Prof. Dr. AHMED ABD EL-MONEM KORASHY
Dr. MOHAMED ABD EL-SALAM ALY
1992
MASTER THESIS
PRESENTED BY
ENG. Nader Hassan Ibrahim
TITLED
STUDY OF THE APPROPRIATE MEANS OF UTILIZATION OF
BAMBOO IN STRUCTURES AND ENVIRONMENTAL INDUSTRIES
SUMMARY OF THE THESIS
At the time when Egypt and the whole Arab region suffer an acute shortage in structural materials, such as steel for reinforcement of concrete, steel section or limber for building, bamboo is available as renewable resource and as an alternative for use in housing as a structural material, as well as in wide span structure.
Besides, bamboo is considered to be an important raw material for many small-scale industries. These industries produce a wide variety of products used in countries where bamboo plantations are wide-spread, such as in south-east Asia . Some of these products find its way as consumer goods in many arabian countries. Besides, bamboo could be used for manufacture of pulp, for paper making and as a raw material for several chemical industries.
Several research centers and universities in the world direct their research activities to the study of the properties and merits of bamboo as raw material. This gave a strung push during the seventies and eighties to the studies devoted to the use of bamboo in many areas.
The final report of the conference, held in EL-Fayoum governorate in 1990, to study the potentialities of its development has focused attention on the use of bamboo as an endogenous raw material in the governorate. According to the publications of that conference bamboo was found to enjoy high tensile strength; tests were conducted in the laboratories of testing of materials in the Faculty of Engineering, Ain Shams University . This aroused interest in the study of local raw materials and the determination of its properties for use in different areas.
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Existence of bamboo and its traditional uses
Bamboo exists in wide regions in quite different weather conditions ranging from the tropical, semi-tropical to worm or even, cold weather where snow falls. More than 800 species of bamboo have been classified among about 3000 species of the family of grasses, to which bamboo belongs.
South-east Asia is famous for bamboo plantations. The annual production of bamboo there exceeds 10 million tons, mostly consumed in paper making, in small scale industries and structures, especially for housing. Bamboo fresh offshoots are also severed as food in several countries there.
Appearance of bamboo in Egypt and locations of its plantation
Bamboo appeared in Egypt as one of the ornamental grasses in Royal palaces during the reign of Mohammed Ali (1805-1845). There after, bamboo spread to other palaces and gardens in various governorates. At the present lime bamboo trees exist in most of the governorates of lower Egypt and EL-Fayoum, though in small numbers. But comparatively wide bamboo plantation could be found in Monoufia and Gharbia governorates.
Previous literature on bamboo in the whole world published in books or periodicals has been examined and presented
During the present work natural and mechanical properties of bamboo has been determined, The results could be presented as follows :
Natural properties
1.1. General description of bamboo culms
Both the wall thickness and the perimeter were found to be in inverse proportionality with the height, measured from earth. The length of culm between the successive nodes was found to increase from a minimum length at the bottom upward until it attains a maximum value; then it decreases again as we continue to ascend upward.
The length of bamboo culms subject to study was found to range from 10.75 to 23.10 meters: their diameter from 96 to 175 mm, whereas the wall thickness was found to vary from 15.1 to 23 mm and the number of culm portions between nodes from 35 to 60.
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1.2 The increase of moisture content with time
The average value of moisture content after submersion of bamboo specimens in water for 26 hours has amounted to 48.5% with a standard deviation of 9.12. No difference was noticed in the behavior of bamboo specimens, taken at different positions along the culms.
1.3 Determination of the moisture content in bamboo culm, naturally dried
The average value of moisture content in bamboo culms, naturally dried was found to be 12.32% with a standard deviation of 1.28. No difference was noticed for bamboo specimens, taken invarious locations along the culms or specimens having different wall thicknesses.
2. Mechinability of the bamboo culms
Relation between the value of cutting forces and cutting parameters in turning
* The value of the cutting force was found constant with variation of speed.
* The relation between the cutting force and feed could be expressed by an ascending curve, e.g., with increase of feed to twice its value, the cutting force increases by about 38%,
* The relationship between the cutting force with the depth of cut is linear; e.g. with increase of the depth of cut twice, the culling force increases to twice its value.
Comparisons were made with beech; spruce white, pitch pine, mahogany and oak species of wood. As far as mechinability indices are concerned the behavior of bamboo culm raw material was found to be similar to that of beech wood.
3. The mechanical properties
3.1 Loading of the bamboo culm as a simple beam
The modulus of rupture in bending was determined for bamboo culms, loaded as a simple beam. The value of the modulus of rupture in bending was found to fluctuate between 11.65 to 37.97 N/mm in case of the load acting in the mid section between two of the nodes and between 26.4 and 63.1 N/mm in case of the load acting in the plan of the node.
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3.2 Test of the bamboo culm on buckling
The bamboo culms were subjected to an axial load to determine the bauckling load. The values of compressive stresses a bamboo culm could withstand without buckling were determined. These values were found lo vary from 14.49 to 23.65 N/mm 2 for a slenderness ratio ranging from 23.57 to 75.6 N/mm 2 .
3.3 Determination of shear strength of bamboo culms parallel to fibers
The average values of failure stresses in bamboo culms specimens along fibers were determined. These values were found to fluctuate between 11.2 to 13.79 N/mm for specimens with different wall thickness.
3.4 Determination of the compressive strength or bamboo culm
It was found that the value of the compressive strength does not vary for specimens of different wall thickness or those taken between two nodes or taken so as to include node. The arrange value of compressive strength could be estimated as 50 N/mm 2
3.5 Determination of bending strength or the bamboo culm raw material
Test specimens for bending tests were prepared from bamboo culms according to ASTM 143-D. The modulus of rupture was determined for the bamboo culms raw material; it was found to vary from 162.1 to 179.3 N/mm 2 for specimens taken between two nodes and from 141.6 to 148.4 N/mm 2 for specimens including nodes. The bending strength was found lo be inversely proportional to the culm wall thickness.
3.6. Determination of the tensile strength of the bamboo culms row material
Specimens of bamboo culm raw material were prepared for tensile tests according to ASTM A 370. The value of the ultimate tensile strength was found to vary from 186.9; to 205 N/mm 2 for specimens taken between two nodes; and from 79 to 117 N/mm 2 for specimens including a node. Here also the ultimate tensile strength was found to be inversely proportional to the culms wall thickness.
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Future perspective of utilization of bamboo
The result of studies conducted to determine the natural and mechanical properties of bamboo together with the published literature in this concern show that bamboo culms grow with economic rates and enjoy external dimensions and mechanical properties (especially tensile and compressive strength) which recommend them for use as a substitute for metal sections In building of structures and in particular space trusses.
This suggests to continue work in future in two directions
The First, use of modern techniques and namely tissue culture for the increase of productivity, of bamboo, and the second, design of special joints to suit the use of bamboo culms in space trusses and development of means for transfer of forces between these joints and bamboo culms used in building of space trusses,
Besides, programs should be developed to transfer the skills needed for the processing of bamboo culms. This could be very helpful for the dissemination of small scale industries in rural and urban areas providing the low-cost labor opportunities and opening a real possibility for export of consumer goods made from bamboo as l local cheap raw material.
