International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016

www.ijaser.in ISSN: 2455-9288

EFFECT OF MAGNESITE – BENTONITE POWDER ON THE COMPRESSIVE STRENGTH OF CEMENT MORTAR P.Santhoshkumar (AP/Civil Engineering, Al-Ameen Engineering college)Email: [email protected]) Abstract: The utilization of innovative material becomes mandatory in recent days due to developing population, which is now a great challenge to the society, because of the scarcity of materials.This project “Effect of Magnesite - Bentonite powder on the Compressive Strength of Cement Mortar” utilizes the magnesite and bentonite powder for making innovative mortar that is eco-friendly. Various combination of these two ingredients and the compressive strengths are recovered out in various phases with various proportions. From the experimental analysis, the compressive strength of the mortar made using the combination of magnesite powder and cement gave better results than the combination of bentonite with cement and magnesite with bentonite powder. Keywords : Bentonite, Cement Mortar, Compressive Strength, Eco-Friendly Mortar, Magnesite Powder,

I. INTRODUCTION The first mortars were made of mud and clay. Because of a lack of stone and an abundance of clay, Babylonian constructions were of baked mortar, using lime or pitch for mortar. According to Roman Ghirshman, the first evidence of humans using a form of mortar was at the ziggurat of Sialk in Iran, built of sun-dried mortar in 2900 BC. Gypsum mortar was essentially a mixture of plaster and sand and was quite soft. Few of such products have already been identified like Rice Husk Ash (RHA), Fly Ash, Silica Fumes, etc., In our study, Magnesite powder as an additive will be used with Bentonite powder as a cementitious material for making Mortar. Bentonite is composed primarily of montmorillonite and is useful in a wide range of applications. Magnesite is a mineral of the calcite group of the carbonate minerals. Its composition is MgCO3 , containing 47.82 percent MgO, 52.18 percent Co2 , and isomorphic admixtures—often Fe, more rarely Mn and C.

II. LITERARTURE REVIEW Kaci, et.al , reports that fine mineral additives are often used in the formulation of readymix mortars as thickeners and thixotropic agents. Yet, these attributed fresh state properties are not clearly defined from the rheological point of view. In the present study, we consider the influence of Bentonite (montmorillonite-based clay mineral) on the rheological behaviour of mortars, including in particular creep and thixotropy. The mortar pastes are subjected to different shearrates and then allowed to creep under fixed shear stresses until reaching steady state, which corresponds to either rest if the applied stress is smaller than the yield stress or permanent flow otherwise. The evolution of the creep strain is investigated depending on shear history for different contents of Bentonite. The microstructure rebuilding kinetics after shear (thixotropy) is considered by analysing the temporal evolution of the creep strain for different applied shear stresses (lower than the yield stress). As expected, Bentonite is found to enhance the mortar creep (or sag) resistance. This enhancement consists of both an increase of the yield stress recovered after shear, and a diminution of the characteristic time for yield stress recovery (related to microstructure rebuilding). Gopal,V., has reported on magnesite that there are three kinds of magnesite, namely, (i) cryptocrystalline (ii) crystalline, and (iii) amorphous. This classification is on the basis of the structure af magnesite.Magnesite is formed by the alteration of dolomitic limestone by magnesium-bearing solution associated with the intrusive rocks. The crystalline varieties of magnesite are the products of such alterations. The crypto crystalline varieties are the products of Copyright © 2016 by the Authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016

www.ijaser.in ISSN: 2455-9288

alteration of serpentine and of similar magnesium bearing rocks. Magnesite of this type is found extensively in an area where there are serpentine rocks and it occurs in fissuresor in the sheerzones thoroughly mixed' up with serpentine, along with some opal and chalced only. Magnesite resulting from the alteration of serpentinous rock is morphous in nature. Material Testing Test Results of Cement S.NO DESCRIPTION 1 Specific gravity 2 Fineness

RESULT 3.06 2%

3 4 5

31% 30.7 minutes 10.3 hours

Consistency Initial setting time Final Setting Time

Test Results of Fine Aggregate S.NO DESCRIPTION

RESULT

1

Specific gravity

2.68

2

Surface Moisture

2.71%

3

Water Absorption

0.51%

4

Fineness modulus

3.13

Test Results of Magnesite Powder S.NO DESCRIPTION 1 Specific gravity 2 Consistency

RESULT 1.97 33%

Test Results of Bentonite Powder S.NO 1 2 3 4

RESULT 1.97 27% 34.28% 28

DESCRIPTION Specific gravity Water absorption Plastic Limit Liquid Limit

Compressive Strength The strength of the mortar depends on the properties and proportions of the constituent materials, degree of hydration, and the rate of loading, method of testing and specimen geometry. The properties of the constituent materials which affect the strength are the quality of Magnesite and Bentonite powder. The compressive strength of mortar was determined by using 70.6mm x 70.6mm x 70.6mm mould. The test result of 7, 14, 28 days compressive strength are in table. We have completed three phase and by comparing the three phases, phase I is comparatively better. First two phase were the analysis of each Magnesite and Bentonite powder which results in low compressive strength. So the combination of Magnesite and Bentonite powder results are discussed below.

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International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016

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III. TEST RESULTS

NO

Table: Compressive Strength at the age of 7 days, C+M+B:S(1:3), W/C=0.45 B+M 0% B+M B+M B+M S. N/mm² 5% 10% 15% N/mm2 N/mm2 N/mm2 17.269

1

18.273

2

15.663

3 Av

17.068

g

15.462

15.060

12.651

15.863

14.257

12.249

15.267

13.855

13.052

15.529

14.391

12.651

B+M 20% N/mm 2

11.84 7 12.04 8 11.25 5 11.71 3

Compressive Strength in N/mm²

18

16 14 12 10 7th Day

8 6 4 2 0 0

5

10

15

20

% Replacement of Cement by Magnisite+ Bentonite Fig: Compressive Strength at the age of 7 days

Table: Compressive Strength at the age of 14 days, C+B:S(1:3), W/C=0.45

S.

B+M 0% N/mm²

NO

1

23.092

B+M 5% N/mm2

B+M 10% N/mm2

B+M 15% N/mm2

16.667

16.867

14.858

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B+M 20% N/mm 2

13.05 2 728

International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016 27.309

2

25.502

3 Av

25.301

g

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17.267

16.466

15.662

17.671

16.267

14.458

17.202

16.198

14.993

13.65 5 13.25 3 13.32 0

Compressive Strength in N/mm²

30 25

20 15

Compressive Strength

10 5 0 0

5

10

15

20

% Replacement of Cement by Magnisite+ Bentonite Fig: Compressive Strength at the age of 14 days

Table: Compressive Strength at the age of 28 days, C+B:S(1:3), W/C=0.45

S. NO

1 2 3 Av g

B+M 0% N/mm² 28.50 33.33 31.12 30.98

B+M 5% N/mm2

B+M 10% N/mm2

B+M 15% N/mm2

20.281

16.679

17.671

21.687

18.273

17.269

22.289

20.682

18.473

21.419

19.545

17.804

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B+M 20% N/mm 2

15.46 2 15.65 9 15.06 6 15.06 0

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International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016

www.ijaser.in ISSN: 2455-9288

Compressive Strength in N/mm²

35 Compressive Strength

30 25 20 15 10 5 0 0

5

10

15

20

% Replacement of Cement by Magnisite+ Bentonite Fig: Compressive Strength at the age of 28 days

Table: Comparison of Compressive Strength at age of 7, 14, 28 days Age in Days

M+B 0% N/mm²

M+B 5% N/mm²

M+B 10% N/mm²

M+B 15% N/mm²

M+ B 20% N/m m²

7

17.06

15.529

14.391

12.651

11.7 13

14

25.30

17.202

16.198

14.993

13.3 20

28

30.98

21.419

19.545

17.804

15.0 60

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International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016

www.ijaser.in ISSN: 2455-9288

Compressive Strength in N/mm²

35 30 25 20

7th Day

15

14th Day 28th Day

10 5 0 0

5

10

15

20

% of Replacement of Cement by Magnisite+ Bentonite Fig: Comparison of Results of % Replacement of Cement by B+M

Discussions: From the above results it is identified that the compressive strength decreases with the addition of Magnesite + Bentonite. The combination of Magnesite and Bentonite does not give satisfactory results. Table: Comparison of Compressive Strengths of M, B, M+B Compressive Strength at the Age of 28th Day(N/mm²) Descripti on

5%

10%

15%

20%

M

17.671

19.545

22.758

24.029

B

27.309

25.167

22.356

21.619

M+B

21.419

19.545

17.804

15.060

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International Journal of Advanced Science and Engineering Research Volume: 1, Issue: 1, June 2016

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30 25 20 Magnesite

15

Betonite 10

Magnesite+Bentonite

5 0 5

10

15

20

% of Replacement of Cement by M,B,M+B

Fig: Comparison of Results of M, B, M+B

CONCLUSION In this project we have successfully completed the study on compressive strength of mortar using magnesite powder and Bentonite powder. We have completed three phases and by comparing the three phases, phase I is comparatively better. The compressive strength is lower at 5%,10% and 15% of magnesite replaced with cement. The compressive strength is optimum at 20% of magnesite and nearly equal to the conventional mortar. The compressive strength decreases on further addition of magnesite. By replacing cement with 20% of magnesite the heat of hydration is greatly reduced and the environment is pollution free. Hence by using 20% of magnesite with cement, the amount of cement used is reduced. At the end of our study, we gained enough knowledge in developing a innovative mortar having less heat of hydration and eco-friendly.

REFERENCES 1. A. Kaci, M. Chaouche, P-A. Andréani, “Influence of bentonite clay on the rheological behaviour of fresh mortars” Cement and Concrete Research, Volume 41, Issue 4, April 2011, Pages 373-379. 2. Gopal,V, “Handbook on Magnesite” Magnesite Industry in Tamil Nadu, Tanmag, Salem 1985, P. 90. 3. J. Mirza, M. Riaz, A. Naseer, F. Rehman, A.N. Khan, Q. Ali, “Pakistani bentonite in mortars and concrete as low cost construction material”, Applied Clay Science, Volume 45, Issue 4, August 2009, Pages 220-226. 4. O Salli Bideci, Sabit Oymael, A Bideci, “The Effect of Mgo Admixture on Cement Pastes and Mortars”, Materials Science,Feb 2011, pages 1-7 .

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5. Shazim Ali Memon, Rao Arsalan, Sardar Khan, Tommy Yiu Lo, “Utilization of bentonite as a partial replacement of cement in concrete” , Construction and Building Materials, Volume 30, May 2011, Pages 237-242 6.

IS 12269: 1987 Specification for 53 grade ordinary Portland cement.

7.

M.S.Shetty,”Concrete Technology Theory and Practise”, Reprint 2011 Pages 27-

123.

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