COMPRESSIVE BEHAVIOUR OF FLAX FRP TUBE CONFINED COIR FIBRE REINFORCED CONCRETE

BEFIB2012 – Fibre reinforced concrete
Joaquim Barros et al. (Eds)
UM, Guimarães, 2012

COMPRESSIVE BEHAVIOUR OF FLAX FRP TUBE CONFINED COIR
FIBRE REINFORCED CONCRETE
* † †† †††
L. Yan , X. Yuan , C. Nguyen , N. Chouw

*
Dep. Civil & Environ. Eng., University of Auckland
Private Bag 92019, Auckland 1142, New Zealand
e-mail: lyan118@aucklanduni.ac.nz, web page: www.auckland.ac.nz

†
Dep. Mechanic. Eng., University of Auckland
e-mail: xw.yuan@auckland.ac.nz, web page: www.auckland.ac.nz

††
Mater. Accelerator, University of Auckland
e-mail: c.nguyen@auckland.ac.nz, web page: www.auckland.ac.nz

†††
Dep. Civil & Environ. Eng., University of Auckland
e-mail: n.chouw@auckland.ac.nz, web page: www.auckland.ac.nz

Keywords: coir fibre, flax fibre, FRP, stress-strain behaviour, confinement.

Summary: This study addresses the contribution of flax fibre reinforced polymer (FFRP) and coir fibre
reinforced concrete (CFRC) to the compressive strength of the composite structure. FFRP tubes made
by flax fabric reinforced epoxy resin composites were fabricated with infilled plain concrete (PC) or
CFRC. The considered coir fibre content is 1 wt. % of concrete and the fibre length is 40 mm. Uniaxial
compression tests were performed on the FFRP tube confined PC and CFRC specimens. The axial
stress-strain relationship, confinement effectiveness, failure mode and ultimate axial strain of the
FFRP confined PC and CFRC were investigated. The test results showed that FFRP tube significantly
enhance the compressive strength and ultimate axial strain of both PC and CFRC, i.e. PC confined by
4-layers of FFRP tube experiences respectively 199 % and 1047 % enhancement in the compressive
strength and ultimate axial strain. The stress-strain curves of FFRP confined PC and CFRC exhibit a
bi-linear manner. The failure mode of FFRP tube confined PC and CFRC is dominated by the rupture
of FFRP tube when its tensile strength in the hoop direction exceeds its tensile strength obtained from
FFRP flat coupon tests. It was also found that coir fibre inclusion reduces the concrete cracks width for
both PC and FFRP confined PC.

1 INTRODUCTION
In recent years, fibre reinforced polymer (FRP) composite materials, with their high stiffness and
strength-to-weight ratios, design flexibility and corrosion resistance performance, have been widely
applied in civil engineering to strengthen concrete structures [1-10]. FRP materials were firstly used for
confining steel reinforced concrete columns as external wrapping for seismic retrofit and rehabilitation.
In the 1990s, Mirmiran and Shahawy [1, 8] proposed the concrete filled FRP tubes (CFFT) system.
FRP materials in the form of pre-fabricated tubes were considered in this new construction system.
The FRP tubes were manufactured using filament-winding techniques or hand lay-up process. These
tubes, acting as stay-in-place structural formwork for fresh concrete, can also protect the encased
concrete from the potential aggressive environment, e.g. de-icing salts and other chemicals [2-5]. The
laminate structure of the FRP tube can generally be engineered to offer the desired strength and

BEFIB2012: L. Yan, X. Yuan, C. Nguyen and N. Chouw

stiffness in a specific direction by controlling the numbers of layers and angles at which layers of fibres
are oriented. Therefore, the FRP tubes can effectively replace conventional steel reinforcement to
increase concrete compressive strength and ductility [2-7].
Fardis and Khalili [7] proposed the concept of the FRP tube encased concrete structures in the
1980s, they investigated the behaviour of circular and rectangular FRP confined concrete beams and
concluded that FRP tubes increased concrete compressive strength while decreasing structural
weight. So far the compressive behaviour of FRP confined concrete has been widely studied by many
researchers [9-18].
Mirmiran and Shahawy [1], Xiao and Wu [9] and Lam and Teng [10] examined the failure
mechanism of FRP confined concrete. They reported that the failure of FRP confined concrete was
dominated by the rupture of FRP at an average stress much smaller than the ultimate tensile stress
obtained from the FRP flat coupon tensile test. Turgay et al. [12] developed a stress-strain
confinement model to predict the ultimate comrpessive strength and strain for FRP confined concrete.
Berthet et al. [13] investigated the compressive behaviour of concrete wrapped by E-glass FRP
composite jackets with concrete compressive strength varying from 20 MPa to 200 MPa. The results
showed that the confinement effect of FRP on normal strength concrete was larger than that on high
strength concrete.
Nowadays FRP materials are widely accepted in the practical infrastructure construction industry
such as highway bridge decks and piles. Fam et al. [14] reported the construction details and field
tests of precast CFFT piles which were used for the first time in the construction of the Route 40
highway bridge over the Nottaway River in the United States.
Although FRP composites have a promising future as construction materials, the wider application of
FRP in structures is limited mainly by its high initial cost and the concern that the non-yielding
characteristics of FRP could result in wide cracks in confined concrete after the rupture of FRP. This
may lead to sudden brittle failure of FRP confined concrete structures [15, 16].
Nowadays the increasing of environmental consciousness promotes a rapid development in bio-
composites with high mechanical performance. Use of bio-fibres to replace synthetic carbon/glass
fibres as reinforcement has gained popularity in engineering applications [17-19]. Compared with
glass and carbon fibres, natural fibres are more cost effective and abundantly available, and have high
specific strength and stiffness [20, 21]. Among natural fibres, flax, hemp, jute and coir are the most
popular reinforcement materials in composites due to their good mechanical properties and availability
[22]. Polymer matrix reinforced by woven fabric is probably the form of composites used most
commonly in structural applications such as aircrafts, boats and automobiles. Test by Assarar et al.
[22] compared the tensile properties of flax fabric reinforced composites with glass fabric reinforced
composites (GFRP). They confirmed that the tensile stress and strain of flax fabric reinforced epoxy
composites were close to GFRP composites. The flax composites can be recommended in structural
application.
Natural fibres are also considered in the cementitious matrix to increase concrete tensile and flexural
strengths, increase toughness, impact resistance and fracture energy [23]. Generally, natural fibres
are cellulose materials with relatively lower specific densities. They can be used to decrease concrete
weight when they are at high fibre volumes. They can be optimised in the concrete to design a
construction material with high performance–to-cost ratio [24].
Coir fibre, as reinforcement material in the cementitious matrix, has been investigated by many
researchers because coir fibres are most ductile among natural fibres, nearly cost-free and abundantly
available worldwide. Satyanarayana et al. [25] and Munawar et al. [26] presented stress-strain curves
for 12 natural fibres confirming the higher ductility of coir fibre up to 24 % and 39 %, respectively. For
other natural fibres, their strains at failure range from 3 % to 6 %. Baruah and Talukdar [27] analysed
the mechanical properties of coir fibre reinforced concrete (CFRC) with different volume fractions of
0.5 %, 1 % and 2 % of concrete, the fibre length is 4 cm. The study showed that the compressive,
splitting tensile and shear strengths were increased with an increase in fibre volume fraction. The
CFRC with 2 % coir fibre possessed the best mechanical properties, whose compressive, splitting

2


tensile and shear strengths were increased up to 13.7 %, 22.9 % and 32.7 %, respectively, compared
to those of PC. Experiments by Ali et al. [28] showed that concrete compressive strength was
increased 9 % by an addition of 1 % coir fibre (by weight of cement). In the splitting tensile test, plain
concrete specimens were broken into two halves without contact, while for CFRC, the two halves were
still held by the coir fibre as a whole.
In this study, novel flax FRP (FFRP) tube confined coir fibre reinforced concrete (CFRC) structure
was investigated. This new system consists of a FFRP tube and a CFRC core. In this system, the
relatively cheaper flax fibre as reinforcement material of FRP tube to confine concrete for enhancing
concrete compressive strength and ductility. Coir fibre in the cementitious matrix to further increase
concrete compressive strength and control concrete crack patterns, as the non-yielding behaviour of
FRP materials could result in brittle failure of the concrete core. The behaviour of FFRP confined PC
and FFRP confined CFRC specimens under axial compression was investigated.

2 EXPERIMENTS
2.1 FFRP tubes

The reinforcement material of the flax FRP composites is the bidirectional woven flax fabric. The
Epoxy system used is the SP High Modulus Ampreg 22 resin and Ampreg 22 slow hardener. The
tensile strength and modulus of the resin is 70 MPa and 3.7 GPa, and strain to failure and linear
shrinkage is 3.0 and 1.7 %, respectively. The FFRP tubes were fabricated using the hand lay-up
process at the Centre for Advanced Composites Materials (CACM) at the University of Auckland.
o
Fabric fibre orientation was at 90 from the axial direction of the tube. Composites tensile properties
were determined by flat coupon tensile test on Instron 5567 machine according to ASTM D3039 [29]
and their flexural properties were determined on the Instron 5567 machine in accordance with ASTM
D790 [30]. The mechanical properties of the FFRP composites are listed in Table 1. Fibre volume
fraction is the ratio of fibre volume divided by the total volume of the composite.

Table 1: Mechanical properties of flax FRP composites
No. of flax FRP Tensile Tensile Tensile Flexural Flexural Fibre
fabric layers thickness strength Modulus Strain strength Modulus volume
(mm) (MPa) (GPa) (%) (MPa) (GPa) fraction (%)
2 2.65 102 5.0 3.6 103 5.9 53.8

4 5.30 125 9.2 4.4 128 8.5 55.7

The fabrication process of flax FRP tubes has nine steps: (1) Cutting: Flax fabrics were cut into a
specified size. The length of a piece was equal to the perimeter of a concrete cylinder (100 mm in
diameter), with an overlap of 100 mm. A width is 200 mm as the cylinder height. (2) Surface
preparation: Hollow aluminium tube mould was wrapped with a thin release film for easy demoulding
of the tube. (3) Epoxy resin mixture: The Ampreg 22 resin and hardener were mixed with a ratio of
100:28 by mass. (4) Impregnation of flax fabrics: Fabric pieces were impregnated into the resin for 30
min. (5) Primer application: A coat of epoxy primer was applied to the release film surface to cure for
30 min. at the room temperature. (6) First fabric application: The first epoxy-impregnated fabric was
then applied. The prepregnated fabric was carefully rolled around the mould to insure good adhesion.
(7) Second fabric application: The second fabric layer was applied. This step was repeated for the
targeted layers. (8) Curing: After consolidation for 24 h at room temperature, the FFRP tube with the
o
mould was cured in an oven at 65 C for 7 h. (9) After curing, the tube was removed from the mould
with the help of a press machine.

3


2.2 Concrete specimens

A total 18 concrete cylinders were constructed: three PC and three CFRC specimens (100 mm in
diameter and 200 mm in height) as the control group, half of the 12 remaining cylinders were FFRP
confined PC and the other six are FFRP confined CFRC specimens, with 100 mm core diameter and
200 mm height. The matrix of the specimens prepared for this study is listed in Table 2. Two different
layer arrangements of FFRP tube were used: two layers and four layers (Figure 1).

Figure 1: Flax FRP tubes (a) flax fabrics, (b) FFRP tubes with mould, (c) demould and (d) FFRP tubes

Coir fibres were immersed in water for 6 h to remove dust. The washed fibres were rolled with a
radial toothed roller and then combed to divide the fibres smoothly and orientated them in one
o
direction using a steel comb. Next, the fibres were dried in an oven at 70 C for 24 h. Later, the fibres
were cut to length of 40 mm and a sieve was used to separate the very short fibres from the
designated fibres.

Figure 2: CFRC is poured in a FFRP tube

4


Table 2: Test matrix
Specimen No. of FFRP Core Height Tube
*
type specimens layers diameter (mm) (mm) thickness (mm)
PC 3 -- 100 200 --
CFRC 3 -- 100 200 --
2-FFRP-PC 3 2 100 200 2.65
4-FFRP-PC 3 4 100 200 5.30
2-FFRP-CFRC 3 2 100 200 2.65
4-FFRP-CFRC 3 4 100 200 5.30
In column *, 2- for 2-layer and 4- for 4-layer

Two batches of concrete were prepared. Both batches were designed as plain concrete with a 28-
day compressive strength of 25 MPa. The concrete mix design followed ACI Standard 211. 1 [31]. The
mix ratio by weight was cement: water: gravel: sand = 1: 0.58: 3.72: 2.37. For the second batch, coir
fibre was added during mixing. The coir fibre length is 40 mm and weight content is 1 % of concrete.
For each FFRP tube, one end was capped with a wooden plate. Then concrete was cast, poured,
compacted and cured in a standard curing water tank for 28 days. Both ends of FFRP specimens
were treated with high quality mortar to have a uniform surface bearing and then a blade was used to
cut the edges of the FFRP tube to avoid it from directly bearing the axial compression (Figure. 3).

Figure 3: Specimens (a) without and (b) with surface treatment

2.3 Experimental instruments

Compressive test was conducted to investigate the FFRP confinement effect on the concrete
specimens. For each cylinder, four strain gauges were used. Two strain gauges were mounted at the
mid-height of a cylinder aligned along the hoop direction to measure the hoop strain and two strain
gauges were mounted at the mid-height of a cylinder aligned along the axial compressive direction to
measure the axial strain, as displayed in Figure 4. An Avery-Dension test machine was used to
perform the compression test using stress control based on ASTM C39 [32]. Each sample was axially
compressed up to failure. Readings of the load, displacement, gauges and LVDTs were taken using a
data logging system and were stored in a computer.

5


Figure 4: Schematic of axial compression test

3 RESULTS AND DISCUSSION
3.1 Test results

'
The average static compressive properties of each concrete type are listed in Table 3. f co is the
'
compressive strength of unconfined concrete and f cc is the compressive strength of confined
concrete. Confinement effectiveness of FRP confined concrete is defined as compressive strength of
'
the confined concrete f cc divided by the corresponding compressive strength of unconfined
'
concrete f co . ε co and ε cc are the ultimate axial strain for unconfined concrete and FFRP confined
concrete with respect to the ultimate strength, respectively. ε h.rup is the hoop strain at the rupture of
FFRP. Table 3 shows that the coir fibre slightly decreased the compressive strength of CFRC. This
may attributable to the non-uniform distribution of the fibres in the concrete which leads to voids
resulting in decreased strength. However, coir fibre enhanced the ultimate axial compressive strain to
0.0047, compared to that of 0.0019 for plain concrete. This fact indicated that the post-cracking
toughness of CFRC is much higher than that of PC, and more energy is dissipated to damage the
CFRC. The increase of toughness is believed attributable to the fibre bridging effect which resists
further opening of initial cracks in the concrete.

Table 3. Test results for all the specimens
Properties PC CFRC 2 layer 4 layer 2 layer 4 layer
FFRP-PC FFRP-PC FFRP-CFRC FFRP-CFRC
' ' 25.3 ± 1.6 * 23.9 ± 1.0 * 38.7 ± 1.4 50.4 ± 2.7 33.2 ± 1.8 48.9 ± 2.2
f co or f cc (MPa)

ε co or ε cc (%) 0.19 ± 0.02 * 0.47 ± 0.05 * 1.5 ± 0.2 1.9 ± 0.1 1.5 ± 0.1 2.2 ± 0.2
-- -- 2.6 ± 0.2 4.5 ± 0.1 3.5 ± 0.2 4.2 ± 0.1
ε h.rup (%)
' ' -- -- 1.53 1.99 1.39 2.05
f cc / f co
-- -- 7.89 10.47 2.96 4.36
ε cc / ε co
' '
The * values were used for calculating the f cc / f co and ε cc / ε co for FFRP tube confined PC and CFRC

6


For both PC and CFRC, FFRP tube confinement enhanced the ultimate strength and axial strain
remarkably. Both structural ductility and carrying capacity increased noticeably with the thickness of
FFRP tube. For confined PC, the average confinement effectiveness and axial strain ratio of two
layers of FFRP is 1.53 and 789 %, and of four layers of FFRP is 1.99 and 1047 %. For confined
CFRC, the average confinement effectiveness and axial strain ratio by two layers and four layers is
1.39 and 296 %, and 2.05 and 436 %, respectively. The results confirmed that the effect of
confinement on CFRC is larger than that on PC for concrete confined by 4-layer FFRP. This may be
attributable to the non-uniform distribution of fibres in the concrete which leads to voids resulting in
strength reduction.
The average ultimate axial strains for confined PC and CFRC with 2-layer FFRP are both 1.5 %, and
with 4-layer FFRP are 1.9 % and 2.2 %, respectively. This indicates that the effect of coir fibre on the
ultimate strain of FFRP confined concrete is insignificant than that on unconfined one. The possible
reason is that the third linear region (see Figure 5) in the stress-strain curve of FFRP confined
concrete is mainly dominated by the behaviour of FFRP tube.
As for hoop strain, it was clear that the coir fibre significantly increased the hoop strains of concrete
due to the fibre bridging effect. For FFRP confined PC, the growth of tube thickness increased the
hoop strain remarkably, compared to that on the confined CFRC. In general, the effect of FFRP tube
on increasing the hoop strain is larger than that on axial strain, for both confined PC and CFRC.

3.2 Stress-strain relationships
All previous studies [1-12] on FRP confined concrete displayed that, subjected to an axial
compressive load, FRP confined concretes behave bi-linearly, two linear regions connected by a
transition zone. The stress-strain curve of 4 layer FFRP tube confined PC is presented in Figure 5. In
general, the curves of FFRP confined PC are similar to those of FFRP confined CFRC, which are also
similar to those of G/CFRP confined concrete.

Figure 5: Stress-strain curves: FFRP confined PC and FFRP confined CFRC

Stress-strain curves obtained from this study can be divided approximately into three zones. In the
first purely linear region, the stress-strain behaviour of both FFRP confined PC and CFRC specimen is
similar to their corresponding unconfined PC and CFRC. In this region the applied axial stress is low,
lateral expansion of confined PC and CFRC is inconsiderable and confinement of FFRP tube is not
activated. When the applied stress approaches the ultimate strength of unconfined PC or CFRC, the
curve enters the second nonlinear transition region where considerable micro-cracks are propagated
in concrete and the lateral expansion increased. With the growth of micro-cracks, the tube starts to

7


confine the concrete core and counteracts the stiffness degradation of the concrete. The third
approximately linear region is mainly dominated by the structural behaviour of FFRP composites
where the tube is fully activated to confine the core, leading to a considerable enhance in compressive
strength and ductility of concrete when the core is subjected to tri-axial compression. When axial
stress increases, FFRP tube hoop tensile stress also increases. Once this hoop stress exceeds the
ultimate tensile strength of FFRP tube, failure of the first layer starts, subjected to sustained loading, a
sequential layer failure will occur, leading to a total structural failure.

3.3 Failure mode
Figure 6(a) displays that failure of PC is more severe than that of CFRC. It was observed that the
crack widths of PC are clearly larger than those in CFRC; also some parts of concrete are crushed
and spalled. In contrast, the cracks in CFRC are held by the coir fibres. The coir fibres bridge the
macro-cracks in the concrete and provides an effective secondary reinforcement for crack width
control, thus the macro-cracks are prevented and blocked.
In Figures 6(b) and 6(c), failure modes of FFRP confined PC and CFRC are presented. 2 FFRP-PC
and 4 FFRP-PC stands for 2 layer and 4 layer FFRP tube confined plain concrete, respectively. 2
FFRP-CFRC and 4 FFRP-CFRC stands for 2 layer and 4 layer FFRP tube confined coir fibre
reinforced concrete, respectively. For all the confined PC and CFRC, the specimens failed by sudden
rupture of FFRP tube accompanied by a heavy popping noise. The single and straight fracture crack in
o
the tube parallels to the axial stress direction. This linear crack is attributed to the 90 orientation of the
flax fabric in the tube, i.e., hoop direction. The tube crack location is strongly dependent on the
development of concrete cracks.

8


Figure 6: Failure mode: (a) PC vs. CFRC, (b) FFRP confined PC and CFRC, and (c) FFRP confined
PC and CFRC after removing tubes

FFRP tubes separated from the concrete cores after failure are given in Figure 6(c). The tubes were
removed from the cores with ease. This indicates that the tubes have no attachment to the core. All
the specimens possessed cracks on the concrete, which implies that the concrete has already failed
before the rupture of the tube. Therefore, once the concrete core was cracked, the FFRP would be
activated gradually due to the lateral expansion caused by the gradual crushing and compaction of the
concrete, and FRP tube dominated the stress-strain behaviour in the third linear region in Figure 5.
However, it is clear that PC specimens confined by FFRP have larger cracks width compared to the
confined CFRC specimens. The PC core has been crushed and spalled but the CFRC only had
cracks. Thus, the addition of coir fibre in FRP confined concrete can effectively reduce concrete wide
cracks after failure. This is important for changing the failure mode of FRP confined plain concrete due
to the non-yielding behaviour of FRPs.

4 CONCLUSIONS
The compressive behaviour of flax FRP (FFRP) tube confined plain concrete (PC) and coir fibre
reinforced concrete (FFRP confined CFRC) was studied. The study reveals:
• The axial stress-strain behaviour of flax FRP confined plain concrete and coir fibre reinforced
concrete is bilinear.
• The use of coir fibre increased the ultimate axial strain of the plain concrete significantly, from
0.0019 to 0.0047.
• For both unconfined and confined concrete, coir fibre can prevent and control the macro-cracks of
concrete effectively. The coir fibre can be used to reduce the wider cracks in FRP confined plain
concrete core.
• FFRP enhanced the compressive strength and ductility of PC and CFRC considerably, as well as
resulting in large energy absorption capacity. As for PC, the confinement effectiveness and
ultimate axial strain ratio are 1.53 and 789 % for 2-layer FFRP tube and 1.99 and 1047 % for 4-
layer FFRP tube. As for CFRC, these values are 1.39 and 296 % for 2 layer-FFRP tubes and 2.05
and 4.36 % for 4 layer-FFRP tubes.
• The effect of FFRP confinement on the hoop strain enhancement is greater than that on the axial
strain of both FFRP confined PC and CFRC.
• The failure mode of flax FRP confined concrete is dominated by the rupture of flax FRP in the
hoop directly when the hoop tensile strength exceeds the tensile strength of FFRP tube.

9


REFERENCES

[1] A. Mirmiran and M. Shahawy. “Behavior of concrete columns confined by fiber composites”. J
Struct Eng ASCE, 23, 583-590 (1997).

[2] M.S. Samaan. “An analytical and experimental investigation of concrete filled fiber reinforced
plastics (FRP) tubes”. Ph.D Thesis, University of Central Florida, Orlando, Florida (1997).

[3] A. Mirmiran, M. Shahawy, M. Samaan, H.E. Echary, J.C. Mastrapa and O. Pico. “Effect of column
parameters on FRP-confined concrete”. J Compos Constr ASCE, 2,175-185 (1998).

[4] A. Fam and S.H. Rizkalla. “Confinement model for axailly loaded concrete confined by circular
fibre-reinforced polymer tube”. ACI Struct J, 98, 451-461 (2001).

[5] H.M.H. Mohamed. Axial and flexural behaviour of reinforced concrete-filled FRP tubes:
Experimental and theoretical studies. Ph.D Thesis, University of Sherbrooke, Sherbrooke (2010).

[6] A. Fam and S. Rizkalla. “Flexural behavior of concrete-filled fiber-reinforced polymer circular
tubes”. J Compos Constr ASCE, 6, 123-132 (2002).

[7] M.N. Fardis and H.H. Khalili. “FRP-encased concrete as a structural material”. Mag Concrete Res,
34,191-202 (1983).

[8] A. Mirmiran and M. Shahawy. “A new concrete-filled hollow FRP composite column”. Composites:
Part B, 27, 263-268 (1995).

[9] Y. Xiao and H. Wu. “Compressive behaviour of concrete confined by carbon fiber composites
jackets”. J Mater Civil Eng ASCE, 12, 139-146 (2000).

[10] L. Lam and J.G. Teng. “Design-oriented stress–strain model for FRP-confined concrete”. Constr
Build Mater, 17, 471-489 (2003).

[11] J. Berthet, E. Ferrier and P. Hamelin. “Compressive behavior of concrete externally confined by
composite jackets Part B: modeling”. Constr Build Mater, 20, 338-347 (2006).

[12] T. Turgay, H.O. Köksal, Z. Polat and C. Karakoc. “Stress–strain model for concrete confined with
CFRP jackets”. Mater & Des,30, 3243-3251 (2009).

[13] J. Berthet, E. Ferrier and P. Hamelin. “Compressive behavior of concrete externally confined by
composite jackets Part A: experimental study”. Constr Build Mater, 19, 338-347 (2005).

[14] A. Fam, M.P. Pando, G. Filz and S. Rizkalla. “Precast piles for route 40 bridge in Virginia using
concrete filled FRP tubes”. PCI J, 48, 31-40 (2003).

[15] US-FHWA. U.S. Department of Transportation Federal Highway Administration. 2011. Web site::
http://www.fhwa.dot.gov/bridge/frp/deckproj.cfm

[16] C.E. Bakis, L.C. Bank, V.L. Brown, E. Cosenza, J.F. Davalos, J.J. Lesko, A. Machida, S.H.
Rizkalla and T.C. Triantafillou. “Fiber-reinforced polymer composites for construction-State-of-the-art
review”. J Compos Constr ASCE, 6, 369-384 (2002).

10


[17] P. Kushwaha and R. Kumar. “Enhanced mechanical strength of BFRP composite using modified
bamboos”. J Reinf Plast Comp, 28, 2851-2859 (2008).

[18] E. Bodros, I. Pillin, N. Montrelay and C. Baley. “Could biopolymers reinforced by randomly
scattered flax fibre be used in structural applications?” Compos Sci Technol, 67, 462-470 (2007).

[19] P. Bordes, E. Pollet and L. Averous. “Nano-biocomposites: Biodegradable polyester/nanoclay
systems”. Progr in Polym Sci, 34, 125-155 (2009).

[20] F. Corrales, F. Vilaseca, M. Llop, J. Girones, J. Mendez and P. Mutje. “Chemical modification of
jute fibers for the production of green-composites”. J Hazard Mater, 144, 730-735 (2007).

[21] P. Herrerafranco, A. Valadezgonzalez. “A study of the mechanical properties of short natural-fiber
reinforced composites”. Composites: Part B, 36, 597–608 (2005).

[22] M. Assarar, D. Scida, A. El Mahi, C. Poilân and R. Ayad. “Influence of water ageing on
mechanical properties and damage events of two reinforced composite materials:Flax–fibres and
glass–fibres”. Mater & Des, 32, 788-795 (2012).

[23] P.N. Balaguru, S.P. Shah. Fiber-reinforced cement composites. McGraw-Hill (1992).

[24] K.D. Vinson and J.I. Dniel. “Specialty cellulose fibres for cement reinforcement. In: Thin section
fibre reinforced concrete and ferrocement”, SP-124. Detroit: ACI, 1-18 (1990).

[25] K.G. Satyanarayana, K. Sukumaran, R.S. Mukherjee, C. Pavithran and S.G.K. PiUai. “Natural
fibre-polymer composites”. Cement Concrete Comp, 12, 117-136 (1990).

[26] S.S. Munawar, K. Umemura and S. Kawai. “Characterization of the morphological, physical, and
mechanical properties of seven nonwood plant fiber bundles”. Journal of Wood Science , 53, 108-113
(2006).

[27] P. Baruah and S. Talukdar. “A comparative study of compressive, flexural, tensile and shear
strength of concrete with fibres of different origins”. Indian Concrete J, 81, 17-24 (2006).

[28] M. Ali, A. Liu, H. Sou and N. Chouw. Effect of fibre content on dynamic properties of coir fibre
reinforced concrete beams. In: New Zealand Society for Earthquake Engineering (NZSEE)
Conference Proceedings. Wellington, New Zealand, March 26-28 (2010).

[29] ASTM. Standard test mothods for tensile properties of polymer matrix composite materials. ASTM
D3039 (2008).

[30] ASTM. Standard test mothods for flexural properties of unreinforced and reinforced plastics and
eletrical insulating materials. ASTM D790 (2010).

[31] ACI 211. 1-91. Standard practice for selecting proportions for normal, heavyweight, and mass
concrete. American Concrete Institute, Farmington Hills, Michigan (1991).

[32] ASTM. Standard test mothods for compressive strength of cylindrical concrete specimens. ASTM
C39 (2010).

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COMPRESSIVE BEHAVIOUR OF FLAX FRP TUBE CONFINED COIR FIBRE REINFORCED CONCRETE

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