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 rock particles are intended to be representative of erosion control rock and its weaknesses. The test is appropriate for the evaluation of 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 organo-clay 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 uptake glycol is such that it may cause this type of breakdown. If such breakdown does occur, similar breakdown may be anticipated if similar rock samples are exposed, for longer times, to wetting and drying or freezing and thawing in a water-soaked service condition. 1.3 The use of reclaimed concrete and other materials is beyond the scope of this test method. 1.4 Units-The values stated in either SI units or inch-pound units (presented 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. 1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this standard. 1.5.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded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. 1.5.2 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 users 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. 1.6 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 and health practices and determine the applicability of regulatory limitations prior to use.
Potentially deleterious clays can be found in rock for erosion control. The industry does not have a current procedure to determine the presence of such clays. To serve the erosion control industry, it is in ASTMs best interest to develop a standard test procedure to address this situation.
Keywordsarmor stone; breakwater stone; riprap; gabion-fill stone; climatic setting; erosion control; freeze-thaw; wet-dry; gabion-fill; laboratory testing; riprap; rock; expanding clays; smectite; montmorillonite; ethylene glycol; rock material properties
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
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