ASTM D8281_D8281M-21 - Standard Test Method for Determining the Presence of Expanding Clays in Rock for Erosion Control Using Ethylene Glycol
Standard Test Method for Determining the Presence of Expanding Clays in Rock for Erosion Control Using Ethylene Glycol
| Standard number: | D8281_D8281M-21 |
| Released: | 01.05.2021 |
| Status: | Active |
| Pages: | 6 |
| Section: | 04.09 |
| Keywords: | armor stone; breakwater stone; climatic setting; erosion control; ethylene glycol; expanding clays; freeze-thaw; gabion-fill; jetty stone; laboratory testing; riprap; rock; rock material properties; Smectite; wet dry; |
1.1 This test method covers the testing for and quantitative determination of the presence of swelling clays of the smectite group in rock for erosion control. The test particles are intended to be representative of erosion control rock and its durability. The test is appropriate for breakwater stone, armor stone, riprap and gabion sized rock materials.
1.2 Ethylene glycol is one of the materials that react with swelling clays to form an organoclay complex having a larger basal spacing than that of the clay mineral itself. Rock containing swelling clay of the smectite group will be expected to undergo expansive breakdown upon soaking in ethylene glycol. If the amount, distribution, state of expansion, and ability to take up glycol is such as to cause such breakdown to occur, it may be expected that similar breakdown may occur of similar rock samples exposed, for longer times, to wetting and drying or freezing and thawing in a water-soaked condition in service.
1.3 The prepared size of the rock specimens may eliminate some of the internal features present in the gross structure. The test specimens may not be representative of the quality of the larger rock samples used in construction. Careful examination of the rock source and proper sampling are essential in minimizing this limitation.
1.3.1 The test is time intensive and requires over two weeks to complete the sample preparation, testing and analysis portions of the procedure.
1.4 The use of reclaimed concrete and materials other than natural rock is beyond the scope of this test method.
1.5 Units—The values stated in either SI units or inch-pound units 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 non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.
1.5.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The slug unit is not given unless dynamic (F=ma) calculations are involved.
1.5.2 The SI units presented for apparatus are substitutions of the inch-pound units, other similar SI units should be acceptable providing they meet the technical requirements established by the inch-pound apparatus.
1.5.3 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and force (lbf). This practice implicitly combines two separate systems of units: the absolute and the gravitational systems. 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 for mass. However, the use of balances or scales recording pounds of mass (lbm) or recording density in lbm/ft3 shall not be regarded as nonconformance with this standard.
1.5.4 Calculations are done using only one set of units; either SI or gravitational inch pound. Other units are permissible provided appropriate conversion factors are used to maintain consistency of units throughout the calculations, and similar significant digits or resolution, or both are maintained.
1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this standard.
1.6.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits.
1.6.2 The procedures used to specify how data are collected/recorded or calculated, in this 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 this standard to consider significant digits used in analytical methods for engineering design.
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.