1.1 本试验方法涵盖了渗透系数的实验室测量（也称为 渗透系数 )使用刚性壁渗透仪从废轮胎材料中获得的水饱和样品。本方法涵盖的废轮胎材料包括实践中描述的轮胎碎片、轮胎碎片和轮胎衍生骨料（TDA） D6270 粒径约为12至305 mm。本标准不包括整个废轮胎。在给定的碎片垂直压力下，导水率和碎片大小之间没有明显的趋势 ≥ 50毫米 ( 1. ) . 2. 1.2 试验中可使用单环或双环渗透计。考虑到并防止渗透剂沿渗透计侧壁短路，双环渗透计可能优于单环渗透计。侧壁流动的影响在高应力下以及当孔直径小于颗粒尺寸的6倍时更为显著 ( 1. ) . 1.3 试验方法在恒定水头条件下使用。 1.4 试验方法中使用水作为渗透剂。 1.5 试验方法 D2434 也可用于在刚性壁渗透仪中，在恒定水头条件下，测定尺寸小于19 mm的废轮胎衍生材料的导水性。方法 D2434 包括使用单环渗透计。 1.6 以国际单位制表示的数值应视为标准。在美国，导水率传统上以厘米/秒表示，即使导水率的官方国际单位为米/秒。 1.7 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 本试验方法用于测量在施加的水力梯度下，从废轮胎中提取的材料的初始饱和样品中的一维垂直水流。废轮胎的各种土木工程应用都需要导水性。 4.2 样品应在单位重量和代表现场条件的表土压力下进行测试。文献数据表明，随着垂直压力的增加，导水率降低 ( 1. ) . 4.3 除了单环渗透计外，本试验方法还包括使用双环渗透计。双环渗透仪可以最大限度地减少侧壁泄漏对试样测量导水率的潜在不利影响。使用带有内径小于渗透计直径的内环和两个流出口（一个来自内环，一个来自内环和渗透计之间的环形空间）的底板，可以将来自试样中心部分的流量与渗透计侧壁附近的流量分离。 4.4 假设达西定律有效，假设水流为层流（雷诺数小于约2000–3000），假设导水率基本上与水力梯度无关。达西定律的有效性可以通过测量三个水力梯度下试样的导水率来评估。放电速度( v = k × 一、 )根据应用的水力梯度绘制。如果得出的关系是线性的，并且测得的导水率值相似（i。 e、 ，25以内 %), 那么可以认为达西定律是有效的。 注1: 本标准产生的结果的质量取决于使用本标准的人员的能力以及设备和设施的适用性。符合实践标准的机构 D3740 通常认为能够胜任和客观的测试/采样/检查等。本标准的用户应注意遵守惯例 D3740 本身并不能保证可靠的结果。可靠的结果取决于许多因素； 实践 D3740 提供了一种评估其中一些因素的方法。

1.1 This test method covers laboratory measurement of the hydraulic conductivity (also referred to as coefficient of permeability ) of water-saturated samples obtained from materials derived from scrap tires using a rigid-wall permeameter. The scrap tire materials covered in this method include tire chips, tire shreds, and tire derived aggregate (TDA) as described in Practice D6270 with particle sizes ranging from approximately 12 to 305 mm. Whole scrap tires are not included in this standard. A clear trend between hydraulic conductivity and shred size has not been established at a given vertical pressure for shreds ≥ 50 mm ( 1 ) . 2 1.2 A single- or dual-ring permeameter may be used in the tests. A dual-ring permeameter may be preferred over a single-ring permeameter to take into account and prevent short-circuiting of permeant along the sidewalls of the permeameter. The effects of sidewall flow is more significant at high stresses and when the cell diameter is less than 6 times the particle size ( 1 ) . 1.3 The test method is used under constant head conditions. 1.4 Water is used as the permeant with the test method. 1.5 Test Method D2434 also can be used for determination of hydraulic conductivity of materials derived from scrap tires with sizes smaller than 19 mm under constant head conditions in a rigid-wall permeameter. Method D2434 includes the use of a permeameter with a single ring. 1.6 The values stated in SI units are to be regarded as the standard. Hydraulic conductivity has traditionally been expressed in cm/s in the US, even though the official SI unit for hydraulic conductivity is m/s. 1.7 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. 1.8 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. ====== Significance And Use ====== 4.1 This test method is used to measure one-dimensional vertical flow of water through initially saturated samples of materials derived from scrap tires under an applied hydraulic gradient. Hydraulic conductivity is required in various civil engineering applications of scrap tires. 4.2 Samples are to be tested at a unit weight and under an overburden pressure representative of field conditions. Data from the literature indicate a reduction in hydraulic conductivity with increasing vertical pressure ( 1 ) . 4.3 Use of a dual-ring permeameter is included in this test method in addition to a single-ring permeameter. The dual-ring permeameter allows for minimizing potential adverse effects of sidewall leakage on measured hydraulic conductivity of the test specimens. The use of a bottom plate with an inner ring with a diameter smaller than the diameter of the permeameter and two outflow ports (one from the inner ring, one from the annular space between the inner ring and the permeameter) allows for separating the flow from the central part of the test specimen from the flow near the sidewall of the permeameter. 4.4 Darcy's law is assumed to be valid, flow is assumed to be laminar (Reynolds number less than approximately 2000–3000), and the hydraulic conductivity is assumed to be essentially independent of hydraulic gradient. The validity of Darcy's law may be evaluated by measuring the hydraulic conductivity of a specimen at three hydraulic gradients. The discharge velocity ( v = k × i ) is plotted against the applied hydraulic gradient. If the resulting relationship is linear and the measured hydraulic conductivity values are similar (i.e., within 25 %), then Darcy’s law may be taken as valid. Note 1: The quality of the result produced by this standard is dependent of the competence of the personnel using this standard and the suitability of the equipment and facilities. 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 these factors.