2. Getting involved
3. Standards Committees
4. NAW

DIN Standards Committee Water Practice

Overview

This International Standard specifies the treatments for the measurement of the stability of soil aggregates. It can be applied to a wide range of materials originating mainly from the tilled horizons of cultivated soils. It can, however, also apply to any soil profile horizon, whether it is cultivated or not. Aggregates ranging from 3 mm to 5 mm are measured. However, the presence of gravel in the 2 mm to 5 mm fraction can distort the results. If the percentage of gravel is between 10 % and 40 %, the > 2 mm fraction of the gravel obtained from the tests should be washed and a mean weighted diameter (MWD, see 6.1) calculated with and without gravel. If the percentage of gravel is > 40 %, the structural stability tests are not significant. The method does not apply to unstructured materials, as they are not sufficiently cohesive to form millimetric aggregates. The aim of the set of three treatments specified in this International Standard is to provide a means of predicting the behaviour of soil, with respect to its structural stability, for different conditions of soil wetting by water, which simulate different climatic, hydraulic and mechanical conditions that might be encountered in the field. It is therefore recommended that the three treatments be used in order to provide scientific information on the different mechanisms which can destroy soil aggregates. However, the use of the fast wetting test only, which is less time-consuming, can prove sufficient for a simple sample comparison. The treatments were chosen for the following purposes: - to distinguish between the various mechanisms; - to distinguish between the disaggregation phase and the measurement of the result of the disaggregation; - to express the results in a form that can be easily interpreted by comparison with physical soil behaviour in situ. The use of ethyl alcohol to ensure that disaggregation is well controlled on the one hand and, on the other hand, to limit the reaggregation of the particles on drying. The text of ISO 22155:2011 has been prepared by Technical Committee ISO/TC 190 "Soil quality" and has been taken over as EN ISO 22155:2013 by Technical Committee CEN/TC 345 "Characterization of soils", the secretariat of which is held by NEN. The responsible German body is Subcommittee NA 119-01-02-02 UA "Chemische und physikalische Verfahren" ("Chemical and physical processes") of Working Committee NA 119-01-02 AA "Abfall- und Bodenuntersuchungen" ("Examination of waste and soil") at the Water Practice Standards Committee (NAW) at DIN. NA 119-01-02 AA "Abfall- und Bodenuntersuchungen" ("Examination of waste and soil") voted against the adoption of International Standard ISO 10930 as a European Standard because the three different treatment methods specified in the standard result in different MWD values that cannot be compared with one another. However, these values are combined in Table 1 and interpreted together, which could easily lead to an incorrect interpretation. Because the majority of CEN/TC 345 members nevertheless voted to adopt this standard, DIN is obligated to publish it as a DIN EN Standard.

Document: references other documents

Responsible national committee

NA 119-01-02-02-09 AK - Physical methods  

Responsible european committee

CEN/TC 444/WG 5 - Physical tests  

Responsible international committee

ISO/TC 190/SC 3/WG 14 - Physical methods