ISO 22157:2019

ISO 22157:2019 pdf free.Bam boo structures —— Determination of physical and mechanical properties of bamboo culms —— Test methods.
5 General requirements
5.1 Temperature and humidity
Unless required by specific conditioning protocols, test specimens shall be stored, conditioned and tested in an environment having a temperature range of (23 ± 3) °C, and relative humidity range of
However, if tests results are to be used in the same environmental conditions in which testing took place, or if the laboratory is unable to follow the standard, storage, conditioning and testing under ambient temperature and relative humidity is permitted. The values of the temperature (±3 °C) and the relative humidity (±5 %) for the laboratory shall be recorded in the test report, alongside the moisture content determined for individual specimens.
5.2 Rate of load application
The rate of load application of the testing machine shall be selected such that failure is reached within (300 ± 120) s. Tests that fail in less than 30 s shall be removed from analysis. The load shall be applied continuously without interruption at the required rate throughout the test. For tests run in displacement control, the rate of traverse of the movable head of the testing machine shall be the free running or no-load speed of the head for mechanical drive type machines, and the loaded head speed for hydraulic or servo-hydraulic driven testing machines. The time to failure for each individual specimen shall be recorded in the test report.
5.3 Calibration
All apparatus and testing equipment used in obtaining data shall be calibrated at sufficiently frequent intervals to ensure accuracy. A record of errors observed before calibration, the date and time of calibration and observations following calibration shall be maintained.
6 Sampling and storage of specimens
6.1 Sampling
Sampling should be representative of the population which test results are intended to represent and be appropriate for the objective of the testing program. Sampling methodology shall be included in the test report.
Bamboo material for any particular species shall be taken:
— in the case of tests on properties for commercial purposes: from a number of different localities, representative of different growth conditions throughout the geographical range of the species;
— in the case of quality control as required in a strength grading protocol orstandard: from a randomly selected sample from a batch as required by the protocol or standard.
From each locality, the selection, marking, etc., of the different consignments, as well as all the details of the various clumps and cuims, shall be reported.
Culms are to be cut to length taking care to record the provenance of a specimen along the culm in accordance to 6.3. For specimens that are to be used to determine bending strength, refer to Clause 12 for minimum lengths.
8 Density
8.1 General
This clause specifies three methods for determining the density, as mass by volume, of bamboo. For most scientific and commercial applications, determining the density at the time of test, Ptest’ is adequate, and shall be calculated from the mass and volume at the time of the test. To enable comparison between reported values, the density at time of test should be adjusted to the density at 12 % moisture content, P12•
For some scientific purposes and accurate comparison between reported values, basic density, p. is most appropriate. It is determined from the oven-dry mass and green volume, since these remain unchanged irrespective of environmental conditions.
8.2 Apparatus
8.2.1 Measuring instrument, capable of determining the dimensions of the test pieces with a precision of 0,1 mm.
8.2.2 Balance, suitable to weigh a specimen with a precision of at least 0,5 % of the specimen mass.
.2.3 Equipment for the determination of the moisture content in accordance with 7.1.ISO 22157 pdf download.

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