• Advanced Composite Materials
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• v.18 no.3
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• pp.197-208
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• 2009

Changes occurring in jute and coir fiber composites with 2-8% concentration of a NaOH treatment for 24 h were investigated, respectively, for void content, microscopy images, mechanical properties and water absorption. The jute and coir fibers were vacuum dried before molding composite specimens. Mechanical properties indicated good adhesion between natural fibers and PP. Jute fibers, when alkali-treated with 2% concentration for 24 h, showed best improvement in tensile strength by 40% and modulus by 9%, respectively, while coir fibers, when alkali-treated with 6% concentration for 24 h, showed best improvement in tensile strengths by 62% and modulus by 17%, respectively. With 2% concentration of alkali-treatments, the elongation of jute and coir composites reached 8% and 13.5%, respectively. Moisture absorption for jute and coir composites are 50% and 60% lower than untreated fiber composites, respectively.

• Fibers and Polymers
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• v.7 no.3
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• pp.286-294
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• 2006

This study has examined the flexural properties of natural and chemically modified coir fiber reinforced cementitious composites (CFRCC). Coir fibers of two different average lengths were used, and the longer coir fibers were also treated with a 1% NaOH solution for comparison. The fibers were combined with cementitious materials and chemical agents (dispersant, defoamer or wetting agent) to form CFRCC. The flexural properties of the composites, including elastic stress, flexural strength, toughness and toughness index, were measured. The effects of fiber treatments, addition of chemical agents and accelerated ageing of composites on the composites' flexural properties were examined. The results showed that the CFRCC samples were 5-12 % lighter than the conventional mortar, and that the addition of coir fibers improved the flexural strength of the CFRCC materials. Toughness and toughness index, which were associated with the work of fracture, were increased more than ten times. For the alkalized long coir fiber composites, a higher immediate and long-term toughness index was achieved. SEM microstructure images revealed improved physicochemical bonding in the treated CFRCC.

• Geomechanics and Engineering
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• v.2 no.1
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• pp.19-28
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• 2010

This paper describes the compaction and strength behavior of black cotton soil (BC soil) reinforced with coir fibers. Coir used in this study is processed fiber from the husk of coconuts. BC soil reinforced with coir fiber shows only marginal increase in the strength of soil, inhibiting its use for ground improvement. In order to further increase the strength of the soil-coir fiber combination, optimum percentage of 4% of lime is added. The effect of aspect ratio, percentage fiber on the behavior of the composite soil specimen with curing is isolated and studied. It is found that strength properties of optimum combination of BC soil-lime specimens reinforced with coir fibers is appreciably better than untreated BC soil or BC soil alone with coir fiber. Lime treatment in BC soil improves strength but it imparts brittleness in soil specimen. BC soil treated with 4% lime and reinforced with coir fiber shows ductility behavior before and after failure. An optimum fiber content of 1% (by weight) with aspect ratio of 20 for fiber was recommended for strengthening BC soil.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.115-127
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• 2014

Addition of fibers in cement or cement concrete may be of current interest, but this is not a new idea or concept. Fibers of any material and shape play an important role in improving the strength and deformation characteristics of the cement matrix in which they are incorporated. The new concept and technology reveal that the engineering advantages of adding fibers in concrete may improve the fracture toughness, fatigue resistance, impact resistance, flexural strength, compressive strength, thermal crack resistance, rebound loss, and so on. The magnitude of the improvement depends upon both the amount and the type of fibers used. In this paper, locally available waste fibers such as coir fibers, sisal fibers and polypropylene fibers have incorporated in concrete with varying percentages and l/d ratio and their effect on compressive, split, flexural, bond and impact resistance have been reported.

• Journal of the Korean Wood Science and Technology
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• v.35 no.2
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• pp.9-15
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• 2007

A comparative study of the structure and organization of the primary and secondary walls in different types of tropical plant waste fibers was carried out using transmission electron microscopy (TEM). The thickness of each layer was also measured using Image Analyzer. TEM micrographs haveconfirmed that cell wall structure of all six types of tropical plant waste fibers (empty fruit bunch, oil palm frond, oil palm trunk, coir, banana stem and pineapple leaf) has the same ultrastructure with wood fibre. The fibers consisted of middle lamella, primary and thick secondary wall with different thickness for different types of fibers. The secondary wall was differentiated into a $S_1$ layer, a unique multi-lamellae $S_2$ layer, and $S_3$ layer.

• Geomechanics and Engineering
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• v.16 no.6
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• pp.627-634
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• 2018

Soil stabilization is an essential engineering process to enhance the geotechnical properties of soils that are not suitable for construction purposes. This study focuses on using coconut coir, a natural fibre to enhance the soil properties. Lime, an activator is added to the reinforced soil to augment its shear strength and durability. An experimental investigation was conducted to demonstrate the effect of coconut coir fibers and lime on the consistency limits, compaction characteristics, unconfined compressive strength, stress-strain behaviour, subgrade strength and durability of the treated soil. The results of the study illustrate that lime stabilization and coir reinforcement improves the unconfined compressive strength, post peak failure strength, controls crack propagation and boosts the tensile strength of the soil. Coir reinforcement provides addition contact surface, improving the soil-fibre interaction and increasing the interlocking between fibre and soil and thereby improve strength. Optimum performance of soil is observed at 1.25% coir fibre inclusion. Coir being a natural product is prone to degradation and to increase the durability of the coir reinforced soil, lime is used. Lime stabilization favourably amends the geotechnical properties of the coir fibre reinforced soil.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.54-61
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• 2000

Covering rate, visual rating and sod development were evaluated under three natural fiber materials with Phragmites spp. when over a plastic sheet. The results were as follows. (1) The last covering rate was high on jute net, coir mat and on Miscanthus sacchariflorus, respectively while the early covering rate was high on coir mat and on Miscanthus sinensis+perennial ryegrass. (2) The early growth was good on perennial ryegrass but the covering rate gradually turned poor because of summer drought. (3) Sod was highly developed on Phragmites japonica, Miscanthus sacchariflorus and Miscanthus sinensis compared with other species and mixtures. (4) The covering rate and visual rating were high on natural fiber materials such as coir mat and jute net when compared with on natural fiber materials such as none treatment plots. (5) The natural fibers materials on Phragmites spp. and Miscanthus spp. were effect on sod establishment. Sod coir mat was highly established. (6) The carpet-type sod was best developed on the coir mat.

• Computers and Concrete
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• v.17 no.5
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• pp.597-612
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• 2016

The present work focuses on the use of coconut fiber in self compacting concrete. Self-Compacting Concrete (SCC) is a highly flowable, stable concrete which flows readily into place, filling formwork without any consolidation and without undergoing any significant segregation. Use of fibers in SCC bridge the cracks and enhance the performance of concrete by not allowing cracks to propagate. They contribute to an increased energy absorption compared to plain concrete. Coconut fiber has the highest toughness among all natural fibers. It is known that structures in the seismic prone areas are always under the influence of cyclic loading. To justify the importance of strengthening SCC beams with coir fiber, the present work has been undertaken. A comparison is made between cyclic and static loading of coconut fiber reinforced self compacting concrete (FRSCC) members. Using the test data obtained from the experiment, hysteresis loops were drawn and comparison of envelope curve, energy dissipation, stiffness degradation were made and important conclusions were draw to justify the use of coconut fiber in SCC.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.72-80
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• 2023

Melons, a rich source of vitamins and fibers, are commonly grown in the soil. Hydroponic cultivation could improve yield and quality of melon and selection of substrate volume and the kind of substrates is important for hydroponic cultivation of melons. This study investigated the effect on melon growth according to volume of granular rockwool and substrates of coir and rockwool slab. 'Geumsegye' melon (Cucumis melo L. cv. Geumsegye) was cultivated hydroponically according to volume of granular rockwool to 1.0, 1.5, 2.0, 3.0, and 4.0 L, and was also cultivated using coir and rockwool slabs. Logistic model was applied to estimate the growth characteristics of melons such as plant height, leaf length, leaf width, and the characteristics of fruit. The growth characteristics of melons were significantly increased at 4.0 L compared to those grown of 1.0 L volume of on granular rockwool, and the results were the highest in coir and rockwool slabs. Melons grown in rockwool slabs showed the largest fruit fresh weight, fruit length, and fruit width. During hydroponic cultivation, growth characteristics of melon appropriate at the 4.0 L volume of granular rockwool, and the highest at coir and rockwool slabs. This study provides a basis for understanding the effect of root zone environment to the growth characteristics and fruit quality of non-netted melon.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.279-284
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• 1999

Fiber drain(FD), which is made of organic fibers from jute and coir, has recently been used in several construction projects in the Southeast and East Asia region involving the soil improvement of reclamation fills overlying marine clay. FD is an environmentally friendly product that will naturally be biodegraded into soil after the completion of performance duration as a vertical drain. However, the conventional FD has limited and low-ranged discharge capacity compared to PVD. For this, in this study, the improvement of FD was attempted and new shaped FDs were evaluated by laboratory tests. A series of discharge capacity test was performed to investigate the functional applicability for several types of FDs.