STRENGTH ANALYSIS OF CONCRETE EMBEDDED WITH COCONUT FIBER AND CLASS-F FLY ASH
Arihant Jain, Prof. Anil Sanodiya, Prof. Charan Singh Thakur Department of Civil Engineering, SRGI, Jabalpur, Madhya Pradesh, India
Abstract: The aim of the investigation is to study the variation in the strength characteristics of concrete, for the proportion of M20 grade. In each mix containing different percentages of fly ash is replaced by means of cement starting from 0% as normal concrete, i.e. controlled concrete 10%, 20%, and 30%, were used. The characteristics behavior of concrete is further enhanced by embedding coconut fibres with variable fibre sizes.
INTRODUCTION
The structural needs of our country is changing day by day & with concrete is a main constituent of construction material in a significant portion of this structural system, it is therefore necessary to enhance its characteristics in terms of strength &
durability. It is also desirable to compensate concrete by using waste materials and that results in a saving in cost by the use of admixtures such as fly ash, silica fume , coco-nut fibres etc. as partial replacement of cement. one of the many ways of achieving the objective is by developing new concrete composites with the fibers which are locally available.
Concrete becomes more brittle with increase in strength. & this is the major drawback since brittleness cause sudden &
catastrophic failure, especially in structures which are subjected to earthquake, blast or suddenly applied loads i.e., impact. This serious disadvantage of concrete can at least partially be overcome by the incorporation of fibers. The incorporation of fiber can cause a change in the failure mode under compressive deformation from brittle, thereby imparting a degree of toughness to concrete.
The utilization of fly ash as a waste material can be both on economic and environmental grounds and also because of its beneficial effects of lower water demand for similar workability, reduced bleeding and lower evolution of heat. The proportion of fly ash used as a cementitious component in concrete depends on several factors. The design strength and
workability of concrete, water demand and relative cost of fly ash compared with cement are particularly important in mixture proportioning of concrete.
To bring into focus the use of coconut fibers in concrete an experimental programme is planned to study the material characteristics under the introduced change. The primary objective of this investigation is to study the effect of fibres on the properties of concrete , in particular
; compressive strength.
LITERATURE REVIEW
The number of significant results has been reported on the use of fly ash in concrete &
coconut fibers in concrete.
Saravana Raja Mohan, and co-workers carried out experiment investigation to evaluate the properties of fly ash based coconut fiber composite cement was replaced with five percentages (10%, 15%, 20%, 25%, & 30%) of class c fly ash. Four percentages of coconut fibers (0.15, 0.3, 0.45 & 0.60%) having 40mm length were used. The fly ash based coconut fiber reinforced concrete shows a better performance than ordinary concrete.
The test result showed that the maximum compressive strength was obtained for a mix having a fiber length of 40mm 10% fly ash &
fiber content of 0.15% by weight and increase in strength over plain cement concrete was found to be 27.51 Mpa. The 7 day compressive strength of fly ash based fiber concrete was found to be as high as 18.95 Mpa which is about 25.91% more than ordinary concrete. Similarly 28 day
compressive strength was found to be about 27.51 Mpa and is 45.81% more than the ordinary concrete.
The maximum value of splitting tensile strength obtained is 4.75Mpa which is about 35.71% more than ordinary concrete the maximum strength was obtained for a mix with fiber length 40mm, fiber content 0.3%
by weight & 15% fly ash replacement of cement.
The maximum flexural strength obtained for coconut fiber reinforced concrete was 4.65 Mpa and that plain cement concrete was 4 Mpa.
A. Zuraida, S. Norshahida and co-workers.
Carried out experimental investigation on effect of fiber length variation on mechanical and physical properties of coir fiber reinforced cement albumen composite, Albumen protein was added as a binder and the coir fiber with the length of (2.5, 5, 10 and 20mm) was used as partial replacement of the cement mixture. Flexural strength and compressive strength, Bulk density moisture content and water absorption were investigated the test results showed that increase in fiber length increase the flexural strength. Incorporation of long fiber into cement paste however decreased the workability and thus introduced voids which resulted in low density. In fact, the water absorption & moisture content were also increased.
Alida Abdullah, and co-workers Carried out experimental investigation on the effect of natural fiber content on the physical &
mechanical properties of composite cement reinforce with coconut fiber. The mix design was based on 1:1 for cement sand ratio and 0.55 was fixed for amount of water per cement ratio. Coconut fiber was added as reinforcement and replacing the composition of sand. Composites wete developed base on 3% wt, 6%wt, 9% wt, 12% wt & 15%wt of coconut fiber by mixing
& curing process. Composite were cured in water for 7, 14 & 28 days the test results showed that the composite reinforced with 9% wt of coconut fiber demonstrated the highest strength of modulus of rapture and compressive strength.
Wilson O Tablan carried out the experimental investigation on effect of coconut fiber as reinforcement to concrete on its flexural strength and cracking behavior. 25% coconut fiber was added as reinforcement. The ratio of 1:2:4 mixture of concrete was used in making the specimen
& curing the period of 28 days. The result showed that the concrete reinforced with coconut fibers yielded a higher flexural strength compared to concrete without coconut fiber reinforcement. More ever the concrete with coconut fiber indicated transformation from abrupt to gradual failure of the specimens and splitting when ultimate load was applied hence the added coconut fibers enhanced the flexural strength of the concrete.
Tan Eng slang carried out experimental investigation on effect of coconut fiber &
egg albumen to properties of the concrete such as the compressive strength & flexural strength. The three types of concrete mixture were concrete containing 0.1%
coconut fiber & 1% egg albumen, concrete containing 0.5% coconut fiber & 0.5% egg albumen and concrete control sample from analysis showed that the both the additives of coconut fiber & egg albumen with concrete in different percentage show improvement in the development of the strength. By compairing concrete containing 0.1% coconut fiber & 0.1% egg albumen with concrete containing 0.5%
coconut fiber & 0.5% egg albumen, the strength of lower percentage additive was higher than the higher percentage of additive.
Observational - Arrangement
S l . N o .
Partic ular
M ix D es ig n
C o d e
No.
of Sp eci me n
Curi ng peri od in day s
Per ce nta ge of fly- as h
Perc enta ge of coco
nut fibre
1 Cube, 150m m
M 2 0
M 1 9
7, 14,2
8 0
0
2
Cube, 150m m
M 2 0
M
2 9 7,14 ,28 10
0
3
Cube, 150m m
M 2 0
M
3 9 7,14
,28 20 0
4
Cube, 150m m
M 2 0
M
4 9 7,14 ,28 30
0
5
Cube, 150m m
M 2 0
M
5 9 7,14 ,28 10
0.25, 20m m
6
Cube, 150m m
M 2 0
M
6 9 7,14
,28 20 0.25, 20m m
7
Cube, 150m m
M 2 0
M
7 9 7,14 ,28 30
0.25, 20m m
8
Cube, 150m m
M 2 0
M
8 9 7,14 ,28 10
0.25, 40m m
9
Cube, 150m m
M 2 0
M
9 9 7,14
,28 20 0.25, 40m m
1 0
Cube, 150m m
M 2 0
M 1
0 9 7,14 ,28 30
0.25, 40m m
1 1
Cube, 150m m
M 2 0
M 1 1 9
7,14 ,28 10
0.25, 60m m
1 2
Cube, 150m m
M 2 0
M 1 2
9 7,14 ,28 20
0.25, 60m m
1 3
Cube, 150m m
M 2 0
M 1 3
9 7,14
,28 30 0.25, 60m m
1 4
Cube, 150m m
M 2 0
M 1 4
9 7,14 ,28 10
0.5,2 0mm
1 5
Cube, 150m m
M 2 0
M 1 5
9 7,14 ,28 20
0.5,2 0mm
1 6
Cube, 150m m
M 2 0
M 1 8
9 7,14
,28 30 0.5,2 0mm
1 7
Cube, 150m m
M 2 0
M 1 7
9 7,14 ,28 10
0.5,4 0mm
1 8
Cube, 150m m
M 2 0
M 1 8
9 7,14 ,28 20
0.5,4 0mm
1 9
Cube, 150m m
M 2 0
M 1 9
9 7,14
,28 30 0.5,4 0mm
2 0
Cube, 150m m
M 2 0
M 2 0
9 7,14 ,28 10
0.5,6 0mm
2 1
Cube, 150m m
M 2 0
M 2 1
9 7,14 ,28 20
0.5,6 0mm
2 2
Cube, 150m m
M 2 0
M 2 2
9 7,14
,28 30 0.5,6 0mm
Description of workability and magnitude of slump Description of
workability Slump in mm
No slump 0
Very low 5 – 10
Low 15 – 30
Medium 35 – 75
High 80 – 155
Very high 160 to collapse
Table No. : Workability of various concrete mixes design for slump cone
test is as follows
Mix design codes Slump cone test in mm.
M1-MIX (normal
concrete) 38
M2-MIX (10% fly ash) 42 M3-MIX (20% fly ash ) 43 M4-MIX (30% fly ash ) 45
M13-MIX (30% fly
ash,0.25% fiber) 47 M22-MIX (30% fly ash,
0.5% fiber) 48
Compressive Strength of Grade M20 as M1, M2, M3, M4, M5, M6
Mi x M-
1 M- 2 M-
3 M- 4 M-
5 M- 6 Fly
as 0 10 20 30 10 20
(%)
FI BE
R (%)
0 0 0 0 0.2
5 0.2
5
FI BE
R LE NG TH
0 0 0 0
20 m m
20 m m
Te st ag
e (da ys)
3-3 SAMPLES
COMPRESSIVE STRENGTH (N/mm²)
7 12.
0 12.
5 12.
0 Av
=1 2.
1 12.
6 12.
5 12.
6 Av
=1 2.5
6 13.
3 13.
2 13.
4 Av
=1 3.
3 13.
7 13.
8 13.
9 Av
=1 3.
8 15.
3 15.
5 15.
1 Av
=1 5.
3 14.
8 14.
0 14.
4 Av
=1 4.
4
14 15.
0 15.
0 15.
6 Av
=1 5.
2 16.
7 16.
8 16.
9 Av
=1 6.8
17.
7 17.
8 17.
9 Av
=1 7.
8 18.
4 18.
3 18.
5 Av
=1 8.
4 19.
0 21.
8 20.
4 Av
=2 0.
4 19.
2 20.
5 18.
5 Av
=1 9.
2 19. 20. 22. 22 26. 25.
28 5 19.
0 19.
5 Av
=1 9.
3 0 21.
0 22.
0 Av
=2 1
2 22.
3 22.
4 Av
=2 2.
3
23 21 Av
=2 3
5 24.
5 25.
5 Av
=2 5.
5 0 23.
0 24.
0 Av
=2 4
Showing the variation of fly ash and fiber percentage versus compressive strength in n/mm2 of M20 grade
Results and Discussion of Compressive Strength:
Compressive strength of concrete mixes made with and without fly ash and coconut fiber with different percentage and varation in length of fiber were determined
at 7, 14, and 28 days of curing. The test results are given in table and shown in figure. The maximum compressive strength was obtained for a mix having a fiber length of 40 mm, 10% fly ash and fiber content of 0.25% by weight and increase in strength over plain concrete and fly ash concrete without fiber content.
The 7 day compressive strength of fly ash based coconut fiber concrete was found to be high as 17.9 Mpa. Which is more than ordinary concrete and fly ash concrete. Similarly 28 day compressive strength was found to be about 27 Mpa which is more than that of ordinary concrete and fly ash concrete.
The effect of replacement of cement with three percentages of fly ash and addition of coconut fibers on the compressive strength of concrete is shown figure. It is clear that the replacement of cement with 30 % of fly ash reduced the compressive strength of concrete. And for a particular percentage of fly ash there was a decrease in compressive strength of fly ash concrete, as the percentage of fiber increased from 0.25% to 0.5%. However, this reduction in strength with addition of fibers continued to decrease with an increase in the percentage of fly ash content. Generally, presence of fibers induces porosity and reduces compressive strength depending upon fly ash content.
REFERENCES
1. Saravana raja mohan, P.Jayabalan, A Rajaraman on properties of fly ash based coconut fiber composite, American Journal of Engg and Applied Science 5(1):29-34,2012
2. A.Zutaida, S.Norshahida, I.Sopian and H.Zahurin (malaysia) on effect of fiber length variation on mechanical and physical properties of coir fiber reinforced cement albumen composite.
IIUM Engg Journal Vol.12 No 1, 2011.
3. Alida Abdullah, Shamsul Baharin Jamaludin, Mazlee Mohd Noor, Kamarudin Hussin on Composite
Cement Reinforced Coconut Fiber:
Physical and Mechanical Properties Australian Journal of Basic and Applied Sciences, 5(7): 1228-1240, 2011
4. Wilson o. tablan Flexural Strength of Concrete Beams Containing Twinned Coconut Fibers Vol 5 No.1 December 2007 ISSN: 2094-1064
5. Majid Ali Coconut fibre: A versatile material and its applications in engineering Journal of Civil Engineering and Construction Technology Vol. 2(9), pp. 189-197, 2 September, 2011
Available online at
http://www.academicjournals.org/jcect ISSN 2141-2634 ©2011 Academic Journals.
6. Tan eng slang effect of coconut fibre and egg albumen in concrete for greener environment.
7. Ben Davis on Natural Fibre Reinforced Concrete.
8. Baruah and Talukdar properties of plain concrete and coconut fiber reinforced concrete Journal of Civil Engineering and Construction Technology Vol. 2(9), pp. 189-197, 2 September, 2011 Available online at http://www.academicjournals.org/jcect ISSN 2141-2634 ©2011 Academic Journals
