These proceedings of the First International Conference on Modern Bamboo Structures ICBS, Changsha, China, October include the state-of-the-art on materials, design, analysis, testing, manufacturing, construction of modern bamboo structures. Modern Bamboo Structures will be essential for researchers, engineers and administrators involved in structural engineering, civil engineering, agriculture engineering, forestry, environmental engineering and urban development.
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CPD consists of any educational activity which helps to maintain and develop knowledge, problem-solving, and technical skills with the aim to provide better health care through higher standards. It could be through conference attendance, group discussion or directed reading to name just a few examples.
We provide a free online form to document your learning and a certificate for your records. Already read this title? Please accept our apologies for any inconvenience this may cause. Exclusive web offer for individuals. Proceedings of the First International Conference. Add to Wish List. Toggle navigation Additional Book Information. Description Table of Contents. Summary Bamboo materials are well available in the world. The editors are pleased and believe that these papers provide the-state-of-the-art about the research and applications of bamboo in structures. We believe the conference and the proceedings contribute to our knowledge towards the utilization of bamboo in the eco-friendly and sustainable construction.
The editors would like to thank all the participants and authors for their contribution. Particular appreciation is extended to the Hunan University for hosting the conference, and to the University of Southern California, the Oita University and the International Network for Bamboo and Rattan for co-organizing the Conference. It is my pleasure to have been invited to join the opening ceremony by Professor Xiao, chairman of the International Conference on Modern Bamboo Structures. Here, I would like to congratulate the organizers and all the participants for holding this important international conference, which is the first of its kind.
Bamboo is available everywhere around the world and is an abundant natural resource. It has been a conventional construction material since ancient times. As the development of modern material science progresses, a large amount of masonry, concrete and steel are used in the building structure, but bamboo and some other non-conventional natural materials still exist and are being used due to their natural characteristics and good mechanical properties. As a matter of fact, some regions in the world continue to use bamboo structures to this day.
Therefore, should we transform the conventional structure to modern structure member or system by means of the modern technologies, the bamboo structure will possess a certain position and developmental perspective in the modern building and bridge constructions Chairman of the conference and professor of Hunan University and University of Southern California, Dr.
Xiao Yan has done a lot of research work on modern bamboo structures. I congratulate him and his team for having successfully built two bamboo structural bridges. His research achievements have provided beneficial reference for this research area. Taking this opportunity, I would like to share a true story about the utilization of bamboo. In the fifties of the last century, the Architectural Design and Research Institute of Guangdong Province where I work built a five story office building making use of bamboo.
The building was initially designed with a brick wall and pre-cast reinforced concrete slabs. However, at the time, our government called for saving steel as much as possible, so we used bamboo bars instead of steel bars in the pre-cast slabs. The bamboo bars were made of so-called moso bamboo strips with simple anti- corrosion treatments. After more than fifty years of usage, all the building slabs are still intact and function well, and I and my colleagues are working there everyday. Of course, it does not mean that these slabs are modern bamboo structures, but it has proved that bamboo can be the replacement of steel and also has a good durability.
At this conference, experts and researchers will gather to exchange the research information and discuss on many of technical aspects, such as the composition and characteristics of bamboo, test and analysis of bamboo members and structures, modern bamboo buildings and bridges, industrialization of bamboo products and so on. I believe it would contribute greatly to further research and development of modern bamboo structures. I regret that I have to go to Beijing this afternoon for the annual meeting of the Chinese Academy of Engineering, so I cannot attend the entire conference.
However, I look forward to learning more research findings from the proceedings of this conference. Congratulations to the success of the conference in advance! In order to use bamboo on a large scale as an engineering material, economically feasible, with a possible industrialization, it becomes necessary to study scientifically the plantation, harvesting, curing and treatment processes. After this initial stage, a complete statistical and probabilistic analysis of the physical, mechanical and micro-structural properties of whole bamboo culms of different species should be carried out.
Since , the research programs at PUC-Rio, supervised by the author, were mainly concerned with establishing the engineering properties of some of the existing bamboo in Brazil and creating new structural elements using bamboo for civil and rural construction. The present paper has as its main objective to present the physical and mechanical properties of whole bamboo culms in addition to determining the functionally graded composite properties using data processing imagine of the studied bamboo.
A concise report about the structural elements such as bamboo space structure and different structural concrete elements reinforced with bamboo in addition to the several successful constructions built in Rio and Sao Paulo is given. Industrialized materials, such as Ordinary Portland Cement OPC and steel, find application in all sectors and any part of the world to which a road leads.
In the last half of the 20th century advanced materials, constituents of synthetic polymers such as Rayon, Nylon, Polyester, Kevlar, new alloy metals and carbon fibers, among others, are being developed and are introduced in places where locally produced materials exist in abundance, especially in developing countries. In developing countries due to the educational system, which is mainly based on programs from industrialized nations, there is still no formal education or research program concerning the traditional and locally available materials and technologies.
Lack of reliable technical information about the local materials leads the inhabitants and specialists to use mainly industrialized materials for which the information is freely available Ghavami, , The construction industry is one of the most polluting on earth. On the one hand housing is still urgently needed as there are millions, alone in the developing world, without homes cities have grown beyond their limits, have sprawled in all directions, which not only create problems with transport, energy, different wastes and water-supply but as well have invaded eco-systems and valuable green space necessary for agricultural use.
Nature has suffered irreparable damage. The consequences become more and more evident: Crops fail; there is a lack of drinking water, lack of water in the reservoirs for energy generation etc. Armed conflicts around the world contribute even more to the human misery. At this point it does not lead anywhere blaming the 5 industrial countries because they cause more pollution in the nature of their activities. Waiting for them to clean up, thinking that they have the means to do so, does not resolve the problems either. Everywhere, actions need to be taken to try to reverse the present state.
Various other national and international events disseminated on-going research projects. Now steps need to be taken to implement the results of the research investigations which have been ignored for years for not being agreeable to centralized multinational industries Ghavami and Rodrigues , Ghavami and Zielinski The whole construction process has to be revised starting with the location and the choice of materials to the different production processes. The answers are there already but they are followed by only a few.
The few research centers make hardly a difference. These topics need to be taken up and supported by governmental agencies, NGOs, private enterprises industries and especially multi-national industries. Before starting to build new houses one should look at the existing already. It has been a trend recently, and this worldwide, to abandon the old city centre and build at the periphery of the city getting further away from the centre and its commercial activities Swamy, To overcome the serious housing problem in Brazil and in other developing countries around the world, the author of this paper has been carrying out several successful research program since using indigenously available local materials such as bamboo, vegetables fibers, soil, quick lime, and cement mortars in the production of new structural elements such as bamboo space structures, corrugated sheets made of cement mortar composites reinforced with sisal, curaua and coconut fibers, soil-fibers composite for load bearing walls and concrete elements reinforced with bamboo beside the study of traditional construction Ghavami and Hombeck , Ghavami and Culzoni , Ghavami and Villela , Moreira, The main problem with the ample application of the structural elements developed is still the lack of sufficient information concerning each constituent of the composite and its durability besides sufficient financial support.
The focus of this paper is to present a summary of information about the mechanical, physical at meso structure of bamboo and its application as a low cost energy saving material, which is locally available for producing the space structure concrete structural elements reinforced with bamboo.
Some successful examples of the application of the results in practice also reported. Up to the eighties of the last century its use was limited to the construction of some scaffolding and simple dwellings. In Brazil systematic studies were carried out on bamboo since , of which the greater part was dedicated to the development of a methodology for its application in space structures and as reinforcement in concrete.
The energy necessary to produce 1 m3 per unit of stress projected in practice for materials commonly used in civil construction has been compared with that of bamboo. It was found that for steel it is necessary to spend 50 times more energy than for bamboo Janssen, In the production of one tone steel two tons of CO2 is produced. In contrast bamboo plant absorbs CO2 besides producing oxygen.
The tensile strength of bamboo is relatively high and can reach MPa Dunkelberg, , Liese, , Lopes, , this turns the use of bamboo attractive as substitute of steel, especially when considering the relation between tensile resistance and specific weight of bamboo which is six times greater than that for steel Ashby, , Wgst, et al. The bamboo culm, in general, 6 is a cylindrical shell, divided by transversal diaphragms at the nodes.
Bamboo is an orthotropic material with high strength along and low strength transversal to its fibers. The structure of bamboo is a composite material, consisting of long and aligned cellulose fibers immersed in a ligneous matrix Liese, A close-up of a cross-section of a bamboo culm shows that the distribution of the fibers is variable along its thickness.
This presents a functionally graded material, produced according to the state of the stress distribution in its natural environment Amada, , As it can be seen in Fig. In establishing the mechanical properties of bamboo in the elastic range using the rule of mix for the composite materials, the properties of the fibers and matrix with their volumetric fractions should be taken into account. Equation 1 presents the calculation of the elasticity modulus, Ec, of the bamboo as a composite.
The assumed hypotheses in the development of equation 1, beside the long and aligned fibers, consider also the perfect bonding between fibres and matrix as well as the uniform spacing between fibres Ghavami and Rodrigues, Considering that the Vf x distribution follows an axis x, originating in the internal wall thickness with the maximum limit at the outer wall of the bamboo culm, equation 2 can be written. The variation of the fibers along the thickness, Vf x , was determined using the digital image processing, DIP.
For this purpose, three samples are taken from the bottom, middle and the top part of bamboo culm, as shown in Fig. Non-uniform fiber distribution on cross section of bamboo. Fiber distribution across the bamboo thickness using DIP method. The variation of fiber volume fraction across the thickness of bamboo, Vf x , at the three parts for DG, are given in Fig. It is observed that the fiber distribution is more uniform at the bottom than at the top and the middle parts. This phenomenon could be explained knowing that the bamboo is subjected to maximum bending stress due to wind load and its own weight in the base.
However, the differences between the distributions are not very significant.
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Therefore all the data presented in Fig. Physical property of whole bamboo culm-The variation of the wall thickness and internodal distance of entire bamboo culms of the species Dendrocalamus giganteus DG , Moso, Matake, Guadua and Phylostaques pubensen have been measured as shown in Fig. The internodal length is larger in the middle part and the thickness decreases from the bottom to the top of the bamboo culm.
Based on the obtained data a mathematical formula, which relates the thickness, t, to the position of the internode, n, is established for all species of bamboo studied. The relation for bamboo DG is given by equation 4. With the help of this equation the designer can choose the required thickness from the range of bamboo species. Variation of thickness and internodal length along the whole bamboo culm.
Tensile test set up. Similar mathematical formulas are developed for diameter and internodal length of the bamboo. These results allow establishing easily the mechanical behavior of different types of bamboo. The results of the tensile and compression tests are given in Table 1. Dimensions and position of the strain gauges in compression test. The prototype was simply supported at four points and load was applied vertically at the centre of the structure, node 9, through a hydraulic jack with a capacity of kN.
The load of 0. The strains in the individual elements were measured by means of electrical strain gauges and the displacements of the nodes with electrical transducers of linear displacements, LVDT. To verify the symmetrical behavior of the prototype, the reactions of the support were measured by load cells. The DLG prototype failed when the applied load at the centre of the structure was 32 kN.
The failure occurred due to shearing stress of This failure shear value was lower in relation to the failure stress of the isolated tested connections, with had a mean value of 21,63 kN. The failure of the bamboo in the connection is shown in shown in Fig. The capacity to absorb water was studied on several bamboo species.
The obtained results have shown that the Dendrocalamus giganteus, DG, and Bambusa vulgaris schard, BVS, absorbed the least water in comparison with other species Culzoni, To produce an effective impermeability treatment three factors were considered: The adhesion properties of the applied substance to bamboo and concrete, water repellent property of the chosen substance and the creation of rough surface on bamboo. The bonding between bamboo and concrete considering twenty five types of products was established on pull-out test specimens. To isolate the secondary effects due to non-uniform shearing stress distribution in conventional tests, only the mm middle part of the bar was subjected to bonding shear stress.
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The other two parts are prepared for zero shears Culzoni, , Ghavami and Culzoni, The maximum size of aggregates was 20 mm. A beam reinforced with steel bars was always considered as reference. The lightweight aggregates were expanded clay commonly used in southeast of Brazil and fabricated in Sao Paulo. In the Northeast of Brazil the laterite aggregates which exist in abundance were considered. Throughout the research programs only ordinary Portland cement CP and natural-washed river sand were used. The concrete mix proportions for normal concrete were 1: The compressive strength of the concrete was established on 15 cm diameter and 30 cm high cylinders.
The split bamboo culms were of 30 cm width rectangular sections. The smooth surface of the bamboo splints were cleaned and slightly roughened before a thin layer of the impermeable product was applied. Then the splints were allowed to dry before being fixed inside the form work.
The length of the beams was cm with free span of cm and their cross sections were 12 cm wide and 30 cm deep. The beams were fabricated by pouring the concrete into the form work in layers of 10 cm and then vibrating as recommended by the Brazilian Norms. All beams were cured for 28 days, using wet sawdust, before they were tested. The same methodology and concrete as for bamboo reinforced concrete beams were applied to establish the mechanical and structural behavior of the slab of which the largest had a cross section of 80 cm width by 14 cm height with an overall length of cm and a free span of cm as shown in Fig.
A half split DG bamboo culm which works as a tensile reinforcing bar and also as permanent shutter form was filled with concrete as can be seen in Fig. For this investigation normal, lightweight and laterite concrete as for beams were used. The experimental results have been analyzed using conventional analytical methods and proved not to be sufficient enough as this type of structural element works as composite slab with the bamboo diaphragms acting as connectors.
Therefore for the analysis of the slabs beside the normal semi-analytical method the layer-wise theory and Finite Element method were used to realize a parametric study considering different variables 12 a Permanent shutter bamboo working as tensile reinforcement b Permanent shutter bamboo with full diaphragm shear connector d Push-Out test C Permanent shutter bamboo slab before testing Figure 8. Concrete slabs reinforced with bamboo permanent shutter forms. One of the important factors which have a great influence on the ultimate load of the slab is the shearing resistance of the bamboo diaphragms which act as shear connectors.
The shearing resistance of whole and half bamboo diaphragms of specie DG have been studied. For the half bamboo its shearing strength has been found to be Although the bamboo diaphragm creates a composite interaction between bamboo and concrete, its shear resistance is not sufficiently enough to prevent its shearing failure of the connector. Most of the tested slabs had first failed due to bonding and failure of the diaphragm then followed by concrete compression failure.
To increase the shearing strength of half bamboo several alternatives have been considered. One of the simplest methods was to fix a strip of steel or bamboo rod close to the bamboo diaphragm passing through the bamboo diameter. This method almost doubled the shear strength of the diaphragm hence the ultimate load of the slabs. The full diaphragm as shown in Fig 8b also presented to be very effective. This type of slab is now used in Brazil. At present, studies are underway to improve the bonding between bamboo and concrete with new products such as Sika 32 in addition to the shearing behavior of the connectors see Fig.
The main reinforcement of this 30 cm diameter column is made entirely of treated 3 cm DG bamboo segments. In this series of test beside the bamboo reinforcement the concrete form is also entirely made of bamboo. Bamboo can be left to work as a permanent shutter which besides having a pleasing aesthetic appearance can economize the finishing costs of the concrete Ghavami and Villela, The second series were the concrete columns of 20 cm by 20 cm and 13 c Torsion and Flexo-torsin expermential set up a Cicular column Figure 9. The strips in this series made of 5 mm steel bars.
In both series one conventional concrete column reinforced with steel was tested. Electrical strain gauges were fixed to the reinforcing bars of the column in order to compare the test results with those of the calculated ones. The test results have shown that the maximum load of bamboo reinforced concrete is the same as the one reinforced with steel.
The bounding was in a very good conditions. The bamboo segments were taken out and their tensile strength were verified. Surprisingly most of the bamboos have shown higher strength as compared with those measured four years earlier. Recently the torsion and flexo-torsion behaviour of bamboo culm of the species Moso, Dendrocalamus Giganteus and Guadua Angustifolia have been studied in detail.
The experimental set up is shown in Fig. In stage 1 for a small load, the stress and strain are in linear elastic range. The normal compression and tension stresses in a section in concrete are triangular. With an increase of the applied load the internal stress diagram of concrete along the depth of the section becomes non-linear until the ultimate tensile strength of the concrete is reached. In stage 2 the bamboo at the cracked points and in the concrete between the crack, in the tension zone resists the internal tensile stresses.
The stress distribution in the bamboo in the un-cracked part is similar to the conventional pull out test i. With the increase of the applied load the stress diagram in the compression zone of concrete continues to be non linear before its ultimate strength and bamboo in tension starts to break from its lower layer and hence, starting the third stage. In stage 3 the diagram of normal compression zone of concrete is of parabolic shape. However for the development of formulas for the practical design a rectangular shape is adopted.
Depending on the percentage of bamboo reinforcement three cases may occur: Stress and strain distribution in an element subjected to bending at different stages. Based on the obtained experimental data of the beams and one way composite slabs and the explained failure modes formulas for the design of these reinforced concrete elements have been developed. In all the bamboo reinforced beam tests realized up to present the failure mostly occurred due to tensile failure of concrete and bamboo.
Although in several cases the test beams were over-reinforced but no compression failure was provoked. This is mainly due to imperfect bonding between bamboo and concrete. With the advent of new products a research program is underway to overcome this. However, in the permanent bamboo shutter slabs with only a diaphragm as connector the collapse was mainly due to shear failure of connector.
Its durability depends very much on the species, age, right conservation, treatment and curing which is initiated already when being cut in the bamboo grove. There is a strong relation between insect attacks, humidity content and starch of bamboo. In order to reduce the nutrition content, bamboo needs to pass through a curing process such as: Drying bamboo is fundamental for its conservation for various reasons. Physical and mechanical properties increase when bamboo has a low humidity content.
Bamboo to be treated needs to be dry to facilitate penetration and obtain a better result and reducing transport costs. Bamboo can be dried in air, green house, oven or by fire. The durability of bamboo depends strongly on the preservative treatment methods in accordance with basic requirements: The preservative can be applied using simple systems such as leave transpiration, immersion, impregnation, Modified Boucherie Method or sophisticated modern equipment of cauldrons and special chambers working with vacuum or pressure.
Many steel and concrete buildings constructed during the last 30 years reveal serious deterioration caused mainly by the corrosion of the steel reinforcement. Many on-going research programs are concerned about the rehabilitation of these conventional reinforced concrete structures for which millions of US dollars are spent. Durability of bamboo and steel concrete elements. The bamboo reinforced beam after testing has been exposed to open air in the PUC-Rio university campus.
It can be observed that the bamboo segments treated against insects as well as for bonding with IGOL-T show a very satisfactory behavior and appearance after 15 years. However, the steel reinforcing bars after ten years had a serious corrosion problems and are being substituted. The bamboo segments of the beam were taken out of the concrete and tested for their mechanical strength. They had a slight deterioration in their tensile strength as compared with the original untreated bamboo 2.
All the internal parts including the wall finishing, tables, chairs, hangers, lamp shades beside the roof tiles, are made of bamboo. The structural columns, walls, doors, windows, roof tiles and drains are made with treated Dendrocalamus Giganteus and also some part with bamboo Mosso, and Matake. In the village Camburi of the municipality of Ubatuba, where the inhabitants live in traditional Taipa houses, which are in a very bad conditions due to the lack of maintenance. The inhabitants have forgotten or are not willing to use this traditional sustainable way of construction and are waiting for the local authority to offer them cement, sands and aggregate for the construction of new houses.
As in other communities when the bamboo construction was suggested to the leaders of the village they categorically rejected. As the objective of the members of the Bamboostic NGO from Belgium and the author of this paper as the coordinator was to introduce bamboo and other non-conventional materials and technologies in less developed regions special strategy had to be chosen. First in order to gain the confidence of the local community which did not know bamboo nor believed that it could be used in any engineering project, the recently graduated young Belgians, Figure Construction of kiosk using bamboo and earth.
Digital project of sustainable community center of Camburi. After the completion of the bridge the inhabitant of the village could be convinced that bamboo was a good construction material and started to show interest to learn about the techniques in the use of bamboo. At the second stage in collaboration with the local inhabitants Camburi cooperative was organized.
It was planned to create a source of income, through tourism and sell the handicraft produced locally. For this a modern kiosk was projected to be constructed with bamboo in the main square of the village. The cable stayed bamboo Kiosk shown in Fig. To extend the training of the bamboo builder, a small information center was also at the entrance of the Camburi which is about three km away from the center of the village.
In the construction of the building the principal of Taipa construction using bamboo and local clay has been used. The structure is covered with a locally available straw. With these two last constructions the new builders were trained satisfactorily, so that a community center of m2 as shown in Fig. In this project it was planned to use the principles of sustainability, as far as possible, by using bamboo, stones, soil, quick lime, green roof and other non-conventional materials and techniques. The construction projects were carried out in cooperation with Bamboostic which gave a financial support also and the ABMTENC Brazilian association into non-conventional Materials and technologies.
The total dedication, perseverance and the involvement in the organization of the Camburi cooperative by the architect Sven, Hilde and Pieter were the most important for the the active and effective participation of the community members of Camburi in the execution of this project. Now the local bamboo builders acting enthusiastically and giving suggestions, in order to improve the practical application of the obtained results in the research laboratory Figs.
As can be seen in Fig. Community centre of Camburi in the municipality of Ubatuba, SP. Nano and ecological architecture, for country towns. With ecology and sustainability in mind, various architectural projects have been developed at PUC-Rio and also in collaboration with other universities in Brazil and abroad. The principle of the development of this project is based on nano architecture. The term nano architecture is referred here to the study of nano structure of bamboo which would allow the researcher to treat bamboo with some compatible nano particle or a compatible natural or synthetic polymer with the objective to make bamboo equal or superior to many conventional construction materials made of steel, PVC, aluminum etc.
The initial architectural project shown in Fig. In this way it is hoped to slow down the emigration of rural workers from small country towns to big cities creating still the existing problems worse. First attention was given to the issue of limited resources, especially energy, and how to reduce the impact on the natural environment. Now emphasis is placed on more technical issues such as sustainable materials, building components, construction technologies and energy related design concepts as well on non-technical issue such as economic and social sustainability.
Since research has been carried out in Brazil on non-conventional materials and technologies. New building components were developed using vegetable fiber as reinforcement of cement mortar and bamboo as permanent shutter forms in concrete slabs and columns. Our concern was as well the dissemination of our work which occurred through publications and special courses.
The Brazilian Association of the sciences of non-conventional material technologies abmtenc , was founded to further the dissemination and the cooperation between engineers, architects, designers and civil servants related to housing. Based on the research results of bamboo obtained in Brazilian universities and other institutes around the world with the leadership of INBAR the first norms for bamboo were created determining the physical and mechanical properties of bamboo.
Norms are important not only for dissemination but also for the safe usage of a material. The use of bamboo reinforced concrete elements provide an exciting challenge to the housing construction industry, particularly in developing countries, since they are a cheap and readily available form of reinforcement, require only a low degree of industrialization for their processing and, in comparison with an equivalent weight of the most common steel reinforcement, the energy required for their production is small and hence the cost of fabricating these structural elements is also low.
In addition, the use of bamboo requires low degree of transportation and only a small number of trained personnel in the construction industry. Development and application of bamboo structural elements thus pose the challenge and the solution for combining non-conventional building materials with conventional construction methods. Thesis, Eindhoven University of Technology, Holland. Bamboo is one of the oldest and most versatile building materials with many applications in the field of construction, particularly in developing countries.
It is strong and lightweight and can often be used without processing or finishing. Bamboo constructions are easy to build, resilient to wind and even earthquake forces, and readily repairable in the event of damage. Associated products such as bamboo based panels and bamboo reinforced concrete also find applications in the construction process. In spite of these clear advantages, the use of bamboo has been largely restricted to temporary structures and lower grade buildings due to limited natural durability, difficulties in jointing, a lack of structural design data and exclusion from building codes.
The diminishing wood resource and restrictions imposed on felling in natural forests, particularly in the tropics, have focused world attention on the need to identify a substitute material which should be renewable, environmentally friendly and widely available. In view of its rapid growth, a ready adaptability to most climatic and edaphic conditions and properties superior to most juvenile fast growing wood, bamboo emerges as a very suitable alternative.
However, in order to exploit fully the potential of bamboo as a construction material, development effort should be directed at the key areas of preservation, jointing, structural design and codification. It is widely used for many forms of construction, in particular for housing in rural areas. Bamboo is a renewable and versatile resource, characterized by high strength and low weight, and is easily worked using simple tools. As such, bamboo constructions are easy to build, resilient to wind and even earthquake forces given the correct detailing and readily repairable in the event of damage.
Associated products bamboo based panels and bamboo reinforced concrete, for example also find applications in the construction process. There are however a number of important considerations which currently limit the use of bamboo as a universally applicable construction material: For this reason, untreated bamboo structures are viewed as temporary with an expected life of no more than five years. Considerable research has been directed at the development of more effective jointing methods. The majority of bamboo construction relates to rural community needs in developing countries.
As such, domestic housing predominates and, in accordance with their rural origins, these 23 buildings are often simple in design and construction relying on a living tradition of local skills and methods. Other common types of construction include farm and school buildings and bridges. Further applications of bamboo relevant to construction include its use as scaffolding, water piping, and as shuttering and reinforcement for concrete.
In addition, the potential number of construction applications has been increased by the recent development of a variety of bamboo based panels. It is, however, often used in conjunction with other materials. Bamboo building construction is characterized by a structural frame approach similar to that applied in timber frame construction. In this case, the floor, wall and roof elements are interconnected and often one dependent on the other for overall stability.
There is a need to control lateral deformations in some traditional forms of building in particular. The adequacy and suitability of the building for occupancy will also depend to a large extent on good detailing, for example to help prevent water and moisture ingress, fungal attack and vermin infestation. All of the above features are dealt with in the following sections. However, the preferred solution is to raise the floor above the ground creating a stilt type of construction. This improves comfort and hygiene and can provide a covered storage area below the floor.
When the floor is elevated, it becomes an integral part of the structural framework of the building. The beams therefore run around the perimeter of the building. Where the beams are fixed to posts, careful attention to jointing is required. Beams and columns are generally around mm in diameter. Bamboo joists then span in the shortest direction across the perimeter beams.
The joists are often laid on the beams without fixing, but some form of mechanical connection is recommended. Depending on the form of floor decking, secondary joists, often taking the form of split culms may 24 Slab level b a Figure 1. Examples of columns set a in concrete footing and b on steel shoe.
Joist diameters are in the order of 70 mm. Joist centres are typically to mm, or up to mm if secondary joists are used. The major elements of a bamboo wall generally constitute part of the structural framework. As such they are required to carry the building self-weight and loadings imposed by the occupants, the weather and earthquakes. An infill between framing members is required to complete the wall. The purpose of the infill is to protect against rain, wind and animals, to offer privacy and to provide in-plane bracing to ensure the overall stability of the structure when subjected to horizontal forces.
The infill should also be designed to allow for light and ventilation. Not least is its architectural and aesthetic function. This infill can take many forms: Wall construction using plastered bamboo grid. Above all, it must be strong enough to resist the considerable forces generated by wind and roof coverings.
In this respect bamboo is ideal as a roofing material—it is strong, resilient and light-weight. Bamboo, in a variety of forms, is also used as a roof covering and for ceilings. More often, they are non-structural in function.
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It is light, strong and resilient, waterproof and impermeable with low thermal conductivity and good fire resistance. Bamboo doors can be side hinged or sliding, comprising a bamboo frame with an infill of woven bamboo or small diameter culms. Bamboo windows are generally left unglazed and can have bamboo bars, or a sash with woven bamboo infill. The sash can be side hinged or sliding, or, more commonly, top hinged to keep out direct sunlight and rain. At night, windows are closed to protect against insects and animals. Hinges are formed from simple bindings, or connecting bamboo elements.
It provides a ready food source for insects and fungi, and can decay in less than a year in direct ground contact. Protection is therefore essential to ensure the longest possible life for the material, and the building in which it is used. Protection does not necessarily mean chemical treatment. The first line of defence postharvesting is good design. The risk of more general flooding can be reduced by building on a graded or slightly sloping site, and using raised masonry or concrete footings.
The effects of water inside the building should not be overlooked. Simple provision can be made to drain away washing and cooking water, avoiding the hazards of prolonged wetting see Fig. Raising bamboo columns or wall panels clear of the ground also reduces the risk of termite infestation, and improves visibility, making inspection easier. Termite shields can be used between the footings and walls, if the risk is considered high. Where possible, the roof space should be left exposed to improve both visibility and airflow, and aid routine maintenance.
Bamboo constructions can also provide ideal nesting areas for rodents and other pests. In general, open culm ends should be plugged and cavity construction should be avoided. Tank containing preservative, located at high level 2. Flexible rubber tubing Figure 4. Arrangement for Boucherie treatment process. However, chemicals over which there are environmental and health and safety concerns should be discounted. Tar oil and boron based chemicals are relatively safe options, and are often available locally. Four treatment methods are ideally suited to site or workshop application: In general terms, therefore, the range of types, spans and capacities is almost infinite.
Bamboo bridges, however, are generally of trestle construction and of limited span for carrying only light usually pedestrian traffic. Simple trussed constructions have also been built and have been shown capable of supporting substantial loads. The main advantages of bamboo scaffolding when compared with steel are its lightness and low cost. It is also readily tailored to suit the shape of a building. However, problems such as lack of durability, and non-standardised jointing currently limit its wider application. There are several good reasons why bamboo might be considered as reinforcement for concrete: To date, many different panel types have been developed, mostly in Asia, but investigations into construction applications have only recently been carried out Ganapathy et al.
Bamboo based panels have proved suitable for structural as well as non-structural applications, in both low and high grade building work. Specific end uses include floors, walls, partitions, doors, ceilings and roofs, and by virtue of their inherent rigidity and enhanced durability through preservative treatment , such panels can offer significant advantages over the use of bamboo in its natural state. The various types of panel product can be broadly classified as follows: Furthermore, the suitability of a material for use in framing is largely dependent upon the ease with which joints can be formed.
Because of its round, tubular form, jointing of two or more bamboo members requires a different approach to that adopted for, say, solid timber. Despite its relatively high strength, bamboo is susceptible to crushing, particularly of open ends. It is also characterised by a tendency to split; the use of nails, pegs, notches or mortises can therefore result in considerable reductions in strength. Connections must also cope with variations in diameter, wall thickness and straightness. However, the building of structurally efficient, more durable and possibly larger and more economical bamboo structures will depend to a large extent on improvements and developments in jointing technology.
The basic joint types are: It is therefore good practice to make joints as close to nodes as possible. For example, in the simple saddle joint, the saddle should be formed directly above a node. If a hole is made in a culm for a peg, dowel, mortise, inset support or insert this should be as close as possible to the node, paying particular attention to the direction of the applied force. Furthermore, whenever possible holes should be round or radiused rather than square cut as these are less likely to propagate splits.
Firstly, bamboo shrinks on drying and this will generally cause joints to loosen. Secondly, drying splits can form which could further weaken the assembly Narayanamurty et al. In trusses, the use of quarter-round bamboo bearing plates reduces the risk of crushing of the chords by the compression webs Janssen, The use of wire is in many cases preferable to bamboo lashings or rope as it is not subject to insect attack. However, their adoption and suitability will depend to a large extent on the cost and availability of materials, equipment and skilled labour.
In the case of bamboo, information from this source is somewhat limited. Considerable effort continues to be directed at the derivation of mechanical properties, but perhaps with insufficient regard to applications in the field. Janssen , however, has shown that a relationship exists between density and permissible stress which forms the basis of Table 1 below: Air dry Green Axial compression no buckling Bending Shear 0. Other studies relate to specific species, or groups of species. Bending Stiffness Compression Fundamentals of the design of bamboo structures. Doctoral thesis, Eindhoven University of Technology, Netherlands.
Bamboo based panels—a review unpublished. Technologies developed in Columbia in the bamboo housing and construction field. Building with bamboo, a handbook. Bamboo in construction, an introduction. The use of bamboo and reeds in building construction. Classification, grading and processing of bamboos for structural and other applications.
Bangalore , India. There has been a serious concern to look for alternative housing materials that are cheap, widely available and environmentally friendly. Bamboo is one of the best materials that have been used for centuries as a building material due to its versatile characteristics. Bamboo housing is not a new concept. It is estimated that more than a billion people live in bamboo houses mostly in developing worlds. The ecological and economical dynamics of bamboo have made it a sustainable building material.
Various testing, researches and practical experiences have revealed that bamboo has high tensile strength, high strength to weight ration and high specific load bearing capacity. Due to its long, strong and elastic nature of fibbers; bamboo is known as high resistance to the earth quake. It has also natural insulation properties that would save thermal energy and it is a very durable material if treated properly. This paper mainly deals with the prospects, constraints and opportunities to use bamboo as building material in the 21st century.
There are about 75 genera and species worldwide Sharma, , with total bamboo areas about 22 million hectares and with a yield of million tons Zehui, It grows from tropical to sub-temperate regions, though the great diversity is found in subtropical region. It is known to be one of the fastest growing plants in the world. Its growth rate ranges from 30 cm to cm per day.
Bamboo grows densely sometime more than 10, culms per hectare and can be easily regenerated naturally. Bamboo attains its maximum size in 60—90 days of shoot sprouting and can be harvested in 3 to 6 years depending upon species. Bamboo multiplying is very easy as it expands naturally with rhizome. Its natural expansion capacity and short rotation have made it well known as an environmentally green plant.
Bamboo has a very long history for its use in various purposes such as food, shelter, furniture etc. Bamboo has been serving humanity from cradle to grave in many countries since ages in many different and ingenious ways. It has strength, flexibility and versatility and therefore is suitable material for the various types of construction.
Its strength, flexibility and versatility make it a suitable material for addressing every housing component when treated and used properly. Bamboo is relatively cheap, easy to work with and readily available in most warm climate countries. Bamboo can be a potential building material in the most of the developing countries where it grows. Fortunately, it grows in the most of the African and Asian countries where the affordable 33 Table 1. Comparison of important strength properties of bamboos and wood of India. There are 65 species of bamboo which are used in construction purpose Jayanetti and Follet, Gauda augustifolia is the mst popular species in Latin America countries.
Similarly, Bambusa nutans, Dendrocalamus strictus, Dendrocalamus hamiltonii Bambusa balcooa, Bambusa vulagris, Phyllostachys bambusoides are widely used in Asian countries.
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Bambusa arundinaceae and Bambusa vulgaries are found to be very suitable species for construction in Africa Oteng, In certain mechanical properties, bamboo even surpasses timber and concrete. However, it is difficult to generalize the properties of bamboo as it differs with the species, age, climatic factors, moisture content and different heights of the culm.
Bamboo possesses excellent strength properties especially tensile strength. Study shows that bamboo is as strong as wood and some species even exceed the strength of Shorea robusta and Tectona grandis Sattar, , table 1. An increase in strength is reported to occur at 3—4 years and thereafter it decreases. Therefore maturity period of bamboo is considered 3—4 years with respect to density and strength. The comparison clearly reveals that bamboo is better in properties than that of Spruce and equal or more than steel in tensile strength.
More importantly the failure in bending of bamboo is not actually totally failure. Due to its strong fibers, it first cracks unlike timber which breaks if bending fails Janssen, This quality of bamboo gives an opportunity to repair or replace failure parts of house. The elasticity of bamboo is better than wood for seismic resistant housing and as has been proved in the case of several small houses. One more advantage of bamboo over timber is that it does not have rays. Rays are mechanically weak therefore bamboo material is better in shear than timber material.
They can be used as it is without any major processing or can be processed into panels. Based on the ways bamboo used for the construction, bamboo building technologies can be divided broadly into two types 1 bamboo building using round unprocessed bamboo culms and 2 bamboo building using engineered processed bamboo. This technology emerged from the beginning when people started to use bamboo as a building material and has been improved significantly in accordance with modern housing technology. The technology can be further classified into various construction systems as follows; Bahareque System: Bahreque is a traditional bamboo building wall system in Latin American countries mainly in Ecuador and Columbia.
There are two types; hollow and solid. In solid type, horizontal bamboo laths are fixed on both sides of culms or timber frame and the space is filled with mud. In hollow type, estrilla flattened bamboo is fixed both sides of culm and is plastered with mud or cement mortar Paudel and Lobovikov, Quincha is also a Latin American System. There are two types of quincha. The first one is Quincha with wooden frame which is a slight modification of traditional Bahareque. The main structure of the wall is a wooden frame.
Each side of the frame is covered with horizontally placed bamboo esterilla with the green side facing inwards. In some cases bamboo laths are used the fix the flattened bamboo to the wall panel. The wall is then plastered with cement mortar. The second system is Quincha with bamboo frame in which wall is fabricated with bamboo poles and flattened bamboo with the green side facing inwards.
The exterior of the wall was plastered with mud and cow dung. The interior of the wall was left for the bamboo view. The columns are tied at the top with wooden plates and bottom is embedded in foundation concrete. The wall is made up of grid of bamboo lath and chickens mesh and plastered with cement mortar and bamboo lath and steel dowels hold spaces between columns. Roof consists of bamboo trusses, bamboo purlins and bamboo corrugated mats. A typical Hogar de Cristo wall includes a wooden frame with flattened bamboo on one side of the frame.
However, the system has been modified and improved with double bamboo wall in wooden frame plastered with mortar both sides of the wall. This modified system has been used in Nepal to build low cost residential houses and community buildings. This system gives more stability and durability to the house. This system is developed by Bamboo Technologies, a Hawaii based company that pre-fabricates bamboo houses in Vietnam and shipped them to the final destinations. In this system, bamboos are used for poles, trusses, beams and wall panels.
The wall is made of flattened bamboos that sandwich plywood. Bamboo view can be seen in both sides of the wall. Hollow and Solid Bahareque walls Courtesy: Quincha walls with bamboo poles Courtesy: Grid wall system Courtesy: Pre-fabricated bamboo house in Nepal Courtesy: INBAR has recently researched and built various kinds of pre-fabricated modular bamboo houses and established them in its demonstration site in Beijing. A modern bamboo house by Bamboo Technologies. In certain conditions, using unprocessed bamboo could be beneficial and useful.
In other situation, using processed bamboo may give better comparative advantages. The advantages and disadvantages of the technologies have been summarized in the table. The advantages, disadvantages and limitations of using processed and unprocessed bamboo for housing. It has a lot of economical and ecological strengths.
However, it has also several limitations and weaknesses that have been summarized in the table below. SWOTs of bamboo housing. Bamboo can replace wood for housing that would save thousands of hectares of forests. Based on species, age and locality it has different length of internodes, culms thickness, tapering ratio and size of hollowness.
It makes difficulties to standardize the material unless it is processed into panels. Bamboo housing and related industries can provide direct employment opportunities to the local communities through cultivation, management, pre-preprocessing and processing stages. In India only, bamboo generates jobs for a total of 60—72 million workdays before primary processing and million workdays for weaving works Janssen, They differ greatly in their physical and mechanical properties.
It makes difficult to control the quality of the bamboo as a building material. Knowledge of treatment has still not reached to the needy communities. Panel and beam can be standardized for their dimensions and properties and can be pre-fabricated and commercialized at industrial scale. It has a market potentiality both for low and high income classes. It can be grown easily and harvested in very short rotation to supply required quantity of bamboo culms.
Due to lightweight and favorable elastic property, its quality to resist earthquake pressure is very good. It has an image of poverty associated with it. People in many countries believe that bamboo is not a durable material and living in a bamboo house is just a temporary solution. However, there are still a few constraints and limitations that inhibit the promotion of bamboo as a building material at large.
However, such perception could be altered with proper extension education such as training, workshop, demonstration of high end buildings. The other problem of using bamboo lies within its own physical characteristics. Bamboo is a non dimensional material and is very difficult to use compared to other building material. However, technologies are being emerged to process bamboo into panels and beams that could be standardized for its dimensions as well as mechanical strengths.
INBAR has recently developed a pre-fabricated modular bamboo housing system using engineered bamboo panels and beams. The engineered bamboo has a great potential to be used as a building material in the future to solve the problems associated with unsustainable building materials.
Seismic testing of a bamboo based building system. Journal of Bamboo and Rattan, No. Discover, June , pp. Traditional Housing in Asia: World Publications, Singapore, pp. Bamboo construction Technology for housing in Bangladesh: