1、Standard Practice for Dry Preparation of Disturbed Soil and Soil-Aggregate Samples for Test AASHTO Designation: R 58-11 (2015)1American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1a R 58-1 AASHTO Standard Practice for
2、Dry Preparation of Disturbed Soil and Soil-Aggregate Samples for Test AASHTO Designation: R 58-11 (2015)11. SCOPE 1.1. This method describes the dry preparation of soil and soil-aggregate samples, as received from the field, for mechanical analysis, physical tests, and other tests as may be desired.
3、 1.2. The values stated in SI units are to be regarded as the standard. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 92, Wire-Cloth Sieves for Testing Purposes M 231, Weighing Devices Used in the Testing of Materials T 88, Particle Size Analysis of Soils T 89, Determining the Liquid Limit of Soi
4、ls T 90, Determining the Plastic Limit and Plasticity Index of Soils T 100, Specific Gravity of Soils T 248, Reducing Samples of Aggregate to Testing Size 3. APPARATUS 3.1. The balance shall conform to the requirements of M 231, for the class of general purpose balance required for the principal sam
5、ple mass of the sample being tested. 3.2. Drying ApparatusAny suitable device capable of drying samples at a temperature not exceeding 60C 140F. 3.3. SievesA series of sieves of the following sizes: 4.75 mm (No. 4), 2.00 mm (No. 10), 0.425 mm (No. 40), and others as required for preparing the sample
6、 for a specific test. The sieves shall conform to M 92. 3.4. Pulverizing ApparatusEither a mortar and rubber-covered pestle or a mechanical device consisting of a power-driven, rubber-covered muller suitable for breaking up the aggregations of soil particles without reducing the size of the individu
7、al grains. Note 1Other types of apparatus, such as a revolving drum into which the soil sample and rubber-covered rollers are placed and tumbled until soil aggregations are pulverized, are satisfactory if the aggregations of soil particles are broken up without reducing the size of the individual gr
8、ains. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a R 58-2 AASHTO 3.5. Sample SplitterA suitable riffle sampler or sample splitter for proportional splitting of the sample and capable of obtainin
9、g representative portions of the sample without appreciable loss of fines. The width of the container used to feed the riffle sample splitter should be equal to the total combined width of the riffle chutes. Proportional splitting of the sample on a canvas cloth is also permitted. Note 2The procedur
10、e for proportional splitting is described in T 248. 4. SAMPLE SIZE 4.1. The amounts of soil material required to perform the individual tests are as follows: 4.1.1. Particle Size Analysis of Soils (T 88)For the particle size analysis, material passing a 2.00-mm (No. 10) sieve is required in amounts
11、equal to approximately 110 g for sandy soils and approximately 60 g for silty or clayey soils. A sufficient amount of material retained on either the 4.75-mm (No. 4) sieve or 2.00-mm (No. 10) sieve is required (Note 3) to obtain a representative gradation, and, depending on the maximum particle size
12、, shall not be less than the amount shown in the following table: Diameter of Largest Particle, mm (in.) Approximate Minimum Mass of Portion, kg 9.5 (3/8) 0.5 25 (1) 2.0 50 (2) 4.0 75 (3) 5.0 Note 3The material for coarse sieve analysis may be separated by either of two alternate methods, Section 5.
13、2.1 (2.00-mm sieve) or Section 5.2.2 (4.75-mm sieve). When only a small percentage of the material will be retained on the 4.75-mm or 2.00-mm sieve, a considerable total mass of sample will be required to provide the minimum quantity shown in the above table; consequently, adherence to the minimum m
14、ass requirements in the above table may not be necessary if the material represented by the sample is not to be used in a base or subbase course, select borrow, or other item having a requirement for coarse aggregate. 4.1.2. Specific Gravity (T 100)For the specific gravity test performed in conjunct
15、ion with T 88, material passing the 2.00-mm (No. 10) sieve is required in the amounts (oven-dry) of at least 25 g when the volumetric flask is used and at least 10 g when the stoppered bottle is used. 4.1.3. Physical TestsFor the physical tests, material passing the 0.425-mm (No. 40) sieve is requir
16、ed in the total amount of at least 300 g, allocated approximately as follows: Test (and AASHTO Designation) Approximate Mass, g Liquid limit (T 89) 100 Plastic limit (T 90) 20 Shrinkage factors 30 Field moisture equivalent 50 Check and referee tests 100 5. INITIAL PREPARATION OF TEST SAMPLES 5.1. Dr
17、y the soil sample as received from the field thoroughly in air or in the drying apparatus at a temperature not exceeding 60C 140F. Obtain a representative test sample of the amount 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a vi
18、olation of applicable law.TS-1a R 58-3 AASHTO required to perform the desired tests (Section 4) with the sampler, or by splitting or quartering. Break up the aggregations of soil particles in the pulverizing apparatus in such a way as to avoid reducing the natural size of individual particles. Note
19、4Samples dried in an oven or other drying apparatus at a temperature not exceeding 60C 140F are considered to be air dried. 5.2. Weigh the portion of the dried sample selected for particle-sized analysis and physical tests (including specific gravity), and record that mass as the mass of total sampl
20、e uncorrected for hygroscopic moisture. Separate this portion into fractions by one of the following methods: 5.2.1. Alternate Methods Using 2.00-mm (No. 10) SieveSeparate the dried sample into two fractions using a 2.00-mm sieve. Grind the fraction retained on the sieve with the pulverizing apparat
21、us until the aggregations of soil particles are broken into separate grains. Separate the ground soil into two fractions using the 2.00-mm sieve. 5.2.2. Alternate Method Using 4.75-mm and 2.00-mm (Nos. 4 and 10) SievesSeparate the dried sample into two fractions using a 4.75-mm sieve. Grind the frac
22、tion retained on this sieve with the pulverizing apparatus until the aggregation of soil particles is broken into separate grains, and then separate these grains on the 4.75-mm sieve. Thoroughly mix the fractions passing the 4.75-mm sieve and, by the use of the sampler or by splitting and quartering
23、, obtain a representative portion adequate for the desired tests. Separate this portion on the 2.00-mm sieve and process it as described in Section 5.2.1. Record the mass of the material from this split-off fraction that is retained on the 2.00-mm sieve for later use in coarse sieve analysis computa
24、tions. 6. TEST SAMPLE FOR PARTICLE SIZE ANALYSIS AND SPECIFIC GRAVITY 6.1. Set aside the fraction retained on the 2.00-mm (No. 10) sieve in Section 5.2.1, or that retained on the 4.75-mm (No. 4) sieve in Section 5.2.2 after the second sieving, for use in sieve analysis of the coarse material. 6.2. T
25、horoughly mix the fractions passing the 2.00-mm (No. 10) sieve in both sieving operations in Sections 5.2.1 or 5.2.2 and, by the use of the sampler or by splitting or quartering, obtain representative portions having approximate masses as follows: (1) for the hydrometer analysis and sieve analysis o
26、f the fraction passing the 2.00-mm sieve, 110 g for sandy soil and 60 g for silty or clayey soils; and (2) for specific gravity, 25 g when the volumetric flask is to be used and 10 g when the stoppered bottle is to be used. 7. TEST SAMPLE FOR PHYSICAL TESTS 7.1. Separate the remaining portion of the
27、 material passing the 2.00-mm (No. 10) sieve into two parts by means of a 0.425-mm (No. 40) sieve. Grind the fraction retained on the 0.425-mm (No. 40) sieve with the pulverizing apparatus in such a manner as to break up the aggregations without fracturing the individual grains. If the sample contai
28、ns brittle particles, such as flakes of mica, fragments of sea shells, etc., carefully perform the pulverizing operation with just enough pressure to free the finer material that adheres to the coarser particles. Separate the ground soil into two fractions by means of the 0.425-mm (No. 40) sieve, an
29、d regrind the material retained on the sieve. When repeated grinding produces only a small quantity of soil passing the 0.425-mm sieve, discard the material retained on the 0.425-mm sieve. Thoroughly mix the several fractions passing the 0.425-mm sieve obtained from the grinding and sieving operations and set aside for use in performing the physical tests. 1Formerly T 87. Reclassified as a standard practice in 2011. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
