study on structure, extraction and … journal of advances in mechanical and civil engineering,...

International Journal of Advances in Mechanical and Civil Engineering, ISSN: 2394-2827 Volume-3, Issue-4, Aug.-2016

Study on Structure, Extraction and Prevention of Bamboo Fiber as Strength Enhancer in Concrete

17

STUDY ON STRUCTURE, EXTRACTION AND PREVENTION OF BAMBOO FIBER AS STRENGTH ENHANCER IN CONCRETE

1KAVITHA.S, 2T.FELIX KALA

1Research scholar, Dr.M.G.R Educational Research & Institute university, Chennai ,India 2Profeesor & Hod, Dr.M.G.R Educational Research &Institute university, Chennai ,India

E-mail: [email protected], [email protected] Abstract— In conventional concrete, micro cracks develop before structure is loaded because of drying shrinkage and other causes of volume change. So after addition of fibers it helps to develop the tensile and torsional strength and excellent permeability and frost resistance. Bamboo fibers are focused as one of substitution for natural plant fibers having many advantages such as low cost, low density, ecologically friendly, sustainability and biodegradability. Present study is made to understand the structure ,Preservative treatment, behavior of bamboo fibers by SEM analysis and to develop different methods of extracting bamboo fibers by using mechanical extracting, steam-explosion and alkaline-treatment techniques to use as a strength enhancer in the concrete. The studies has proved that the alkaline-treatment was better than the steam-explosion method to extract bamboo fibers as well for mechanically extracted fibers as reinforcement for green composites, where two years or older raw bamboo (younger than four years old) was immersed in 1% NaOH solution for 10 hours.

Index Terms— Structure, Bamboo Fibers, Alkaline Treatment, Steam Explosion, Mechanical Extraction.

I. INTRODUCTION A fibre is a small discrete reinforcing material produced from various materials like steel, plastic, glass, carbon and natural materials in various shapes and sizes. Bamboo is primarily a type of giant grass with woody stems. The stems are called “shoots” when the plant is young and “culms” when the plant is mature. Each bamboo plant consists of two parts – the “Culm”/stem that grows above the ground and the underground “rhizome” that bears the roots of the plant. “A single bamboo clump can produce up to 15 kilometers of usable pole (up to 30 cm in diameter) in its lifetime.” Bamboo in comparison with other natural fibers is eco friendly with high growth rate and fixing the carbon dioxide of atmosphere, which makes it the most important plant fibers. It is found that more than 1000 species of bamboo and around 70 genera grow naturally in diverse climates, especially in Asia and South America abundantly. Bamboo has several advantages such as light weight, high strength, stiffness, biodegradability, and even its roots and leaves keep the soil together and protect it against the sun respectively. These properties are caused that bamboo to be used traditionally for manufacturing of living tools. Beside the massive utilization of bamboo in building construction and living tools, it also can be used as reinforced composite materials base on extracting appropriate fibers in a controlled manner. However, there are some problems that provide barriers to a broad usage of bamboo fibers. These are as follow: • Moisture resistance of bamboo is low and its mechanical and chemical properties are inadequate at the fundamental stage. • The existing extraction process of the fibers from bamboo Culm is not appropriate for industrial and commercial production.

II. BAMBOO STRUCTURE Bamboo culms are hollow, and every Culm from inner side is divided by several diaphragms which are seen as rings on the outside. The part between two rings is called “Internode” where branches grow. Distance between each node varies and it depends on the type of the species. The microstructure of a bamboo Culm consists of many vascular bundles which are embedded in parenchyma tissue and distributed through the wall thickness. Parenchyma tissue only keeps the vascular bundles in the longitudinal direction. The number of vascular bundles is highly concentrated close to the outside of the bamboo Culm wall, and this amount reduced on the inside. They involve vessels, sclerenchyma cells, fiber strand and sieve tubes with companion cells. The fiber strand consists of many elementary fibers with the shape of hexagonal and pentagonal, where Nano-fibrils are aligned and bounded together with lignin and hemi-cellulose. The strength of a bamboo Culm is defined by its vascular bundles. Therefore it is essential to use a suitable method to separate the parenchyma tissue from fiber strands and vascular bundles without any destructive effect on the extracted fibers. The different ages of bamboo as shown in fig 1.the structure of bamboo Culm as shown in fig 2 and fig3,4,5 shows the images of scanning electron micro scoping of bamboo fibers of different diameters of fibers 700microns,1.56mm and 1.244mm respectively.

Fig.1 Different ages of raw bamboo



18

Fig.2 Structure of bamboo culm

Fig.3 scanning electron microscoping image of bamboo fibre

diameter 700microns


diameter 1.156mm


diameter 1.24mm III PRESERVATION AND TREATMENT As bamboo has less natural durability it requires chemical treatment for longer life. Bamboos have low natural durability (1 to 3 years) against attacks by fungi and insects. They are very difficult to be treated by normal preservative methods in dry condition since their outer and to some extent inner membranes are impermeable to liquids. The treatment of bamboo is, therefore, best carried out in green conditions. Types of prevention Coal Tar Creosote:

• This is a fraction of coal tar distillate with a boiling point range above 200°C and is widely used admixed with fuel oil in the ratio of 50:50.

• The fuel oil ensures stability to creosote against evaporation and bleeding from the treated

• bamboos. • Creosote has high performance; it is

non-corrosive and provides good protection from termites.

• Boric Acid Borax: • This has been used successfully against lyctus

borers. A mixture of 2:5 percent of each is found

• more suitable. IV. EXTRACTION METHODS There is a limited knowledge regarding bamboo fiber extraction, only a few investigations have been done with different processes to define the mechanical properties and the usage of bamboo fiber as reinforced polymer composite. In more scientific studies in order to extract fibers from bamboo Culm firstly, the diaphragm and node has been removed, and then the hollow portions have been used for processing. Subsequently, various methods have been used to



19

extract bamboo fibers based on their application in the industries. These processes are classified as chemical, mechanical and combination of mechanical and chemical. The usual methods to extract fiber are follows: 1. The mechanical extraction method : Raw bamboo (2~8months) was first longitudinal cleaved into small slabs by the roller crusher. The pin-roller looser was used to extract small slabs into coarse fibers before removing fat by the boiler at 900 C for 10 hours. Then, coarse fibers were put into the dehydrator and finally dried in the Rotary dryer. the process is as shown in figure 6,7,8 and 9

Fig.6 longitudial striped bamboo under roller

Fig.7 longitudial striped bamboo under roller

Fig.8 longitudial striped and rolled bamboo after rolling

Fig.9 longitudial striped bamboo fibres

2. The alkali-treated method : Nodes of raw bamboo (2~4 four years old) were first removed and remaining parts were cleaved in longitudinal direction to thin slabs with 20-30 cm in length and 2-3 mm in thickness by the slicer. These thin slabs were then immersed in NaOH solution at 700 C for 10 hours. The concentrations of NaOH were 1%, 2%, 3%. The 1% concentration of NaOH was selected in this study due to the higher mechanical properties of fibers with 1% than other fibers treated with 2% and 3% of NaOH . The roller looser was used to extract alkali treated slabs into small fibers. Finally, they were washed with fresh water to neutralize, and dried in the oven for 24 hours at 1050 C. Fig 10 shows the bamboo fibers in solution.

Fig.10 Bamboo fibres in solution

3. The steam-explosion method: Raw bamboo (2~4 four years old) was first cut into bamboo culms with 70-80cm in length by saw machine, and put into an autoclave with over-heated steam at 1750 C and 0.7-0.8 MPa for 60 minutes. Then, the steam was suddenly released for 5 minutes and the cycles of sudden-steam release were continuously repeated for 9 times to assure the complete facture of cell walls. Finally, they were washed in hot water with addition of soap at 90-950 C for 15 minutes to remove ash and dried in the oven for 24 hours at 1050 C.



20

CONCLUSION Bamboo fiber has several advantages over other plant natural fibers such as high growth rate, strength, and fixing the carbon dioxide. It also can be compared with glass fibre because of its light weight, biodegradability, and low cost. The following conclusions has drawn The structure ,Preservative treatment, behavior

of bamboo fibers by SEM analysis has been studied

Different methods of extracting bamboo fibers by using mechanical extracting, steam-explosion and alkaline-treatment techniques to use as a strength enhancer in the concrete have been developed.

The studies has proved that the alkaline-treatment was better than the steam-explosion method to extract bamboo fibers as well for mechanically extracted fibers as reinforcement for green composites, where two years or older raw bamboo (younger than four years old) was immersed in 1% NaOH solution for 10 hours.

Several methods and adhesions have been used to improve the mechanical properties of bamboo fibers as reinforced composite. This can help to comprehend that bamboo fiber and bamboo fiber reinforced composite have ability to be used in more applications.

Therefore, there is a great interest in using bamboo fiber as a reinforced composite material in different applications.

REFERENCES

[1] [1] M. J. John and S. Thomas, "Biofibres and biocomposites," Carbohydrate Polymers, vol. 71, pp. 343-364, 2008.

[2] [2] H. P. S. A. K. M. Jawaid, "Cellulosic/synthetic fiber reinforced polymer hybrid composites: A review," Carbohydrate Polymers vol. 86, pp. 1-18, 2011.

[3] [3] D. Eldridge, "Flax weaves its way into cars and aircraft," European Plastics News, pp. 1-2, March 28 2013.

[4] [4] P. McMullen, "Fiber/resin composites for aircraft primary structures: a short history, 1936–1984," Composites, vol. 15, pp. 222-230, 1984.

[5] [5] S. V. Joshi, L. Drzal, A. Mohanty, and S. Arora, "Are natural fiber composites environmentally superior to glass fiber reinforced composites?," Composites Part A: Applied science and manufacturing, vol. 35, pp. 371-376, 2004.

[6] [6] P. Wambua, J. Ivens, and I. Verpoest, "Natural fibers: can they replace glass in fibre reinforced plastics?," composites science and technology, vol. 63, pp. 1259-1264, 2003.

[7] [7] M. F. C. Loretta Gratani, Laura Varone, Giuseppe Fabrini, Elenora Digiulio, "Growth pattern and photosynthetic activity of different bamboo species growing in the Botanical Garden of Rome " Flora - Morphology, Distribution, Functional Ecology of Plants vol. 203, pp. 77-84, 2008.

[8] [8] H. Abdul Khalil, I. Bhat, M. Jawaid, A. Zaidon, D. Hermawan, and Y. Hadi, "Bamboo fibre reinforced biocomposites: A review," Materials & Design, vol. 42, pp. 353-368, 2012.

[9] [9] J. J. Janssen, Designing and building with bamboo: International Network for Bamboo and Rattan China, 2000. [10] X.-J. X. F.G. Shin, W.-P.Zheng, M. W.Yipp, "Analyses of the mechanical properties and microstructure of bamboo-epoxy composites," Journal of Materials Science, vol. 24, pp. 3483-3490, 1989.

[10] [10]A. Athijayamani, M. Thiruchitrambalam, U. Natarajan, & B. Pazhanivel. (2009). Effect of moisture absorption on the mechanical properties of randomly oriented natural fibers/polyester hybrid composite. Materials Science and Engineering A, 517, 344-353. http://dx.doi.org/10.1016/j.msea.2009.04.027.

study on structure, extraction and … journal of advances in mechanical and civil engineering,...

Documents