This standard specifies the terminology, technical requirements, measurement units, measurement tools and measurement methods for commercial bamboo (Phyllostachys pubescens) timber. This standard applies to bamboo timber used directly as building scaffolding, scaffolding, and processed into bamboo finished products, semi-finished products and paper pulp. Bamboo timber for other purposes can be implemented as a reference under the same conditions. GB/T 2690-2000 Bamboo Timber GB/T2690-2000 Standard download decompression password: www.bzxz.net

GB/T2690—2000
This standard is a revision of GB/T2690—1981 "Bamboo". The main changes are as follows: - The original standard name "Bamboo" is now changed to "Bamboo Material". Technical requirements: The size and material indicators are divided into direct use, processing use, and pulp use according to the purpose. The diameter size of 4~5cm and 6cm was merged into ≤6cm, 7~8cm was changed to 7~9cm, and 9cm and above was changed to ≥10cm. The bending arch height limit in the material index was changed from 10% to 8%; the rupture limit was changed from 3 nodes to 2 nodes; the limit of external defects was increased.
The diameter inspection position was changed from 1.7m to 1.5m, and the inspection was performed by 1cm, and the less than 1cm was rounded up. - Added definitions and defect inspection methods.
This standard will replace GB/T2690-1981 from the date of implementation. This standard was proposed by the State Forestry Administration.
This standard was drafted by the Fujian Provincial Forestry Department. The main drafters of this standard are Lin Zaizhi, Luo Jiaji, Lin Dajia and Li Jingqing. 48
1 Scope
National Standard of the People's Republic of China
Bamboo timber
Bamboo timber
GB/T 2690—2000
Replaces GB/T2690—1981
This standard specifies the terminology, technical requirements, measurement units, measurement tools and measurement methods for commercial bamboo (Phyllostachys pubescens) timber. This standard applies to bamboo timber used directly as building scaffolding and scaffolding, as well as bamboo timber processed into bamboo finished products, semi-finished products and paper pulp. Bamboo timber for other purposes can be implemented as a reference under the same conditions. 2 Definitions
This standard adopts the following definitions.
2.1 Curvature
The phenomenon that the central axis of the bamboo material deviates from the same straight line. 2.2 Withered
During the growth period, the bamboo was damaged by pests and diseases and died before felling. 2.3 Insect damage
Due to insect damage, the surface of the material appears yellow or white powder, or there are dense small insect holes. 2.4 Discoloration by mould Due to poor storage, the bamboo material is eroded by mold, and the surface of the material appears spots or mold and deteriorates, the fiber is damaged, and the toughness is reduced. 2.5 Insect hole
The hole formed by insect damage.
2.6 Shrinkage knot
During the growth period, the bamboo is damaged by pathogens and insects or the influence of adverse environment, which destroys its normal growth law, resulting in the shortening of the distance between bamboo nodes or the local expansion.
2.7 Crack
The end surface of bamboo is subjected to external force, resulting in cracks between fibers. 2.8 External wound
Local damage to the surface of bamboo during felling and transportation. 3 Technical requirements
3.1 Requirements for bamboo for direct use and processing
The bamboo is over 6 years old and has been pruned. 3.2 Size
3.2.1 See Table 1 for bamboo for direct use and processing. Approved by the State Administration of Quality and Technical Supervision on May 19, 2000, implemented on August 1, 2000
≤6cm
≥10cm
GB/T 2690 - 2000
3.2.2 There is no limit on the length, diameter and age of bamboo for pulping. 3.2.3 Direct bamboo materials should keep their natural length in principle. 3.3 Material index
3.3.1 Direct bamboo materials and processed bamboo materials are shown in Table 2. Table 2
Defect name
Calculation methodbZxz.net
Maximum bending arch height shall not exceed the horizontal length of the inner curve Within the range of the measuring ruler
Within the measuring ruler range
Within the measuring ruler range
Within the measuring ruler range
Within the measuring ruler range The smallest diameter of the insect hole exceeding 5 mm within the measuring ruler range shall not exceed
Within the measuring ruler range, both ends shall not exceed
Within the measuring ruler range, the length of the solitary length shall not exceed the circumference of the circle The maximum length at the longitudinal position shall not exceed the measuring ruler range The depth shall not exceed
Note: Defects not listed in this table shall not be counted.
3.3.2 Except for dryness, change and insects, bamboo materials for pulping are not limited to other defects. 3.4 The technical requirements of special bamboo materials shall be agreed upon by the supply and demand parties. 4 Measurement units
4.1 Direct timber and processed timber
Length is in meters (m); diameter is in centimeters (cm); quantity is in roots. 4.2 Pulp bamboo is in tons (t)
5 Inspection tools
5.1 Length inspection shall be carried out using a rod ruler or tape measure with metric scale. 5.2 Diameter inspection shall be carried out using a circumference ruler or caliper produced by a designated manufacturer approved by the quality and technical supervision department. 6 Measurement method
6.1 Length measurement
≥2 cm
≥>3cm
≥4cm
Allowable limit
Not allowed
Not allowed
Not allowed
Not allowed
2 nodes
Measure from the upper edge of the cut at the root end (for water-transported bamboo with water holes, the inner side of the water holes should be used for calculation) to the specified tip diameter, and measure in 0.5m steps. 6.2 Diameter measurement
Measure from the upper edge of the cut at the root end to 1.5m. If a bamboo node or a shortened node is encountered, the measurement should be moved toward the tip end to the normal position, and 1cm should be measured in 50
GB/T 2690 - 2000
steps. Any value less than 1cm should be rounded up. When using a caliper, the average of its long and short diameters after rounding off is used as the gauge diameter; when using a girder, the converted diameter after rounding off is used as the gauge diameter.
6.3 Defect measurement
6.3.1 Bending
Compare the maximum bending arch height within the gauge length range with the horizontal length of the inner curve. For multi-faceted bending, the one with the largest arch height shall prevail. 6.3.2 Drying
The normal color of bamboo material changes, light brown or purple-black spots appear at the main tip or node fork, the bamboo pole becomes slightly sunken or longitudinally cracked, and water accumulates in the bamboo node.
6.3.3 Insect frog
Observe the material surface with the naked eye for yellow or white powder or dense small insect eyes. 6.3.4 Mildew
Observe the material surface with the naked eye for mildew spots or deterioration. 6.3.5 Insect holes
Calculate the minimum diameter, whether it exceeds 5mm. 6.3.6 Joint reduction
Calculate the number of joint reductions.
6.3.7 Cracks
The cracks at both ends of the bamboo shall not exceed the range of two joints. 6.3.8 External injuries
Calculate the length, width and depth of the damage respectively, and no one of them is allowed to exceed the limit. 51
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