Contents

1 ContentsPrefacevii1. Introduction2. Protection of bamboo 3 Natural durability 3 Protection of plantations 4 Protection pre- and post-harvesting by non-chemical methods 4 Protection pre- and post-harvesting by chemical methods 63. Preservation of bambooNon-chemical (traditional) methods of preservationChemical treatment methodsDrying of bambooDevelopmental needs4.

2 Health, safety and environmental aspects ofpreservative treatment5. Construction methodsDomestic housing and small buildingsFoundationsFloorsWallsRoofsDoor s and windowsWater pipes and guttersDetailing for durability6. Other types of constructionBridgesScaffolding7. Other applications relevant to constructionBamboo reinforced concreteBamboo based panels1991018192123232428323643454751515 55757608. Jointing techniquesTraditional jointsimproved traditional jointsRecent developments9. Design considerations10. Toolst-land toolsProduction machinery11. Bamboo species suitable for construction12. Useful contact addressesReferencesAppendix 1 Practical guidelines for the preservative treatment of bambooAppendix 2 List of possible preservatives for treatment of bambooAppendix 3 Preservatives, retention, suggested concentrations of treatment solutionsand methods of treatment of bamboo for structural purposesAppendix 4 Preservatives, retention.

3 Suggested concentrations of treatment solutionsand methods of treatment of bamboo for non-structural purposesAppendix 5 Standard methods for determining penetration of preservativesAppendix 6 Tabular database of some bamboos used in construction6363727277797982838589971011 03105107111ivAcknowledgementsThe authors have referred to many important textswhile compiling this book and original sources areacknowledged authors are particularly grateful to the InternationalNetwork for Bamboo and Rattan (INBAR) for thetechnical assistance provided during preparation andediting. Appendices 1 to 5 have been reproduced fromthe publication INBAR Technical Report No. 3 bySatish Kumar, K.

4 S. Shukla, lndra Dev and P. , with the kind permission of the Indian Councilof Forestry Research and Education (ICFRE), INBARand the International Development Research Centre(IDRC).Special thanks are extended to Mr M. W. Parkes, theformer DFID Senior Architectural and Planning Adviser,and Mr M. Mutter, the present Adviser, without whosesupport and guidance this book could not have is one of the oldest and most versatile buildingmaterials with many applications in the field ofconstruction, particularly in developing countries, It isstrong and lightweight and can often be used withoutprocessing or finishing. In spite of these clear advan-tages, the use of bamboo has been largely restricted totemporary structures and lower grade buildings due tolimited natural durability, difficulties in jointing, a lack ofstructural design data and exclusion from diminishing wood resource and restrictionsimposed on felling in natural forests, particularly in thetropics, have focused world attention on the need toidentify a substitute material which should be renew-able, environmentally friendly and widely available.

5 Inview of its rapid growth (exceeding most fast growingwoods), a ready adaptability to most climatic andedaphic conditions and properties superior to mostjuvenile fast growing wood, bamboo emerges as a verysuitable alternative. However, in order to fully exploitthe potential of bamboo, development effort should bedirected at the key areas of preservation, jointing,structural design and codification. In addition, socio-economic, appropriateness and technical studies willbe essential to identify factors which govern currentbamboo usage, and those which will influence its usein the future. Once these issues have beenaddressed, bamboo will be ideally placed to becomea principal engineering and construction material forthe twenty first century and IntroductionBamboo has a long and well established tradition as abuilding material throughout the world s tropical andsub-tropical regions.

6 It is widely used for many forms ofconstruction, in particular for housing in rural is a renewable and versatile resource,characterised by high strength and low weight, and iseasily worked using simple tools. As such, bambooconstructions are easy to build, resilient to wind andeven earthquake forces (given the correct detailing)and readily repairable in the event of damage. Associ-ated products (bamboo based panels and bambooreinforced concrete, for example) also find applicationsin the construction are however a number of important considera-tions which currently limit the use of bamboo as auniversally applicable construction material: Durability: bamboo is subject to attack by fungi andinsects.

7 For this reason, untreated bamboo struc-tures are viewed as temporary with an expected lifeof no more than five years Jointing: although many traditional joint types exist,their structural efficiency is low (Herbert et al. 1979).Considerable research has been directed at thedevelopment of more effective jointing methods. Flammability: bamboo structures do not behavewell in fires, and the cost of treatment, where avail-able, is relatively high. Lack of design guidance and codification: theengineering design of bamboo structures has notyet been fully aim of this publication is to offer a general intro-duction to bamboo as a construction material, with thekey areas of preservation and jointing addressed inmore range of chemical and non-chemical treatmentmethods is discussed and appropriate preservativeformulations and treatment schedules are is given to environmental and health andsafety issues, and areas requiring further research section on jointing attempts to summarise andillustrate the many different joint types and connectionmethods that have been devised, from traditionaltechniques to recent developments.

8 It is hoped that thisaccumulated knowledge will inspire further work inthis Protection of bambooNatural durability As with all timbers, the service life of bamboo isgoverned by its exposure position and durability, whichtogether dictate the rate of attack by biological general it has been found that untreated bamboohas an average life of l-3 years where it is directlyexposed to soil and atmosphere. When used undercover, the life expectancy of bamboo increases to 4-7years. Under very favourable circumstances, theservice life of bamboo can be as high as 10-I 5 years,for example when used for rafters and internal chemical constituents of bamboo are known tovary greatly depending on species, position within theculm and the age of the culm.

9 In very general termsbamboo consists of 50-70% hemicellulose, 30%pentosans, and 20-25% lignin (Tamolang et al. 1980,Chen et al. 1985). 90% of the hemicellulose is xylanwith a structure intermediate between hardwood andsoftwood xylans (Higuchi, 1980). The structure of thelignin present in bamboo is unique, and undergoeschanges during the elongation and ageing of the culm(Itoh et al. 1981). Bamboo is known to be rich in silica( ), but almost the entire silica content is locatedin the epidermis layers, with hardly any silica in the restof the wall. Bamboo also has minor amounts of resins,waxes and tannins. However, none of these havesufficient toxicity to impart much natural durability to theculms.

10 Laboratory tests have indicated that bamboo ismore prone to both soft rot and white rot attack than tobrown rot (Liese, 1959).The natural durability of bamboo varies according tospecies. For example, Dendrocalamus strictus i sknown to be less resistant to termites than Dendroca-Iamus longispathus. Although the culms of a fewbamboos, notably Guadua angustifolia, appear to havea relatively high resistance to wood eating insects anddecay fungi, they are all susceptible to in durability has also been observed alongthe length of the culm and through the thickness of thewall. The lower portion of the culm is considered more3durable, while the inner part of the wall deterioratesfaster than the outer harder portion.