1、Standard Method of Test for Grain-Size Analysis of Granular Soil Materials AASHTO Designation: T 311-00 (2015) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1a T 311-1 AASHTO Standard Method of Test for Grain-Siz
2、e Analysis of Granular Soil Materials AASHTO Designation: T 311-00 (2015) 1. SCOPE 1.1. This method covers the determination of the particle size distribution of granular soil material. This method utilizes the 6.3-mm sieve size for separation purposes. However, the sample tester may use an alternat
3、ive sieve size (i.e., 4.75 mm, 2.00 mm). In this case, the alternative sieve size used must replace the 6.3-mm size throughout this procedure. 1.2. Specifications for granular soil material, which reference this method, usually contain grading requirements that include both coarse and fine fractions
4、 in sizes between 100 mm and 0.075 mm. 1.3. The standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult and establish appropriat
5、e safety and health practices and determine the applicability of regulatory limitations prior to use. 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 2, Sampling of Aggregates 2.2. ASTM Standard: E
6、29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications 3. SUMMARY OF METHOD 3.1. A weighed sample of dry granular soil material is separated through a series of sieves with progressively smaller openings. Particle size distribution is determined
7、by weighing the material retained on each of the sieves and dividing these weights by the total dry weight of the sample. This method requires drying, washing, and a series of separations. 4. SIGNIFICANCE AND USE 4.1. This method is used primarily to determine the gradation of granular soil material
8、 for use as fill material in subbase, pipe, or structural backfill. Granular soil material used in these applications generally necessitates a well graded material. This results in samples that contain material that is retained on a wide range of sieve sizes. The results are used to determine the co
9、mpliance of grain size distribution of granular soil material with applicable specification requirements, and to 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 311-2 AASHTO provide the necessary
10、 data in order to determine the acceptability of this select granular material for the stated uses. This procedure is intended for use in quality assurance testing where large numbers of samples are processed. 5. APPARATUS 5.1. Platform ScaleThe platform scale shall conform to the requirements of M
11、231 for the class of general-purpose scale required for the principal sample weight being tested. 5.2. BalanceThe balance shall conform to the requirements of M 231 for the class of general-purpose balance required for the sample weight of fine granular material being tested. 5.3. SievesThe sieves s
12、hall be mounted on substantial frames constructed in a manner that will prevent loss of material during sieving. Suitable sieve sizes shall be selected to furnish the information required by the specifications covering the material to be tested. The sieves shall conform to M 92 (Note 1). Note 1It is
13、 recommended that sieves mounted in frames larger than standard 203-mm-diameter frames be used for testing coarse aggregate. Also, it may be desirable to use a heavy-duty screen meeting the required opening tolerances but with a larger wire diameter. 5.4. Mechanical Sieve ShakerA mechanical sieve sh
14、aker, if used, shall impact a vertical or lateral and vertical motion to the sieve, causing the particles thereon to bounce and turn so as to present different orientations to the sieving surface. The sieving action shall be such that the criterion for adequacy of sieving described in Section 7.4 is
15、 met in a reasonable time period. Note 2Use of a mechanical sieve shaker is recommended when the size of the sample is 20 kg or greater, and may be used for smaller samples, including fine granular material. Excessive time (more than approximately 5 min) to achieve adequate sieving may result in deg
16、radation of the sample. The same mechanical sieve shaker may not be practical for all sizes of samples, since the large sieving area needed for practical sieving of a large nominal size coarse granular material very likely could result in loss of a portion of the sample if used for a smaller sample
17、of coarse granular or fine granular material. 5.5. OvenAn oven of appropriate size capable of maintaining a uniform temperature of 110 5C. 5.6. MiscellaneousSpoons, spatulas, brushes, and containers (noncorroding and not subject to weight change). 6. SAMPLING AND PREPARATION 6.1. Sample the aggregat
18、e in accordance with T 2. 6.2. Sample Size: 6.2.1. For granular construction items, the sample(s) shall be transported to the testing facility in a clean, approved container. Assure that the sample size meets a minimum mass requirement of 20 kg. 2015 by the American Association of State Highway and
19、Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 311-3 AASHTO 6.2.2. For materials other than granular construction items, i.e., design testing, the sample(s) shall be transported to the testing facility in a clean, approved container and be large en
20、ough to be representative of the material being tested. In general, the larger the nominal maximum particle size is, the larger the sample should be in order to be considered representative. The following may be considered a guide (not a requirement) for sample masses on particle size: Nominal Maxim
21、um Particle Size Sample Mass 50 mm 20 kg 19 mm 7 kg 6.3 mm 1 kg 7. PROCEDURE Note 3Due to ease of operation, the following Procedure, Calculation, and Sieve Analysis Data Sheet utilizes a 6.3-mm sieve for separation. Depending on the sample type and size, or the testers preference, or both, alternat
22、ive sieve sizes can be used for separation (i.e., 4.75 mm, 2.00 mm). When an alternative sieve size is used, then that size must replace the 6.3-mm size as outlined in this method. In addition, a new Sieve Analysis Data Sheet must be developed for the alternative sieve size utilized. 7.1. Screen the
23、 sample on a 6.3-mm sieve in order to divide it into plus 6.3-mm and minus 6.3-mm portions. If an excessive amount of silt or clay adheres to the plus 6.3-mm material, it should be screened again after additional drying. If the sample does not have any plus 6.3-mm particles, proceed in accordance wi
24、th Section 7.4. Note 4During this initial and subsequent sieving, care should be exercised to prevent “overloading” the 6.3 mm and any other sieve. This condition exists when an excessive amount of soil is placed on the sieve, leaving an insufficient amount of sieve openings for the material to pass
25、 through. To avoid overloading, the sample must be divided into smaller portions and sieved separately. Note 5In some soils a significant amount of the particles will adhere together and form silt or clay balls, or both, that may be mistaken for plus 6.3-mm particles. Care must be taken to ensure th
26、at such balls pass through the 6.3-mm screen. It may be necessary to run a wood mallet over the material on the screen for this purpose; but be careful not to pulverize the actual particles or damage the sieve. 7.2. Once the plus 6.3-mm portion has fully dried (to the point where there is no visible
27、 sign of moisture), weigh the sample to the nearest 5 g and record this value (line A). Note 6Prior to weighing the plus 6.3-mm portion, check for particles larger than 100 mm. Remove such material and weigh it to the nearest 5 g and make a note of it on the data sheet. These particles should not be
28、 included in the test. (See Figures 1 and 2.) 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 311-4 AASHTO Project PROJECT STAMP PIN Contract No. Region County Material Source Location Offset Dep
29、th Item No. Sample No. LINE SAMPLE WEIGHTS LINE MOISTURE CONTENT A Wt. of Dry Plus 6.3 mm After Separation g G Container Number B Wt. of “Pan” Material from Plus 6.3 mm g H Wt. of Sample & Container Before Drying g C Wt. of Dry Plus 6.3 mm Material (A B) g I Wt. of Sample & Container After Drying g
30、D Wt. of Moist Minus 6.3 mm Material g J Wt. of Container g E Wt. of Dry Minus 6.3 mm D / (1 + (M / 100) g K Wt. of Water (H I) g F Wt. of Total Dry Sample (C + E) g L Wt. of Dry Sample (I J) g M Moisture Content (K / L) 100 SIEVE DESIGNATION 1 2 3 4 SPECIFICATION REQUIREMENT WEIGHT RETAINED % RETAI
31、NED % OF TOTAL SAMPLE PASSING WHOLE NO. % PASSING mm in. 100 4 75 3 50 2 37.5 11/225.0 1 19.0 3/412.5 1/29.5 3/86.3 1/4TOTAL N. Wt. of Dry Minus 6.3 mm Before Wash g O. Wt. of Dry Minus 6.3 mm After Wash g SIEVE DESIGNATION 5 6 7 8 9 SPECIFICATION REQUIREMENT WEIGHT RETAINED % RETAINED % PASSING BAS
32、ED ON MINUS 6.3 mm % OF TOTAL SAMPLE PASSING WHOLE NO. % PASSING mm No. 4.75 4 2.00 10 0.850 20 0.425 40 0.250 60 0.150 100 0.075 200 PAN TOTAL REMARKS TESTED BY: DATE: CHECKED BY: DATE: Figure 1Sieve Analysis Data Sheet 2015 by the American Association of State Highway and Transportation Officials.
33、All rights reserved. Duplication is a violation of applicable law.TS-1a T 311-5 AASHTO Project PROJECT STAMP PIN Contract No. Region County Material Source Location Offset Depth Item No. Sample No. LINE SAMPLE WEIGHTS LINE MOISTURE CONTENT A Wt. of Dry Plus 6.3 mm After Separation g 11340 G Containe
34、r Number AA B Wt. of “Pan” Material from Plus 6.3 mm g 10 H Wt. of Sample & Container Before Drying g 642.4 C Wt. of Dry Plus 6.3 mm Material (A B) g 11330 I Wt. of Sample & Container After Drying g 628.3 D Wt. of Moist Minus 6.3 mm Material g 13605 J Wt. of Container g 89.1 E Wt. of Dry Minus 6.3 m
35、m D / (1 + (M / 100) g 13260 K Wt. of Water (H I) g 14.1 F Wt. of Total Dry Sample (C + E) g 24590 L Wt. of Dry Sample (I J) g 539.2 M Moisture Content (K / L) 100 2.6 SIEVE DESIGNATION 1 2 3 4 SPECIFICATION REQUIREMENT WEIGHT RETAINED % RETAINED % OF TOTAL SAMPLE PASSING WHOLE NO. % PASSING mm in.
36、100 4 75 3 50 2 0 0.0 100.0 100 37.5 11/225.0 1 730 3.0 97.0 97 19.0 3/412.5 1/26100 24.8 72.2 72 9.5 3/86.3 1/44500 18.3 53.9 54 TOTAL 11330 46.1 N. Wt. of Dry Minus 6.3 mm Before Wash 301.4 g O. Wt. of Dry Minus 6.3 mm After Wash 280.2 g SIEVE DESIGNATION 5 6 7 8 9 SPECIFICATION REQUIREMENT WEIGHT
37、 RETAINED % RETAINED % PASSING BASED ON MINUS 6.3 mm % OF TOTAL SAMPLE PASSING WHOLE NO. % PASSING mm No. 4.75 4 2.00 10 67.6 22.4 77.6 41.8 42 0.850 20 0.425 40 161.1 53.4 24.2 13.0 13 0.250 60 0.150 100 26.4 8.8 15.4 8.3 8 0.075 200 24.8 8.2 7.2 3.9 4 PAN 0.3 TOTAL 280.2 92.8 REMARKS TESTED BY: DA
38、TE: CHECKED BY: DATE: Figure 2Sample Completed Sieve Analysis Data Sheet 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 311-6 AASHTO 7.3. Sieve the material retained on the 6.3-mm sieve during i
39、nitial separation of coarse and fine material. The series of sieves used shall comply with the particle size requirements of the material being tested. The sieves shall be arranged such that the largest opening sieve is on top, with the sizes progressively decreasing. The last sieve shall be the 6.3
40、 mm, followed by a “pan.” During the sieving process, some additional material will pass through the 6.3-mm sieve into the “pan.” Weigh this “pan” material to the nearest 5 g and record on line B of the data sheet. Incorporate this material to the minus 6.3-mm material obtained in Section 7.1. Weigh
41、 the material retained on each sieve to the nearest 5 g and record these values in Column 1 of the data sheet. Sum the values in Column 1 and record this value at the bottom of the column. Compute the total mass of plus 6.3-mm material by subtracting line B from line A, and record this value on line
42、 C. Note 7If the sieving is performed using a mechanical shaker, the sieves shall be shaken no less than 3 min and no more than 5 min. If performed manually, the sieve shall be shaken no less than 5 min. Very often particles will get stuck in the openings of a sieve. Such material shall be removed f
43、rom the openings and weighed as being retained on that sieve. Do not force particles through the sieves. 7.4. Weigh the portion of the minus 6.3-mm sample to the nearest 5 g and record this value on the data sheet (line D). Immediately mix the portion of minus 6.3-mm sample thoroughly. By quartering
44、 or using a sample splitter, obtain a minimum 500 g sample of this material, and place it into a container of known weight for a moisture content determination. The weight of the container and the weight of the soil and container should be recorded respectively to the nearest 0.1 g (lines J and H).
45、Dry the sample to a constant mass as noted below. After drying, allow the sample to cool and reweigh it to the nearest 0.1 g and record (line I). Note 8If the sample being tested is a recycled material, or if it contains any bituminous material (asphalt, etc.), it shall be dried to a constant weight
46、 by air-drying or in an oven not exceeding 60C. Note 9If a hot plate or stove is used, place the container holding the sample on a pan containing a thin layer of sand to prevent spattering and/or fracturing of the soil particles during the drying process. Note 10If an oven is used, maintain the temp
47、erature of the sample at 110 5C for a minimum of 12 h or until it maintains a constant weight. Note 11When a sample contains less than 500 g of minus 6.3-mm particles, moisture content and gradation may be performed on the smaller amount only if the sample is considered to be representative. 7.5. Ob
48、tain a 300 5 g portion of the moisture content sample (from Section 7.4) and record this mass to the nearest 0.1 g (line N). Wash this sample on a 0.075-mm sieve to remove all material finer than the 0.075-mm sieve from the sample. It is suggested to wash the sieve sample over a white basin to make
49、it easier to see when the wash water is clean. After the sample is thoroughly washed, carefully transfer the sample from the sieve to a container for drying. Dry the sample in accordance with the provisions of Section 7.4. Weigh the dried sample to the nearest 0.1 g and record this value (line O). Note 12Examine the 0.075-mm sieve prior to each washing to determine its condition. Replace the sieve if any holes or cracks are noticed in the solder or mesh, or if the sieves mesh is st
