【国外标准】 Standard Test Method for Determining the Change in Mass of Rolled Erosion Control Products When Submerged in Water

5.1 Rolled erosion control products are intended to protect seed beds from erosion and provide an environment that encourages seed germination. Maintaining a moist environment by gradually releasing absorbed moisture helps provide a beneficial growth environment. The ability of a product to absorb moisture is commonly specified. This test method can be used for quality control and to determine product conformance to a specification.5.2 Change in mass of RECPs submerged in water may be used to control the quality of many RECPs. Change in mass of RECPs submerged in water has not been proven to relate to field performance for all materials.5.3 The change in mass of RECPs submerged in water may vary considerably depending on the composition of the materials used in the product or due to inconsistency within the product. This test method enables the characterization and control of product consistency.5.4 This test method may be used to determine the effect of different component materials and makeup of RECPs on the change in mass when submerged in water.5.5 This test method may be used for acceptance testing of commercial shipments of RECPs. Comparative tests as directed in 5.6 may be advisable.5.6 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier shall conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the evaluation of bias. As a minimum, the two parties shall take a group of test specimens that are as homogeneous as possible and that are formed from a lot of material of the type in question. The test specimens shall be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories shall be compared using Student’s t-test for unpaired date and an acceptable probability level chosen by the two begun. If bias is found, either its cause must be corrected, or the purchaser and supplier must agree upon the known bias.NOTE 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 This test method measures the change in mass of a rolled erosion control product when specimens are submerged in water for a prescribed period of time. The change in mass is reported as a percentage of the original dry mass of the specimen.1.2 Units—The values stated in either SI units or inch-pound units [given in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.1.2.1 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This practice implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit of mass. However, the use of balances and scales recording pounds of mass (lbf) or recording density in lbm/ft3 shall not be regarded as nonconformance with this standard.1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this test method.1.3.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of these test methods to consider significant digits used in analysis methods for engineering data.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.