APPLICATION OF COCONUT FIBER

IN CEMENT BLOCK INDUSTRY

G.A.P Gampathi a
a
Department of Civil Engineering , PNG University of Technology , PMB , Lae,
Morobe Province , Papua New Guinea.
a
Corresponding author: gampathipp@yahoo.com
© Ontario International Development Agency. ISSN 1923-6654 (print)
ISSN 1923-6662 (online). Available at http://www.ssrn.com/link/OIDA-Intl-Journal-Sustainable-Dev.html

Abstract: In the recent times, seismic effects have property. To significantly improve life quality, new
become major governing factor in analysis, design techniques for economical and safe housing are
and construction of structures in Papua New Guinea. required [1].
This is mainly due to the occurrence of severe Natural fibers reinforced cement based material has
earthquakes in the region. As to the current gain increasing application in residential components.
construction practices, most of the earthquake The use of natural fiber such as Coir, Oil palm,
resistive structures are designed with cement hollow Bamboo, Coca offer advantages such as availability,
block providing require reinforcements. However, renewability, low cost and the established technology
this construction method is very expensive and not to extract the fibers [2]. However addition of high
affordable for middle class families. Therefore, an natural fiber content to cement block mixture reduced
experiment was carried out by author to find out the the compressive strength and self weight of the
suitability of coconut fiber application in cement blocks, the resulting blocks could be classified as
hollow block work. The experimental study was lightweight cement blocks suitable to be used as
focused to apply coir fiber to enhance the shear lightweight walling materials [2-3]. In the recent
strength of cement hollow block as a cost effective studies on various natural fibers shown that Coir fiber
and sustainable practical solution. is more suitable as construction material due to its
high tensile capacity together with other properties
The results presented in this paper on the basis of the
including durability over other fibers [3]. There are
results of the testing about 40 cement hollow blocks
many general advantages of coconut fibers, e.g. they
carried out by the author for various percentages of
are moth-proof, resistant to fungi and rot, provide
coir fiber by cement weight . It can be seen from the
excellent insulation against temperature and sound,
experimental result that shear strength of cement
not easily combustible, flame-retardant, unaffected
hollow block can be increased by 40 % with addition
by moisture and dampness, tough and durable, totally
of 3 % coconut fiber by cement weight to cement
static free and easy to clean[4]. As per recent
hollow blocks mixture. Therefore using coir fiber
researches coir fiber is widely used as reinforcement
reinforced cement hollow block instead of normal
in concrete to increase shear capacity of concrete
cement hollow block; required steel quantity can be
elements [5]. Eventhough coir fiber is used in
reduced. Hence overall construction cost of
concrete; it is not used in cement block up to now.
earthquake resistive walls can be reduced.
Therefore study on coir fiber application in hollow
Keywords: Cement hollow block, Coir fiber, cement block is very important, especially in
Earthquake, Seismic effects, Sustainable earthquake resistive wall design. The current practice
of using steel in earthquake resistive wall design is
I. INTRODUCTION not affordable by local middle class peoples.
Therefore , Coir fiber reinforced hollow cement

E
arthquakes of considerable magnitudes are
occurring frequently in the recent years, and block can be one solution, which required suitable
causing mass destruction of buildings because quantities of coir fibers in standard hollow cement
of exceeding the designed limit of resistivity to block mixture. Coir fiber is available in Papua New
earthquake load. This ultimately in loss of life and
84 G.A.P Gampathi / OIDA International Journal of Sustainable Development 02:09 (2011)

Figure 1: Seismic Designed Cement Hollow Block Wall

Figure 2: Coconut Fiber

Guinea and cost of production is very low, hence the II. EXPERIMENTAL PROCEDURE
additional cost of building is negligible.
Raw Materials: Ordinary Portland cement, locally
The current urban buildings in Papua New Guinea
available fine sand (d50 = 1.0mm), water and locally
are mostly 2 storied building and build with cement
available brown coir fiber were used for making
hollow block providing required reinforcement for
cement hollow blocks.
earthquake load, e.g. Fig. 1. However, there are
Preparation of Coir Fibers: Coir fibers were
considerable failure cases in building due to frequent
extracted from local brown coconut husks. Those
occurrence of moderate earthquake. Therefore,
fibers were immersed in water for the period of two
replacement of normal cement hollow block by coir
weeks before final clearing. The cleaned fibers were
reinforced cement hollow block may be a sustainable,
combed before placing in an Owen for 1 day. During
economical and practical solution to improve
this processes 80% of moisture was removed; and
earthquake resistivity of the building while reducing
then fibers were dried in the open air. After
total steel requirement.
completing drying processes, fibers were again
combed and cut into 5.0 cm length. The following
Fig. 2 showed some extracted clean coir fiber.
 G.A.P Gampathi / OIDA International Journal of Sustainable Development 02:09 (2011) 85

Figure 3: Pan Type Mixture Figure 4: Finished bricks

Figure 5: Compressive Strength Test

Table 1: Compressive Strength Test Results

Sample No. Coir content by cement weight (%) Compressive strength (MPa)
1 0 13
2 0 12
3 0 13
4 0 12
5 1 13
6 1 13
7 1 12
8 1 12
9 2 12
10 2 11.8
11 2 11.8
12 2 11.6
13 3 11
14 3 11
15 3 11
16 3 11
86 G.A.P Gampathi / OIDA International Journal of Sustainable Development 02:09 (2011)

Mix Design and Casting Procedure So far mechanical strength properties are
representing the compressive strength bricks only. No
For cement brick mixture, the mix design ratio for
much work on shear strength of brick was reported
cement and sand was 1 and 4, respectively with water
by researchers. But fiber reinforced concrete
cement ratio of 0.40. The mix design for coir fiber
possesses improvement in shear. Bairagi N.K [6]
reinforced brick mixtures were the same as above
proposed a method to determine the shear strength of
except that addition of coir fiber 1%, 2% and 3% by
fiber reinforced concrete, which was applied to
cement weight in each cases.
measure the shear strength of hollow block mixtures
The pan type of concrete mixture, shown in above
in this study.
Fig. 3, was used in preparing brick mixture. For
Based on literature, L-shaped shear test specimens
making bricks without coir fiber, first, sand and
were prepared from 150mm cubes by inserting a
cement were put into the concrete mixture and
wooden block of 90mmx60mm in cross section and
allowed to mix it for three minutes and then water
150mm high into the cube moulds before casting of
was added very slowly with a measuring container
concrete. All test specimens were casted and cured
and mixed for three minutes to form brick mixture for
for 28 days. The specimens were placed as shown in
casting bricks. For the coir fiber reinforced brick
Fig. 6 on compression testing machine. A 150x85x10
mixture, same process was followed with spreading
mm size MS plate was placed on 90 mm face of left
coir fiber on sand and cements mixture after adding
side portion. Mild steel bar of 12mm diameter was
water and allowed to mix for three minutes. The
placed over the centre of the plate. Another 22mm
prepared mixture was put into a brick mould and well
diameter MS bar was placed at the edge of the plate.
compacted to form hollow cement blocks. The
Over these bars, another MS plate of size
following Fig. 4 shows finished hollow brick
150x110x10mm was placed. Load was applied on the
samples. All the blocks were well cured for 28 days
plate which forms shear plane below the centre of
before testing.
22mm diameter bar. The loading was continues until
Compressive Strength Test for Cement Hollow the specimen failure. The shear strength was obtained
Blocks using the following equation:
After 28 days of curing, a total of 16 numbers of
cement hollow blocks, 4 numbers from each 0%, 1%, P
2% and 3% coir fiber mixed blocks were tested for
fs 
A
compression. All compressive strength tests were
carried out according to Papua New Guinea standard
specifications. The testing is shown on Fig.5 and the Where, fs – shear strength, P – Applied compression
results are shown on the Table 1. load, A – Shearing area
Average shear strength for 12 tested samples
Shear testing for Cement Hollow Blocks.
according to percentages of coir content by cement
weigh are shown on the following Table 2.

Table 2: Shear Strength Test Results

Series No. Coir content by cement weight (%) Average shear strength (MPa)
1 0 2.9
2 1% 3.8
3 2% 4.0
4 3% 4.1

Figure 6: Shear testing

 G.A.P Gampathi / OIDA International Journal of Sustainable Development 02:09 (2011) 87

Figure 7: Average Compressive Strength Variation

Shear strength test results. Average shear strength variation for 12 tested samples are shown on the following Fig.
8. It can be seen from the graph that shear strength of cement hollow block mixture is increasing with the increases
of coir fiber percentage.

Figure 8: Average Shear Strength Variation

III. TEST RESULTS AND ANALYSIS IV. CONCLUSION

Compressive strength test results. Average This study was focused to increase shear strength of
compressive strength of cement hollow block for cement hollow blocks by coir fiber reinforcement
each coir fiber percentages are shown in the without altering its compressive strength. The study
following Fig. 7. It can be seen from the results that was carried out by testing series of cement hollow
compressive strength of concrete is reducing with the blocks with and without coir fiber reinforcement. The
increases of coir fiber percentage. workability of standard mixtures for cement hollow
88 G.A.P Gampathi / OIDA International Journal of Sustainable Development 02:09 (2011)

block have not carried out due to slump value is REFERENCES

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The authors would like to thank all persons who
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helped them throughout the research, particularly
Paul Isan, Victor Lalavake, Jone and Prof. Y. Telue,
the head of department of Civil Engineering, PNG
university of Technology for technical and financial
support of this research.