This standard outlines the established protocols for collecting timber scantlings from storage depots and their subsequent transformation into test specimens for evaluating mechanical and physical properties. It serves as a guideline for professionals ensuring that sampling is representative and that specimens are properly marked, conditioned, and prepared for accurate strength and durability assessments.
Overview
This standard outlines the established protocols for collecting timber scantlings from storage depots and their subsequent transformation into test specimens for evaluating mechanical and physical properties. It serves as a guideline for professionals ensuring that sampling is representative and that specimens are properly marked, conditioned, and prepared for accurate strength and durability assessments.
Audience
Contents
Structure
The scope covers definitions aligned with established timber terminology standards and details the sampling and selection criteria for timber scantlings. It specifies lot sizes and corresponding sample quantities, emphasizing selection of sound, defect-free, straight-grained scantlings. Sampling employs random methods ensuring representativeness, with sample sizes guided by inspection tables.
This section lists essential referenced standards including those defining timber terms, technology, and sampling inspection procedures. It summarizes requirements for scantling quality and rationalizes sample sizes based on lot quantities, ensuring compliance with timber testing norms.
Details scantling dimensions (approximately 13 cm square cross-section by 1.5 m length) and sampling quantities according to lot sizes. It also describes proportional and random selection methods for lots exceeding standard sizes to ensure representativeness.
Outlines protective packing methods to prevent moisture infiltration and mechanical damage during transportation. Advises prompt testing of samples or, if necessary, storage with appropriate preservative treatments to avoid deterioration in accordance with specified standards.
Specifies marking scantlings at one end with identifying information and describes cutting each scantling longitudinally into four sticks of 6 cm by 6 cm cross-section for testing. Highlights the importance of timely conversion and adherence to preservation treatments when storage is required.
Describes the conditioning environment—maintaining temperature around 27 ± 2°C and relative humidity near 65 ± 5% for about one week—to stabilize moisture content. After conditioning, specimens are planed to 5 cm square cross-section before further processing for mechanical tests.
Details sample size requirements, emphasizing random selection of at least 10% of scantlings (minimum 20) for testing, aligned with sampling inspection tables. Specifies specimen lengths according to test types and provides guidance on utilizing uninjured portions of prior test specimens when necessary.
Provides comprehensive methodology for random sampling and specimen selection as per referenced standards. Includes considerations for growth ring orientation, visible defects, and specimen dimensions tailored to different mechanical tests, ensuring representative and reliable test results.
Frequently Asked
Timber scantlings must be selected with dimensions around 13 cm by 13 cm in cross-section and 1.5 m in length, with one scantling chosen per log or converted timber. Selection criteria demand soundness, straight grain, and absence of decay, heart center, large knots, twisted grain, or defects impairing strength. Sampling should include at least 10% of the total scantlings, with a minimum of 20 pieces, chosen randomly according to recognized standards to ensure representativeness and reliability in testing.
Each timber scantling must be marked at one end with identifying details including depot name and location (using standard abbreviations), timber species abbreviation, consignment number, and scantling number. Initially, scantlings are cut to a cross-section of 13 cm by 13 cm and length of 1.5 m, then longitudinally sawn into four sticks measuring 6 cm by 6 cm in cross-section. These markings ensure traceability and proper identification throughout the testing process.
Before conversion into test specimens, timber sticks must be conditioned in an environment maintained at approximately 27 ± 2°C temperature and 65 ± 5% relative humidity for about one week to stabilize moisture content. After conditioning, the sticks are planed to a 5 cm by 5 cm cross-section on all sides and then cut into test specimens. If immediate testing is not feasible, samples must be stored using preservative treatments compliant with relevant standards to prevent deterioration.
Test specimens are selected from timber sticks prepared by longitudinally sawing the scantlings. Selection involves randomly choosing at least 10% of the total scantlings, with a minimum of 20 specimens, ensuring representativeness as per established sampling guidelines. Specimens must adhere to specified dimensions and lengths based on the type of mechanical test, with consideration given to growth ring orientation and absence of visible defects. Testing should occur promptly or with proper storage measures to maintain specimen integrity.
Timber samples must be packed securely to prevent moisture penetration and mechanical damage during transit. Use waterproof and shock-absorbent materials to protect the scantlings. Upon receipt, samples should be tested as soon as possible; if storage is necessary, maintain controlled conditions to avoid deterioration, including application of preservative treatments as specified by relevant standards. Careful handling during loading and unloading is crucial to preserve sample quality.
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