spore: profile id: bamboo spore_version: 0.2 family: bamboo name: Bamboo culm (structural bamboo) role: Structural stem for building, and fibre for fibre-reinforced composites category: living type: bio-grown-building-materials summary: | Bamboo culm is the stem of a bamboo grass. Measured Petung bamboo (Dendrocalamus asper) culms had tensile strength of 193 to 340 MPa along the fibre and a tensile modulus of 18,140 to 28,230 MPa, varying with culm diameter and wall thickness (Javadian et al. 2019). Moisture content moves with humidity, from 8.4 to 11.2% at 20 °C and 65% relative humidity, so each culm needs checking before use. best_for: Local building where the stem is grown nearby, and fibre composites that use the stem's fibre weakest_at: Strength and stiffness vary with position in the culm and with moisture; rapid moisture change can cause shrinkage, swelling and layer-bond failure (Javadian et al. 2019) identity: formula: Natural composite of cellulose fibres in a lignin and parenchyma matrix (culm wall of Dendrocalamus asper); no single chemical formula source: javadian2019 where: Introduction, microstructure paragraph (cellulose fibres reinforce the lignin matrix) tags: applications: - structures properties: - benchmark: density label: Specific density (oven-dry), range across culm subsections value: 0.711 value_high: 0.94 bound: range unit: (specific gravity, no unit printed) scope: material conditions: species: Dendrocalamus asper (bamboo Petung), Java basis: oven-dry weight divided by the weight of an equal volume of water (the paper's definition); dimensionless, no unit printed test: ASTM D2395-14 as cited by the paper moisture: oven-dry method: Measured by the authors on samples from the middle and bottom 1 m subsections of 15 culms, by the standard cited in the paper status: ground note: The lowest value (0.711) is class 7 at 19 to 20 mm wall; the highest (0.940) is class 4 at 6 to 7 mm wall. source: javadian2019 where: Table 3 (oven-dry SD by culm diameter and wall thickness) - benchmark: density label: Mean specific density, bamboo Petung (Green et al. 1999, as printed) value: 0.72 value_high: 0.91 bound: range unit: (specific gravity, no unit printed) scope: material conditions: species: Bamboo Petung (Dendrocalamus asper) basis: mean specific density compiled from Green et al. (1999) and printed in Table 8; no moisture basis stated method: Compiled mean printed in Table 8 of the paper; not measured by the authors status: ground source: javadian2019 where: Table 8, row Bamboo Petung, mean specific density - benchmark: ultimate_tensile_strength label: Tensile strength along the fibre, range across culm classes value: 193 value_high: 340 bound: range unit: MPa scope: material conditions: species: Dendrocalamus asper (bamboo Petung) form: small clear specimens cut from culm walls, tested along the fibre test: ASTM D143-09 small clear specimens moisture: not stated per row; culms as received had 12 to 15% moisture method: Tensile tests by the authors per ASTM D143-09, one value per culm diameter and wall-thickness class as printed status: ground note: The lowest value is class 7 at 19 to 20 mm wall; the highest is class 5 at 8 to 9 mm wall. source: javadian2019 where: Table 4 (tensile strength by culm diameter and wall thickness) - benchmark: ultimate_tensile_strength label: Mean tensile strength along the fibre, bamboo Petung (Green et al. 1999, as printed) value: 216 value_high: 323 bound: range unit: MPa scope: material conditions: species: Bamboo Petung (Dendrocalamus asper) basis: mean tensile strength along the fibre compiled from Green et al. (1999) and printed in Table 8 method: Compiled mean printed in Table 8 of the paper; not measured by the authors status: ground source: javadian2019 where: Table 8, row Bamboo Petung, mean tensile strength along the fiber - benchmark: elastic_modulus label: Modulus of elasticity in tension, range across culm classes value: 18140 value_high: 28230 bound: range unit: MPa scope: material conditions: species: Dendrocalamus asper (bamboo Petung) mode: tension, along the fibre test: ASTM D143-14 as cited by the paper method: Tension tests by the authors per ASTM D143-14, one value per culm class as printed status: ground note: The lowest value is class 7 at 19 to 20 mm wall; the highest is class 4 at 9 to 10 mm wall. source: javadian2019 where: Table 5 (modulus of elasticity in tension by culm diameter and wall thickness) - benchmark: elastic_modulus label: Mean modulus of elasticity, bamboo Petung (Green et al. 1999, as printed) value: 19600 value_high: 26110 bound: range unit: MPa scope: material conditions: species: Bamboo Petung (Dendrocalamus asper) basis: mean modulus of elasticity compiled from Green et al. (1999) and printed in Table 8; mode not stated in the table method: Compiled mean printed in Table 8 of the paper; not measured by the authors status: ground source: javadian2019 where: Table 8, row Bamboo Petung, mean modulus of elasticity - benchmark: flexural_strength label: Modulus of rupture, range across culm classes value: 121 value_high: 209 bound: range unit: MPa scope: material conditions: species: Dendrocalamus asper (bamboo Petung) test: two-point flexure, ASTM D3043-00(2011) as cited by the paper form: culm samples from 1 m subsections method: Two-point flexure tests by the authors per ASTM D3043-00(2011), one value per culm class as printed status: ground note: The highest value is class 1 at 6 to 7 mm wall; the lowest is class 7 at 19 to 20 mm wall. source: javadian2019 where: Table 6 (MOR by culm diameter and wall thickness) - benchmark: flexural_strength label: Mean modulus of rupture, bamboo Petung (Green et al. 1999, as printed) value: 130 value_high: 205 bound: range unit: MPa scope: material conditions: species: Bamboo Petung (Dendrocalamus asper) basis: mean modulus of rupture compiled from Green et al. (1999) and printed in Table 8 method: Compiled mean printed in Table 8 of the paper; not measured by the authors status: ground source: javadian2019 where: Table 8, row Bamboo Petung, mean modulus of rupture (MPa) - benchmark: flexural_modulus label: Modulus of elasticity in flexure, range across culm classes value: 9375 value_high: 14279 bound: range unit: MPa scope: material conditions: species: Dendrocalamus asper (bamboo Petung) test: two-point flexure with mid-span deflection from an extensometer, ASTM D3043-00(2011), room temperature and 65% relative humidity method: Measured by the authors from the flexure load-deflection curve per ASTM D3043-00(2011) status: ground note: The highest value is class 2 at 9 to 10 mm wall; the lowest is class 7 at 19 to 20 mm wall. source: javadian2019 where: Table 7 (modulus of elasticity in flexure by culm diameter and wall thickness) - benchmark: moisture_content label: Moisture content at 20 °C and 65% relative humidity, range across classes value: 8.4 value_high: 11.2 bound: range unit: '%' scope: material conditions: species: Dendrocalamus asper (bamboo Petung) condition: 20 °C and 65% relative humidity standard: ASTM D4442-07 cited by the paper for moisture content determination method: Measured by the authors on 1 m subsection samples at the stated condition; one value per class as printed status: ground note: The lowest value is class 2 at 9 to 10 mm wall; the highest is class 3 at 9 to 10 mm wall. source: javadian2019 where: Table 2, column MC at 20 °C with 65% relative humidity - benchmark: moisture_content label: Moisture content at 45 °C and 80% relative humidity, range across classes value: 11.5 value_high: 15 bound: range unit: '%' scope: material conditions: species: Dendrocalamus asper (bamboo Petung) condition: 45 °C and 80% relative humidity method: Measured by the authors on 1 m subsection samples at the stated condition; one value per class as printed status: ground note: The paper says this condition was reached after 6 days for walls over 13 mm and after 3 days for walls under 13 mm. source: javadian2019 where: Table 2, column MC at 45 °C with 80% relative humidity; Results, Moisture Content (MC) paragraph on time to equilibrium - benchmark: elastic_modulus label: Young's modulus, range across radial and longitudinal positions (thesis abstract) value: 5 value_high: 40 bound: range unit: GPa scope: material conditions: species: Not stated in the abstract position: varied radially across the culm wall and along the culm test: tensile tests on culm, per the abstract (the test standard is not given there) method: Range quoted in the abstract of the MIT S.B. thesis; the full thesis PDF was not read in this run status: ground note: 'Caveat: the species and specimen form are not stated in the abstract, and the thesis PDF could not be downloaded in this run (HTTP 429), so the detail is unverified.' source: garcia2011 where: Abstract, sentence on Young's modulus and strength - benchmark: ultimate_tensile_strength label: Strength range across radial positions (thesis abstract) value: 100 value_high: 400 bound: range unit: MPa scope: material conditions: species: Not stated in the abstract position: varied radially across the culm wall basis: strength as printed in the abstract; the abstract does not name the test method: Range quoted in the abstract of the MIT S.B. thesis; the abstract says that tensile tests were run and that they follow the model trends status: ground note: The abstract says strength, not tensile strength. It is read here as tensile strength because the abstract reports tensile tests. source: garcia2011 where: Abstract, sentence on Young's modulus and strength - benchmark: ultimate_tensile_strength label: Highest tensile strength quoted for a named species (Bambusa tulda) value: 400 bound: exact unit: MPa scope: material conditions: species: Bambusa tulda (Bangladesh and adjoining India) basis: as high as 60,000 psi (400 MPa), as printed; test method and culm position not stated method: Single figure quoted in the Wikipedia article; secondhand, not from a primary test report status: ground note: Secondhand highest figure for one species; not a typical value for culm. source: wikipedia-bamboo where: Article text on bamboo tensile strength - benchmark: density label: Specific gravity, air-dried condition, mean (Sweet-Bamboo culms, Dendrocalamus asper) value: 0.77 unit: (specific gravity, no unit printed) bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), four culms from Prachinburi Province, Thailand condition: air-dried basis: specific gravity as printed in the thesis abstract; dimensionless, no unit printed method: Mean printed in the abstract of the 1997 Kasetsart University thesis; test standard not given in the abstract status: ground source: parkkeeree1997 where: Abstract, sentence on moisture content and specific gravity at air-dried condition - benchmark: moisture_content label: Moisture content at natural green condition, mean (Sweet-Bamboo culms, Dendrocalamus asper) value: 46 unit: '%' bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand condition: natural green, as printed in the abstract method: Mean printed in the abstract of the 1997 thesis status: ground note: moisture_content is not a canonical name in spores/property-canon.yaml, so the snake_case name is used. source: parkkeeree1997 where: Abstract, sentence on moisture content at natural green condition - benchmark: linear_shrinkage label: Linear shrinkage at air-dried condition, tangential direction, mean value: 2.53 unit: '%' bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand direction: tangential condition: air-dried, as printed in the abstract (drying from green to air-dried) method: Mean printed in the abstract of the 1997 thesis; one of three directions (tangential, radial, longitudinal) status: ground note: linear_shrinkage is not a canonical name in spores/property-canon.yaml, so the snake_case name is used. source: parkkeeree1997 where: Abstract, sentence on shrinkage at air-dried condition - benchmark: linear_shrinkage label: Linear shrinkage at air-dried condition, radial direction, mean value: 1.35 unit: '%' bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand direction: radial condition: air-dried, as printed in the abstract (drying from green to air-dried) method: Mean printed in the abstract of the 1997 thesis; one of three directions (tangential, radial, longitudinal) status: ground note: linear_shrinkage is not a canonical name in spores/property-canon.yaml, so the snake_case name is used. source: parkkeeree1997 where: Abstract, sentence on shrinkage at air-dried condition - benchmark: linear_shrinkage label: Linear shrinkage at air-dried condition, longitudinal direction, mean value: 0.21 unit: '%' bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand direction: longitudinal condition: air-dried, as printed in the abstract (drying from green to air-dried) method: Mean printed in the abstract of the 1997 thesis; one of three directions (tangential, radial, longitudinal) status: ground note: linear_shrinkage is not a canonical name in spores/property-canon.yaml, so the snake_case name is used. source: parkkeeree1997 where: Abstract, sentence on shrinkage at air-dried condition - benchmark: flexural_strength label: Modulus of rupture, mean (static bending, Sweet-Bamboo culms) value: 135 unit: MPa bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand test: static bending, as printed in the abstract basis: mean modulus of rupture; moisture condition for this value not stated separately in the abstract method: Mean printed in the abstract of the 1997 thesis; test standard not given in the abstract status: ground source: parkkeeree1997 where: Abstract, sentence on mean modulus of rupture - benchmark: flexural_modulus label: Modulus of elasticity in static bending, mean (Sweet-Bamboo culms) value: 13115 unit: MPa bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand test: static bending group in the abstract, printed next to the modulus of rupture basis: mean modulus of elasticity; the abstract prints it in the static bending sentence without a separate test standard method: Mean printed in the abstract of the 1997 thesis status: ground note: The abstract prints this value in the static bending sentence without naming the test mode separately, so it is read here as the bending modulus. source: parkkeeree1997 where: Abstract, sentence on mean modulus of rupture and modulus of elasticity - benchmark: ultimate_tensile_strength label: Tensile stress parallel to grain, mean (Sweet-Bamboo culms) value: 314 unit: MPa bound: exact scope: material conditions: species: Dendrocalamus asper Backer (Sweet-Bamboo), Thailand form: tension parallel to grain, as printed in the abstract basis: mean tensile stress parallel to grain method: Mean printed in the abstract of the 1997 thesis; test standard not given in the abstract status: ground source: parkkeeree1997 where: Abstract, sentence on tensile, compressive and shear stresses parallel to grain corrosion: - environment: Humid air at 45 °C and 80% relative humidity headline: At 45 °C and 80% relative humidity the culm samples held 11.5 to 15.0% moisture, against 8.4 to 11.2% at 20 °C and 65% relative humidity. effect: Moisture content rose in every class at 80% relative humidity. The paper says that condition was reached after 6 days for walls over 13 mm and after 3 days for walls under 13 mm, so thin-walled culms respond faster. rating: moderate conditions: exposure: culm samples conditioned at 45 °C and 80% relative humidity sample: Dendrocalamus asper, 1 m subsections basis: moisture content by class as printed in Table 2 source: javadian2019 where: Table 2 and Results, Moisture Content (MC) - environment: Rapid moisture change, wetting and drying headline: Rapid moisture change can make bamboo layers shrink or swell, and can cause layer-bond failure. effect: The paper says rapid moisture changes can cause severe shrinkage or expansion of bamboo layers, which in laminates or composites can produce layer-bond failure. It cites Lee et al. (1996), Zaidon et al. (2004) and Malanit et al. (2011). The paper gives no shrinkage percentage for the culm. rating: moderate conditions: basis: qualitative statement with citations; no test conditions given in the paper source: javadian2019 where: Introduction, paragraph on water absorption and dimensional stability - environment: Processing and service at moisture above 10% headline: The paper recommends moisture below 10% before culm is processed into composites. effect: The average moisture content of culms selected for processing should fall below 10%, to reduce excessive delamination and long-term degradation of the final composite. The authors dried their fibres in an oven at 80 °C until moisture content was below 10%. rating: moderate conditions: basis: recommendation by the authors from their moisture data; no long-term test reported source: javadian2019 where: Results, Moisture Content (MC), closing paragraph; Bamboo Composite Fabrication Using Material Correlation Relationships - environment: Ground contact or rain, untreated culm headline: Wikipedia says untreated bamboo in ground contact or rain breaks down quickly. No decay rate is given. effect: The article says bamboo exposed to ground contact or rain breaks down just as quickly as incorrectly harvested material, and that durability in construction depends on how well the material is handled. It gives no test standard, time or durability class. rating: unknown conditions: basis: general statement in a reference article; no test conditions source: wikipedia-bamboo where: Cultivation, leaching section - environment: Standing culm in the field, fungal colonisation headline: Wikipedia reports that fungal growth on culms leads to collapse and decay about 5 to 8 years later. effect: The article says fungal growth starts on the outside of the culm and, about 5 to 8 years later depending on species and climate, causes the culm to collapse and decay. This is an ecological account, not a durability test. rating: unknown conditions: basis: ecological description in a reference article; species and climate not specified in the source source: wikipedia-bamboo where: Ecology section - environment: Laboratory decay test with the brown-rot fungus Coniophora puteana, untreated culm sections (Gigantochloa atroviolacea and Phyllostachys pubescens), 32 weeks headline: In a 32-week laboratory jar test, untreated bamboo lost up to 8.4% of its mass to the brown-rot fungus Coniophora puteana. effect: The paper says maximum mass loss of bamboo was 8.4%, and that P. pubescens was more decayed than G. gigantochloa. The paper states that most earlier investigations found bamboo degradation due to white and soft rot fungi, with brown-rot species less aggressive, so this brown-rot result runs against that general pattern in this test. rating: moderate conditions: method: vermiculite jar test (fungus cellar and agar tests are separate methods in the paper), 32 weeks at 20±2 °C and 65±5% relative humidity basis: mass loss after 32 weeks of incubation, as printed; not an EN 350 or ISO 22156 durability class source: wei2013 where: Results, paragraph on mass loss by Coniophora puteana (Figure 4) - environment: Laboratory decay test with the white-rot fungus Schizophyllum commune, untreated culm sections, 32 weeks headline: In the same 32-week test, untreated bamboo lost at most 4.6% of its mass to the white-rot fungus Schizophyllum commune. effect: The paper says maximum mass loss of bamboo was only 4.6% for this fungus, and that the paper found this fungus common on bamboo culms during storage and use. The paper also says most investigations found bamboo degradation was caused by white and soft rot fungi. rating: low conditions: method: vermiculite jar test, 32 weeks at 20±2 °C and 65±5% relative humidity basis: mass loss after 32 weeks of incubation, as printed; not an EN 350 or ISO 22156 durability class source: wei2013 where: Results, paragraph on mass loss by Schizophyllum commune (Figure 3); Introduction risks: hazards: - text: Dust from cutting, sanding, planing or drilling is the main health concern in the vendor SDS for a bamboo strand flooring product. The SDS says dust can trigger respiratory conditions or pre-existing allergies. ghs: [] source: ambient-msds where: Sections III and IV (hazard identification and first aid) - text: The same SDS says bamboo dust can cause respiratory difficulties, nasal irritation, cough or sneezing in sensitive people, and that no tests have shown long-term respiratory effects or cancer from bamboo dust. ghs: [] source: ambient-msds where: Sections III and IV - text: The SDS prints an OSHA PEL-TWA of 15 mg/m3 for total dust for the bamboo ingredient, which is 94 to 95% of that product. ghs: [] source: ambient-msds where: Section II (ingredients) failure_risks: - mode: Dimensional change and layer-bond failure during moisture swings trigger: Rapid moisture change from wetting or drying consequence: Shrinkage or expansion of bamboo layers, which in laminates or composites can cause layer-bond failure (Javadian et al. 2019, citing earlier work). The paper gives no shrinkage percentage for the culm. severity: moderate source: javadian2019 where: Introduction, paragraph on water absorption and dimensional stability - mode: Lower strength and stiffness in thick-walled culms trigger: Culm classes 5 to 7, with thicker walls consequence: The paper reports that in classes 5 to 7 both tensile strength and modulus of elasticity decrease as wall thickness increases. severity: moderate source: javadian2019 where: Results, Modulus of Elasticity in Tension, and Table 4 - mode: Fungal decay of untreated culm trigger: Ground contact or rain consequence: Wikipedia says untreated culm in ground contact or rain breaks down quickly. The article gives no time or decay rate. source: wikipedia-bamboo where: Cultivation, leaching section handling: - text: Dry processed culm fibre to below 10% moisture before use. The authors oven-dried their fibres at 80 °C until moisture content was below 10%. source: javadian2019 where: Bamboo Composite Fabrication Using Material Correlation Relationships - text: Where cutting or sanding makes dust, use local exhaust or a dust respirator and goggles if dust limits are exceeded. The SDS gives this advice for the flooring product. source: ambient-msds where: Sections VI and VIII - text: For the finished flooring product, the SDS warns that excessive moisture, condensation or water vapour can cause warping or popping of boards. source: ambient-msds where: Section X (stability and reactivity) mitigations: - text: Measure culm geometry and specific density before choosing culm for use. The paper proposes both as rapid, non-destructive quality checks. source: javadian2019 where: Abstract uses: - application: structures device: Small village housing and construction in Java example: The paper says Dendrocalamus asper is widely available in Java and mostly used for construction of small housing in local villages. source: javadian2019 where: Materials and Methods, Bamboo Species - application: structures device: Bamboo fibre composite reinforcing bar for concrete (laboratory prototype, made from processed fibre, not culm) example: The authors bonded processed bamboo fibre bundles in epoxy and tested the bars in pull-out and beam tests, to validate the approach for structural concrete. source: javadian2019 where: Section Bamboo Composite Fabrication, and Table 13 - application: structures device: Strand-woven bamboo flooring (engineered product, not culm) example: The vendor SDS covers prefinished solid strand woven bamboo flooring for residential and commercial indoor use. source: ambient-msds where: Section I (product identification and applications) supply: - subject: Bamboo, area of bamboo forest and other land by country abundance: FAO reports that bamboo may total more than 36 million hectares worldwide in its 2005 assessment. Asia's reporting countries held 23,620 thousand ha of bamboo forest in 2005, with India at 11,361 thousand ha and China at 5,444 thousand ha. producers: [] critical_lists: [] recycling: Not found in any source we hold. substitutes: [] source: fao2007 where: Table 4 (extent of bamboo forest by country, 2005 column) and the text before it - subject: Bamboo culm, growth and renewal abundance: Javadian et al. say bamboo reaches its full height of 20 to 30 m within only a few months, which makes the stem renewable on a short cycle. producers: [] critical_lists: [] recycling: Not found in any source we hold. substitutes: [] source: javadian2019 where: Introduction, first paragraph - subject: Bamboo production statistics, global and by country abundance: FAO states that bamboo production data are not available at the global level. The only country tonnage on the page is China's dry bamboo shoot output of 858 083 tonnes in 2017, one product category from China's statistical yearbook, not total bamboo culm. producers: [] critical_lists: [] recycling: Not found in any source we hold. substitutes: [] source: fao-bamboo-stats where: Statistics page, paragraphs on global production data and on China's dry bamboo shoots media: [] documents: - title: Mechanical Properties of Bamboo Through Measurement of Culm Physical Properties for Composite Fabrication of Structural Concrete Reinforcement (Frontiers in Materials 6:15, open access) type: paper url: https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2019.00015/pdf year: 2019 - title: Radial and longitudinal variation of the mechanical properties of bamboo (MIT S.B. thesis, DSpace record) type: paper url: https://dspace.mit.edu/handle/1721.1/101858 year: 2011 - title: World bamboo resources (FAO Non-Wood Forest Products 18) type: report url: https://www.fao.org/4/a1243e/a1243e00.pdf year: 2007 - title: 'Material Safety Data Sheet: Strand Bamboo (Ambient Bamboo Floors, prefinished solid strand woven bamboo flooring)' type: sds url: https://www.ambientbp.com/pdf/MSDS_StrandBamboo.pdf - title: Method to test fungal degradation of bamboo and wood using vermiculite as reservoir for moisture and nutrients (Wei, Schmidt and Liese; Maderas. Ciencia y Tecnologia 15(3), open access) type: paper url: https://www.redalyc.org/pdf/485/48528861008.pdf year: 2013 - title: Physical and mechanical properties of wood from sweet bamboo culms (Dendrocalamus asper Backer), Kasetsart University thesis, abstract read on AGRIS type: report url: https://agris.fao.org/search/en/records/6472350208fd68d546000dc7 year: 1997 - title: Bamboo production statistics, Non-Wood Forest Products statistics page (FAO) type: database url: https://www.fao.org/forestry/nwfp/statistics/bamboo/en gaps: - No space-environment data (vacuum, radiation, atomic oxygen, UV, thermal cycling, outgassing) for bamboo culm in any source read in this run. No flight or ground test found. - Durability classes for untreated culm against decay fungi and powder-post beetles (for example EN 350 or ISO 22156 classes) not read. The ResearchGate and ScienceDirect pages returned HTTP 403. - 24-hour water absorption and thickness swelling for untreated raw culm not found in an open source we could read. The open Dendrocalamus asper papers found report treated or densified samples only. - Shrinkage is known only from the 1997 Thai thesis abstract, which measures air-dried wood from sweet bamboo culms (tangential 2.53%, radial 1.35%, longitudinal 0.21%). The thesis full text was not readable, and the Frontiers paper states the moisture effect but gives no shrinkage number. - Country production shares not found. FAO 2007 gives bamboo area, not production, and the FAO statistics page says bamboo production data are not available at the global level. Web search snippets with production shares conflicted and were not used. - Durability class for untreated culm (EN 350, EN 113 class or ISO 22156) not found. The Wei et al. (2013) jar test gives mass loss after 32 weeks for two bamboo species, not a durability class. Search snippets that report a six-year ground-contact trial were not read in full and are not used. - Critical-mineral lists (USGS, EU) not checked. Bamboo is a plant, not a mineral, so no list entry was read. - Recycling and end-of-life not found in any source we hold. - No hazard classification for raw culm (SDS or GHS) found. The only hazard data are a vendor SDS for an engineered strand-bamboo flooring product, and the dust limit and sensitisation statements come from that product. - The MIT thesis PDF could not be downloaded in this run (HTTP 429). Only the abstract on the DSpace record was read, so the species, specimen form and test standard for the 5 to 40 GPa and 100 to 400 MPa ranges are unverified. - Data for Dendrocalamus asper (Petung) come from one paper and a 1997 thesis abstract (Thai sweet bamboo, same species name). The thesis full text and the Hamburg dissertation on D. asper were not readable in this run (HTTP 403). Other bamboo species are not covered, apart from the single Bambusa tulda figure in Wikipedia, which has no test details. - Thermal properties (thermal conductivity, specific heat, thermal expansion) not found in any source read in this run. - Powder-post beetle attack and treatment performance not read in a fetched source. Search snippets on beetle attack and borate treatment were not verified. - The bamboo fibre epoxy composite data in Javadian et al. (Tables 11 and 13) describe a composite, not the culm, and are left out of the culm properties. - moisture_content is not a canonical name in spores/property-canon.yaml, so the snake_case name is used. sources: javadian2019: title: Mechanical Properties of Bamboo Through Measurement of Culm Physical Properties for Composite Fabrication of Structural Concrete Reinforcement id: doi:10.3389/fmats.2019.00015 (Front. Mater. 6:15) url: https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2019.00015/pdf year: 2019 kind: paper license: CC BY (as published by Frontiers; not reproduced here) garcia2011: title: Radial and longitudinal variation of the mechanical properties of bamboo (S.B. thesis, Department of Materials Science and Engineering, MIT) id: MIT DSpace handle 1721.1/101858 url: https://dspace.mit.edu/handle/1721.1/101858 year: 2011 kind: report license: MIT DSpace record (abstract read; full PDF not read in this run) fao2007: title: World bamboo resources (FAO Non-Wood Forest Products 18, thematic study for the Global Forest Resources Assessment 2005) id: FAO NWFP 18 (a1243e) url: https://www.fao.org/4/a1243e/a1243e00.pdf year: 2007 kind: report license: FAO publication, cited not reproduced wikipedia-bamboo: title: Bamboo (Wikipedia article, en.wikipedia.org) id: Wikipedia article, read 2026-11-01; not a primary source url: https://en.wikipedia.org/wiki/Bamboo kind: web license: CC BY-SA 4.0 (Wikipedia) ambient-msds: title: 'Material Safety Data Sheet (MSDS): Strand Bamboo, prefinished solid strand woven bamboo flooring (Ambient Bamboo Floors)' id: Vendor SDS, undated; covers an engineered flooring product url: https://www.ambientbp.com/pdf/MSDS_StrandBamboo.pdf kind: datasheet license: supplier document, cited not reproduced wei2013: title: Method to test fungal degradation of bamboo and wood using vermiculite as reservoir for moisture and nutrients id: doi:10.4067/S0718-221X2013005000027 (Maderas. Cienc. Tecnol. 15(3):349-356) url: https://www.redalyc.org/pdf/485/48528861008.pdf year: 2013 kind: paper license: Open access journal article (Redalyc); cited not reproduced parkkeeree1997: title: Physical and mechanical properties of wood from sweet bamboo culms (Dendrocalamus asper Backer), Kasetsart University thesis id: AGRIS record 6472350208fd68d546000dc7 (thesis, 89 leaves); full text not readable in this run url: https://agris.fao.org/search/en/records/6472350208fd68d546000dc7 year: 1997 kind: report license: AGRIS bibliographic record (abstract read); cited not reproduced fao-bamboo-stats: title: Bamboo production statistics, Non-Wood Forest Products statistics page (FAO) id: FAO NWFP statistics, bamboo page (no date printed on the page) url: https://www.fao.org/forestry/nwfp/statistics/bamboo/en kind: web license: FAO web page, cited not reproduced license: CC-BY-4.0 updated: '2026-11-01' review: status: draft method: assistant checked_values: 22 unreachable: 0 caveats: 4 note: 'Written 2026-11-01 by an AI assistant from pages fetched in this run: the Frontiers PDF (text and tables read with pdftotext), the FAO PDF, the MIT DSpace abstract, the Wikipedia article and a vendor SDS. Deepened 2026-11-02 with the Redalyc PDF (Wei et al. 2013, decay test mass loss), the AGRIS abstract of a 1997 Thai thesis on D. asper culm wood, and the FAO bamboo statistics page. Values copied as printed. verify-values found all 22 values in their cited sources. The MIT thesis PDF was rate-limited, so only its abstract was read.' story: recipe: line: Bamboo is a natural composite. Cellulose fibres reinforce a lignin matrix, and the paper says the fibres act like the reinforcement in fibre-reinforced polymer composites (Javadian et al. 2019). parts: - name: Cellulose fibres role: Carry most of the mechanical load. Their density is higher at the outer wall and at the top of the culm, which raises stiffness and strength there. source: javadian2019 where: Introduction, microstructure paragraph; Results, Modulus of Rupture - name: Lignin matrix role: The matrix the fibres reinforce. Thicker walls carry more lignin relative to fibre, which the paper links to lower stiffness in large culms. source: javadian2019 where: Results, Modulus of Elasticity in Tension - name: Parenchyma matrix role: The tissue in which the vascular bundles sit. The supporting fibres surround the bundles. source: javadian2019 where: Introduction, microstructure paragraph risk_groups: - title: For people level: 1 verdict: Dust can irritate sensitive people lead: No hazard classification for raw culm was found. The only hazard sheet held is for an engineered bamboo flooring product. points: - label: Dust line: Dust from cutting, sanding or planing can trigger respiratory conditions or allergies, according to the vendor sheet. The sheet prints an OSHA limit of 15 mg/m3 for total dust for the bamboo ingredient. - label: Long term line: The same sheet says no tests have shown long-term respiratory effects or cancer from bamboo dust. That is the vendor's statement, not a peer-reviewed finding. - title: If the culm takes up water level: 2 verdict: Moisture changes dimensions lead: Moisture content tracks humidity, and rapid change can damage layered parts. points: - label: Humid air line: At 45 °C and 80% relative humidity the samples held 11.5 to 15.0% moisture. At 20 °C and 65% relative humidity they held 8.4 to 11.2%. - label: Layers line: Rapid moisture change can cause shrinkage or swelling of bamboo layers and layer-bond failure in laminates, the paper says. - label: Ground contact line: Wikipedia says untreated bamboo in ground contact or rain breaks down quickly. The article gives no time or decay rate. - title: Handling and storage points: - label: Moisture before use line: The authors dried their fibres in an oven at 80 °C until moisture content was below 10%. - label: Dust line: Where cutting or sanding makes dust, the vendor sheet advises local exhaust and a dust respirator if dust limits are exceeded. why: Bamboo culm is the stem of a bamboo grass, which reaches its full height within a few months (Javadian et al. 2019). It is a natural composite. The paper measures how its density, stiffness and strength change with culm diameter, wall thickness and moisture, so a culm can be judged before it is used in building or in fibre composites. uses: - where: Local building in Java line: The paper says Dendrocalamus asper is widely available in Java and mostly used to build small village houses. - where: Concrete reinforcement research (fibre composite, not culm) line: The same authors made bamboo fibre composite bars and tested them in concrete beams, as a laboratory check of their approach. can_do: - label: Stiffness in tension benchmark: elastic_modulus line: In tension, culm samples reached 18,140 to 28,230 MPa, depending on culm class (Table 5). - label: Tensile strength benchmark: ultimate_tensile_strength line: Tensile strength along the fibre ranged from 193 to 340 MPa across culm classes (Table 4). - label: Bending strength benchmark: flexural_strength line: Modulus of rupture ranged from 121 to 209 MPa in two-point flexure (Table 6). - label: Bending stiffness benchmark: flexural_modulus line: Modulus of elasticity in flexure ranged from 9,375 to 14,279 MPa (Table 7). - label: Moisture benchmark: moisture_content line: Moisture content was 8.4 to 11.2% at 20 °C and 65% relative humidity, and 11.5 to 15.0% at 45 °C and 80% relative humidity (Table 2). compare: In Table 8 of Javadian et al. (2019), citing Green et al. (1999), bamboo Petung has a higher mean tensile strength along the fibre than Balau, Sumatran Pine and Indonesian Rosewood. Its mean modulus of elasticity is higher than all three except the top of the Balau range, and its mean modulus of rupture is higher than all of them. The timber figures are not copied into this profile, so read them in the source table. compare_rows: - label: Specific density (oven-dry, range) benchmark: density - label: Tensile strength along the fibre benchmark: ultimate_tensile_strength - label: Modulus of elasticity in tension benchmark: elastic_modulus handling: - Dry culm fibre to below 10% moisture before processing, as the paper recommends. - Use dust control and a dust respirator where cutting or sanding makes dust (vendor sheet). - Keep finished bamboo products dry, because excessive moisture can warp or pop boards (sheet for the flooring product). good_for: - Local building where the stem is grown nearby, as the paper reports for small houses in Java. - Fibre composites that use the stem's fibre; the paper's bamboo fibre reinforcement was tested in concrete beams in the laboratory. watch_out: - Strength and stiffness fall in thick-walled culms and change from the outer wall to the inner wall. - Rapid moisture change can cause shrinkage, swelling and layer-bond failure in laminates. - Laboratory jar tests over 32 weeks gave a maximum mass loss of 8.4% (Coniophora puteana) and 4.6% (Schizophyllum commune) for untreated bamboo, which is a test result and not a durability class. - No space data, no durability rating and no raw-culm hazard data were found. verdict: The record supports bamboo culm as a structural stem with measured stiffness and strength in the ranges the paper reports. Its values change with culm class and with humidity, so each culm needs grading before use.