Study Of Crack Pattern And Strength With Replacement Of Natural With Artificial Fine Aggregate In Concrete

Submitted By
Vinayak Ravindra Supekar.
(National Institute Of Construction Management And Research Center, (Nicmar))

ABSTRACT:
Now days the construction industry in the India is facing one of the major problem that is natural fine aggregate. And court awarded that totally band on excavation of fine aggregate from river because they affect on environment and changing the river direction. (fig.5). Thus the more natural fine aggregate are highly needed to replace with artificial fine aggregate. This paper presentation the study of crack pattern of concrete slab, each size is (500*300*50) mm and replacement of natural fine aggregate with artificial fine aggregate by 20%,40% 60% 100% and also finding the compressive Strength of that concrete cube. And these experiment is carried out maintain temperature 32 0cAnd the according to experimental result show that the replacement of natural sand by artificial sand up to 60% and gives best result that is maximum strength and minimum area of crack.

Key words: – Concrete slab, natural fine aggregate, artificial fine aggregate (grit), crack pattern.

INTRODUCTION-
The use of the artificial fine aggregate in concrete has increased rapidly in last few year because of more reduction in natural fine aggregate in river due to tremendous excavation. And also band on excavation from river (fig5) form court.

Concrete is the most widely used construction material because of its flow ability in most complicated from i.e. it is ability to take any shape while wet and its strength development characteristics when it hardens. Concrete requires consumption of virgin materials. It requires cement, water, and suitable aggregates. Its production involves a number of operations according to prevailing site condition. The ingredients of widely varying characteristics can be used to produce concrete of acceptable quality. The strength, durability, and other characteristics of concrete depend upon the properties of its ingredients. In concrete fine and coarse aggregate constitute about 75% of the total volume. It is therefore important to obtain right type and good quality aggregate at site. The aggregates from the main matrix of concrete of mortar.

Fine aggregate (smaller than 4.45) play a very important role in controlling the properties of fresh concrete. They help to improve cohesiveness of fresh concrete, improve workability and prevent segregation and bleeding of concrete.

So fine Aggregate is an essential component of concrete. The most commonly used fine aggregate is natural river or pit sand. The global consumption of natural sand is very high due to extensive use of concrete. In particular the demand of natural sand is quite high in developing countries owing of rapid infrastructural growth. In this situation developing countries are facing shortages in supply of natural sand.

Natural sand deposits are being depleted and causing serious threat to environment as well as the society. Increasing extracting of natural sand from river beds is causing many problems loosing water retaining sand strata Deeping of the river courses and causing bank slides, loss of vegetation on the bank of river, exposing the intake well of water supply schemes etc are few examples.

River sand is becoming a very scare material sand mining from our river becomes objectionable. Is has now reached a stages where it is killing all our rivers of our country from total depth. Also dams are constructed on every river hence these resources are erasing very fast. Now day good quality sand is not readily available so it is a need of the time to find some substitute to natural river sand some alternative material have already been used a a apart natural sand for examples fly ash slag and lime stone and siliceous stones powder were used in concrete mixtures as a partial replacement of natural sand. On this basis the present study has used manufactured sand in concrete mixtures as a partial replacement of natural sand.

Manufactured sand is a process controlled cursed aggregate produced from quarried stone by crushing or grinding and classification to obtain a controlled gradation product that completely passes the 4.75 mm sieve. I n this particle shape is influenced by the physical properties of the parent rock and by method of production. Manufactured sand generally contain more angular particles with rough surface textures and flatter face than natural sand that are more rounded as a result of weathering overtime some investigation have shown that angular particles, rough surface of manufactured sand influences the workability finish ability in fresh concrete. In most cases some improvement in bond with cement past is obtain as surface roughness, increases and strength of hardened concrete.

Manufactured sand have to satisfy the technical requisites like workability and strength of concrete since the on this aspect of concrete using manufactured sand is scarce it is necessary to investigate the concrete produced with manufactured sand.

EXPERIMENTAL WORK-
Material characteristics-
For this experiment each 20 % replacement of natural fine aggregate by artificial fine aggregate i.e. 0% ,20%, 40%, 60%, 80% &100% casted the three slab for each percentage that total 18 slab were casted and tested of crack pattern . The size of slab was (500*300*50)mm and six cube for each percentage that’s 54 cube were casted and size of cube was 150mm*150mm*150mm it was cast and tested of the compressive strength of cube. The concrete is made with mix design. The compositions of the concrete consisting of the ordinary Portland cement, coarse aggregate, definite proportion of natural and artificial fine aggregate and water. The coarse aggregate used in concrete mix with artificial fine aggregate i.e. grit . size of coarse aggregate was used 20mm and the water cement ratio used was 0.5. all of the slab and cube were cast at one time with steel slab and cube mould respectively in the laboratory. The cube were cured in good water available in the laboratory at room temperature32 0c. And crack pattern were tested after hardening of the slab i.e. avgas .period after 6 to 7 hr.

Test setup and test procedure-
The size of concrete slab was (500*300*50) mm and it was started the finding the cracks after slab was hardening i.e. period of after 6 to 7 hr. During observation all the cracks were marked on the transparent paper for finding the area of crack and measurement done with help of hand held microscope. The fig of the slab test is shown in fig 3 least count of microscope is 0.001mm. crack spacing is measured within all the slab. And the cube was tested with compression machine at the age of 28 days up to failure. The fig of the cube test is shown in fig 4 and finds the compressive strength of concrete.

RESULTS AND DISCUSSION:-
RESULTS OF FRESH CONCRETE PROPERTIES:-
The results of the slump test carried out on the fresh concert gives a good indication of workability of concrete. However the slump test is limited I its applications and better indication of workability as given from compacting factor also summary of fresh concrete

TEST RESULTS SHOWING FRESH CONCRETE PROPERTIES

Suggested mix proportion	Percentage replacement  of natural sand by artificial sand	Slump test (mm)	Compaction factor	Flow table test (%)
1:1.583:3.275	0	40	0.91	27.16
1:1.583:3.275	20	48	0.92	25.70
1:1.583:3.275	40	50	O.90	9.32
1:1.583:3.275	60	56	0.90	11.33
1:1.583:3.275	80	54	0.90	7.68
1:1.583:3.275	100	45	0.87	9.12

RESULTS OF HARDENED CONCRETE PROPERTIES;
COMPRESSIVE STRENGTH & CRACK AREA;
FOR this test crack patter area finding from table name SHEET A1 to table name SHEET F3 and according to experimental result it is states that Replacement of natural fine aggregate by 60% artificial fine aggregate is the best result because of maximum strength and minimum area of crack. And the compressive strength of concrete was determined by testing concrete cube of size (150*150*150) mm The test were carried out on the concrete at 28 days to determine rate of gain of strength

The compressive strength of concrete is determined by the following formula
F=P/A
Where,
F= Compressive strength of concrete.
P= maximum road measured during testing
A=Area of specimen being tested.

Test result of comp. strength of concrete (cube specimen) and area of crack.
For w/c ratio=0.5

Suggested mix proportion	Percentage replacement  of natural sand by artificial sand	Area of crack	Compressive strength (N/mm2)
1:1.583:3.275	0	13.33	23.48
1:1.583:3.275	20	2.59	27.12
1:1.583:3.275	40	2.22	31.38
1:1.583:3.275	60	1.21	35.16
1:1.583:3.275	80	3.23	33.28
1:1.583:3.275	100	5.22	33.27

TEST RESULTS USED FOR MIX DESIGN FOR MAKING CONCRETE:-
A) TESTS ON NATURAL FINE AGGREGATE:-
SPECIFIC GRAVITY OF NATURAL SAND-G= 2.7
WATER ABSORPTION =6%
SIEVE ANALYSIS OF NATURAL SAND= FINENESS MODULUS:- 2.9(ZONE II)
MOISTURE CONTENT OF NATURAL SAND=1%
B) TESTS ON MANUFACTURED (ARTIFICIAL) FINE AGGREGATE:-
SPECIFIC GRAVITY OF MANUFACTURED (ARTIFICIAL) FINE AGGREGATE=2.97
WATER ABSORPTION OF MANUFACTURED (ARTIFICIAL) FINE AGGREGATE= 6.5%
SIEVE ANALYSIS OF MANUFACTURED (ARTIFICIAL) FINE AGGREGATE= FINENESS MODULUS:-2.84 (ZONE II)
MOISTURE CONTENT= 1.

CONCLUSION:-
1) Replacement of natural fine aggregate by 60% artificial fine aggregate is the best result because of maximum strength and minimum area of crack.

2) When the replacement percentage of artificial sand is increases more than 60% the compressive strength decreases and area of crack increases.

3) Replacement of natural sand by manufactured fine aggregate improve the cube compressive strength of the matrix.

4) Replacement of natural sand by manufactured fine aggregate improves the workability of the matrix.

Showing the all the result of test

Suggested mix proportion	Percentage replacement  of natural sand by artificial sand	Slump test (mm)	Compaction factor	Flow table test (%)	Compressive strength (N/mm2)	Area of crack (mm2)
1:1.583:3.275	0	40	0.91	27.16	23.48	13.33
1:1.583:3.275	20	48	0.92	25.70	27.12	2.59
1:1.583:3.275	40	50	O.90	9.32	31.38	2.22
1:1.583:3.275	60	56	0.90	11.33	35.16	1.21
1:1.583:3.275	80	54	0.90	7.68	33.28	3.23
1:1.583:3.275	100	45	0.87	9.12	33.27	5.22

REFERENCES:-
BOOKS:-
1) M.S.SHETTY ‘concrete technology’ s.chand Co.Ltd. (2004).
2) M.L.Gamhir, ‘ concrete technology, Tata McGraw hill publishing co. ltd (2006)
JOURNALS:
1) Hudson B.P.( 1997) “ Manufactured sand for concrete”- The Indian concrete journal (may1997), pp 237-240
2) Nagaraj T.S. Zahinda Banu ( 1996) “ Efficient utilization of rock dust and pebbles as aggregate in Portland cement concrete’- The Indian concrete journal jan.1996, pp.53-56
3) Misra V.N. (1984) “ Use of stone dust from crushers in cement sand motors” the India concrete journal ,august 1984,pp 219-223
4) Lukkarila jay (2006) “ preparing a path for manufactured sand” concrete international, June 2006 pp 66-67
5) Babbie E.& mounton j. The practice or social research, Soutt African edition .Cape TOWN: oxford university press, 2005.

LIST OF REFERRED IS CODES:
1) IS 10262:1982: Recommended Guidelines for concrete mix design.
2) Sp 23: 1982 ; Handbook on concrete mixes
3) IS 383: 1970 Indian standards specification for coarse and fine aggregate from nature source for concrete
4) IS 12269-1987 Specification for 53 grade ordinate Portland cement.
5) IS 1199:1959 Method of sampling and analysis of concrete
6) IS 2386 : 1963 (PART I AND VIII) Methods of test for aggregate for concrete.

WEBSITE:-
1) http://oa.upm.es/8501/2/INVE_MEM_2010_83506.pdf
2) http://dspace.mit.edu/handle/1721.1/34636

FOLLOWING TABLE’S ARE RESULT OF CRACK’C OBERAVATION IN CONCRETE SLAB-
TABLES OF MEASURMENT OF CRACKS (USE TRANSPERNET SHEET)
SHEET NO -A1

SR.NO	LENTH	WIDHT	AREA
1	65	0.03	1.95
2	74	0.02	1.48
3	50	0.03	1.50
4	79	0.02	1.58
5	81	0.02	1.62

TOTAL                               8.13

SHEET NO –A2

SR.NO	LENTH	WIDHT	AREA
1	140	0.03	4.20
2	75	0.03	2.25
3	64	0.02	1.28
4	84	0.02	1.68
5	160	0.02	3.20
6	134	0.03	4.02
7	65	0.02	1.30
8	61	0.01	0.61

TOTAL                          18.54    AVERAGE-13.33

SHEET NO –B1

SR.NO	LENTH	WIDHT	AREA
1	35	0.01	0.35
2	36	0.01	0.36
3	32	0.01	0.32
4	33	0.01	0.33
5	39	0.0165	0.64
6	51	0.01	0.51

TOTAL            2.59

SHEET NO –B2

SR.NO	LENTH	WIDHT	AREA
1	43	0.01	0.43
2	64	0.0133	0.85
3	26	0.01	0.26
4	30	0.01	0.30
5	20	0.01	0.20
6	26	0.01	0.26

TOTAL                          2.30

SHEET NO –B3

SR.NO	LENTH	WIDHT	AREA
1	28	0.0133	0.37
2	27	0.0133	0.35
3	63	0.01	0.63
4	38	0.0133	0.50
5	48	0.0167	0.80
6	31	0.01	0.31

TOTAL                            2.96

AVERAGE:-2.59               

SHEET NO -C1

SR.NO	LENTH	WIDHT	AREA
1	30	0.01	0.30
2	35	0.01	0.35
3	33	0.01	0.33
4	32	0.02	0.64
5	48	0.02	0.48
6	30	0.01	0.30

TOTAL                 2.40

SHEET NO –C2

SR.NO	LENTH	WIDHT	AREA
1	34	0.01	0.34
2	30	0.01	0.30
3	29	0.02	0.58
4	48	0.01	0.48
5	48	0.01	0.48
6	34	0.01	0.34

TOTAL                             2.52

SHEET NO –C3

SR.NO	LENTH	WIDHT	AREA
1	20	0.02	0.40
2	21	0.02	0.42
3	24	0.01	0.24
4	28	0.01	0.28
5	18	0.01	0.18
6	24	0.01	0.24

 TOTAL                             2.52

 AVERAGE:-2.22

SHEET NO -D1

SR.NO	LENTH	WIDHT	AREA
1	40	0.01	0.40
2	31	0.01	0.31
3	32	0.01	0.32

TOTAL                             1.03

SHEET NO –D2

SR.NO	LENTH	WIDHT	AREA
1	24	0.01	0.24
2	35	0.01	0.35
3	23	0.01	0.23
4	32	0.01	0.32

TOTAL                             1.14

SHEET NO –D3

SR.NO	LENTH	WIDHT	AREA
1	34	0.01	0.34
2	51	0.0133	0.61
3	46	0.01	0.46

TOTAL                             1.47

 AVERAGE: – 1.21

SHEET NO -E1

SR.NO	LENTH	WIDHT	AREA
1	27	0.01	0.27
2	38	0.01	0.38
3	24	0.01	0.24
4	34	0.01	0.34
5	38	0.01	0.38

TOTAL  1.61

SHEET NO –E2

SR.NO	LENTH	WIDHT	AREA
1	37	0.01	0.37
2	27	0.01	0.27
3	60	0.01	0.60
4	37	0.01	0.37
5	36	0.03	1.08
6	41	0.03	1.23
7	52	0.03	1.36

TOTAL 5.48
SHEET NO –E3

SR.NO	LENTH	WIDHT	AREA
1	54	0.02	1.08
2	25	0.01	0.25
3	35	0.01	0.35
4	30	0.01	0.30
5	63	0.01	0.63

TOTAL          2.61                                                            AVERAGE:-3.23

SHEET NO –F1

SR.NO	LENTH	WIDHT	AREA
1	81	0.01	0.81
2	38	0.01	0.38
3	32	0.0133	0.43
4	46	0.02	0.92
5	76	0.01	0.76
6	107	0.01	1.07
7	44	0.01	0.44
8	70	0.01	0.70
9	56	0.01	0.56

TOTAL                             6.07

SHEET NO –F2

SR.NO	LENTH	WIDHT	AREA
1	63	0.01	0.63
2	90	0.01	0.90
3	54	0.02	0.54
4	42	0.01	0.42
5	66	0.01	0.66
6	54	0.01	0.54
7	40	0.01	0.40
8	49	0.01	0.49

TOTAL                             4.58

SHEET NO –F3

SR.NO	LENTH	WIDHT	AREA
1	52	0.01	0.52
2	68	0.01	0.68
3	48	0.01	0.48
4	57	0.01	0.57
5	32	0.01	0.32
6	58	0.01	0.58
7	49	0.01	0.49
8	46	0.01	0.46
9.	46	0.02	0.92

TOTAL 5.02
AVERAGE 5.22

We at engineeringcivil.com are thankful to Er. Vinayak Ravindra Supekar for submitting his research paper on Study Of Crack Pattern And Strength With Replacement Of Natural With Artificial Fine Aggregate In Concrete to us.

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