because usually the mortar will be loaded with a construction on it before reaching the age of 28 days. Therefore, compressive strength tests at the stages of mortar hardening age, namely, 3, 7, 14, and 28 days need to be carried out to control the quality of the compressive strength to be as expected, which is not less than the compressive strength required in the bestek. The evaluation results are used to determine whether the compressive strength of the mortar meets the requirements or not. So a value that can be used to express the relationship between the compressive strength at the beginning of the mortar age and the compressive strength of the mortar characteristics is needed.

 

Method

1. Making Test Items

The manufacture of mortar specimens with variations to obtain appropriate results, respectively in each mortar composition and the proportion of mortar mixture in each manufacture of test specimens is made based on SNI 03-6882-2002.

 

Table 1

Number of Test Objects For Mortar (Cube 5 cm x 5 cm)

No

Sample Name And Composition

Mortar Age

Number of Test Items

3 Days

7 Days

14 Days

28 Days

1

Semen Conch 1Sp : 5 Ps

3

3

3

6

15

2

Semen Gresik 1 Sp : 5 Ps

3

3

3

6

15

3

Semen Conch + Kapur

1 Sp: Kp : 5 Ps

3

3

3

6

15

4

Semen Gresik + Kapur

1 Sp: Kp : 5 Ps

3

3

3

6

15

Total

60

 

1. Flowchart

In this study, several work steps were carried out as listed in the flow chart of the research stages in Figure 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


No

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Figure 1

Research Method Flowchart

Results and Discussion

1. Fine Aggregate Test Results (Barito Sand)

The fine aggregate used is barito sand, by testing the mud content, organic matter content, specific gravity, absorption, bulk density, water content, sieve analysis, the results of the fine aggregate test (barito sand) can be seen in table 2.

 

Table 2

Fine Aggregate Test Results (Barito Sand)

No

Kinds of Inspection

Barito Sand

Specification

Standard/Reference

Result

SII 0052-80

1

Sludge levels

%

SNI 03-4142-1996

0,91%

Max. 5%

 

 

2

Organic Substance Level

SNI 03-2816-1992

No. 4

Color Standard No. 2

3

SSD Specific Gravity

SNI 03-1870-1990

2.66 gr

Min. 2.5

4

Absorption

%

SNI 03-1870-1990

0,45%

Max. 3%

5

Water content

%

SNI 03-1971-1990

2,98%

 

6

Grading Arrangement Aggregate :

 

 

 

Zona II

 

No.4

SNI 03-1968-

100

90-100

 

No.8

 1990

 

87,66

85-100

 

No.16

 

 

80,42

75-100

 

No.30

 

 

52,20

60-79

 

No.50

 

 

16,31

12-40

 

No.100

 

 

 

 

 

1,69

0-10

 

From the test results it can be concluded that fine aggregate (barito sand) is included in SII 0052-80 and can be used for mortar mixtures.

 

1. Cement Test Results

In the cement testing carried out, there were 2 types of 3 types of cement, namely Gresik cement (PPC), Tonasa cement and Tiga Roda (PCC). The test results of the three cements can be seen in table 2. to table 3.

 

Table 3

Semen Gresik (PPC) Test Results

No

Kinds of Inspection

Granulated Cement (PPC)

Specification

Reference Standard

Result

1

Specific gravity

AASHTO T-133-74

3,07

-

2

Subtlety

AASHTO T-128-76

- stuck filter No.100

0,12%

-

- stuck filter No.200

15,44%

-

3

Consistency

AASHTO T.19-74

24,67%

-

4

Binding Time

AASTHO-13174

SNI 15-0302-2004

- Beginning of Bonding

125 Minutes

Min. 45 Minutes

- End of Binding

195 Minutes

Maks. 7 O'clock

 

Table 4

Cement Conch Test Results (PCC)

No

Kinds of Inspection

Granulated Cement (PPC)

Specification

Reference Standard

Result

1

Specific gravity

AASHTO T-133-74

3,23

-

2

Subtlety

AASHTO T-128-76

- stuck filter No.100

0%

-

- stuck filter No.200

1,76%

-

3

Consistency

AASHTO T.19-74

25,67%

-

4

Binding Time

AASTHO-13174

SNI 15-7064-2004

- Beginning of Bonding

129 Minutes

Min. 45 Minutes

- End of Binding

210 Minutes

Maks. 375 Minutes

 

Table 5

Chalk Test Results

No

Kinds of Inspection

Three Wheel Cement (PCC)

Reference Standard

Result

1

Specific gravity

AASHTO T-133-74

3,03

2

Subtlety

AASHTO T-128-76

- retained filterNo.100

3,72

- stuck filter No.200

22,7

 

Table 6

Cement Conch Fastening Time (PCC) Judging

Decrease Observation Number

Drop Time (Minutes)

Decrease(mm)

1

30

41

2

45

41

3

60

39

4

75

39

5

90

35

6

105

33

7

120

31

8

135

21

9

150

12

10

165

4

11

180

2

12

195

1

13

210

0

 

 

 

Table 7

Semen Gresik (PPC) Bonding Time Judgment

Decrease Observation Number

Drop Time (Minutes)

Decrease����������������������������������������������������� ���(mm)

1

30

41

2

45

41

3

60

41

4

75

41

5

90

40

6

105

35

7

120

28

8

135

21

9

150

16

10

165

3

11

180

1

12

195

0

 

 

 

From the results of cement testing, it can be concluded that:

1)      The specific gravity of greek cement and lime is smaller than that of conch cement.

2)      Of the two types of cement, conch cement is smoother than gresik cement.

3)      Semen Gresik has a smaller consistency.

4)      The initial setting time of Gresik cement is faster.

 

1. Calculation of Mortar Mixed Materials (Mix Design)

For the calculation of the planning of the mortar mix (mix design) according to SNI 03-6882-2002 the materials used such as water, fine aggregate of barito sand, lime and cement used are greek cement and conch, the proportions of the mixture of the 2 types of cement, fine aggregate, lime and water is all the same.

The calculation of mixed materials is in tables 7 to 8.

 

Table 8

Proportion of Gresik Cement Mixture

(PPC) And Cement Conch (PCC)

Mixed Proportion

Portland Cement

Fine Aggregate (Sand)

Volume Proportion

1

5

Filling Weight (g/m�)

1250

1530

Modifying Factor

0,392

0,392

Material Weight (g)

490

2998,8

 

Mortar with a mixture composition of 1 part portland cement and 5 parts sand based on a volume ratio. Conversion of volume ratio to weight ratio is calculated as follows:

For 1 x Mixing, 3000 grams of sand is recommended.

Mixed one-time modifier����� ����������� = 3000/(1530 x 5)���� =0,392

(Based on Sand Material)

Portland cement weight������������������� = 1 x 1250 x 0,392����� = 490 g

Sand Weight����������������������� ����������� = 5x 1530 x 0,392������ = 2998,8 g.

Water��������������������������������������������� = 425 ML

Water Cement Factor���������������������� = 0.87

One-mix modifier factor is the volume of material for one part in the volume ratio for one mix.

Table 9

Cement Mixture Proportion

Gresik+Lime and Cement Conch+Lime

Mixed Proportion

Portland Cement

Fine Aggregate (Sand)

Chalk

Volume Proportion

1

5

Filling Weight (g/m�)

1250

1530

806

Modifying Factor

0,392

0,392

0,392

Material Weight (g)

490

2998,8

394,94

 

Mortar with a mixture composition of 1 part portland cement, lime and 5 parts sand should be tested. Based on the comparison for the conversion from the volume ratio to the weight ratio is calculated as follows:

���� Mixed one-time modifier����� ����������� = 3000/(1530 x 5)= 0,392

���� Portland cement weight������� ����������� = 1 x 1250 x 0,392 = 490 g

Chalk Weight���������� ����������������������� =x 806 x 0,392 = 394,94 g

Sand Weight������������ ���� ����������������� = 5x 1530 x 0,392 = 2998,8 g.

Water���������������������������������� ������������= 410 ML

Water Cement Factor����������� ������������= 0,84

 

One-mix modifier factor is the volume of material for one part in the volume ratio for one mix.

1. Mortar Compressive Strength Test Results

The results of the compressive strength test of mortar according to SNI � 03-6825-2002 For variations in the type of cement there are 15 test objects and are divided into 4 mortar ages, namely 3, 7, 14 and 28 days. From the mortar compressive strength test, the following results were obtained:

The results of the compressive strength test of a mixture of cement mortar (PPC) and conch (PCC) mortar Table 4.9. For more details, see Appendix 2.

 

Table 10

Mortar Strength Test Results

No

Test Objects And Composition

Strong Press

Age 3 Days

Age 7 Days

Age 14 Days

Age 28 Days

1

Mortar (Cement Conch)

1 Sp : 5 Ps

2.31

4.50

8.74

7.07

2

2.31

5.27

5.91

5.52

3

3.98

3.73

5.91

7.45

4

 

 

 

9.76

5

 

 

 

7.19

Average

2.87

4.50

6.85

7.40

1

Mortar (Semen Gresik)

1 Sp : 5 Ps

1.80

3.34

11.05

9.25

2

2.70

6.04

6.94

9.76

3

2.44

2.96

9.25

12.21

Average

2.31

4.11

9.08

10.41

1

Mortar (Cement Conch+Lime)

1 Sp : Kp : 5 Ps

6.94

10.92

6.42

3.85

2

3.85

4.63

5.14

3.34

3

5.14

3.34

11.05

3.60

4

 

 

 

5.40

5

 

 

 

2.83

6

 

 

 

8.22

Average

5.31

6.30

7.54

4.54

1

Mortar (Semen Gresik+Lime)

1 Sp : Kp : 5 Ps

5.01

6.17

6.42

11.05

2

5.14

6.17

6.04

6.94

3

4.63

6.81

6.94

6.42

4

 

 

 

7.19

Average

4.93

6.38

6.47

7.90

 

From the results of mortar testing at the age of 3, 7, 14 and 28 days, there are several samples of test objects that must be removed because the results obtained are not in accordance with SNI due to non-technical errors so they must be removed.

The average compressive strength value shows that the average compressive strength of Gresik cement increases at the age of 28 days.

 

5. Graph of Mortar Test Results

���� Graph of Average Compressive Strength Against Mortar Age

 

Figure 2

Comparison Graph of Compressive Strength with Mortar Age

 

The compressive strength of mortar for the use of Semen Gresik and Semen Conch from the age of 3 days to 28 days there was an increase in the compressive strength, compared to Cement Conch with the addition of lime at the age of 3 days to 14 days an increase in the age of 28 days decreased the average compressive strength, while For mortars that use the addition of lime, Semen Gresik with a mixture of lime, the results of the average compressive strength of the age always increase and the normal without lime, Semen Gresik, the results increase as the age of the mortar increases.

 

6. Graph of Compressive Strength Against Mortar Age

The results of the compressive strength of mortar for each age, mortar can be seen in the graph of the results of the compressive strength.