1、Standard Method of Test for Mechanical Analysis of Extracted Aggregate AASHTO Designation: T 30-15 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2c T 30-1 AASHTO Standard Method of Test for Mechanical Analysis of
2、 Extracted Aggregate AASHTO Designation: T 30-15 1. SCOPE 1.1. This method covers a procedure for the determination of the particle-size distribution of fine and coarse aggregates extracted from asphalt mixtures using sieves with square openings. 1.2. The values stated in SI units are to be regarded
3、 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 R 18, Establishing and Implementing a Quality Management System for Construction Materials Testing Laboratories R 35, Superpave Volum
4、etric Design for Asphalt Mixtures R 61, Establishing Requirements for Equipment Calibrations, Standardizations, and Checks T 164, Quantitative Extraction of Asphalt Binder from Hot Mix Asphalt (HMA) T 255, Total Evaporable Moisture Content of Aggregate by Drying T 308, Determining the Asphalt Binder
5、 Content of Hot Mix Asphalt (HMA) by the Ignition Method 2.2. ASTM Standard: C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials 3. SIGNIFICANCE AND USE 3.1. This method is used to determine the grading of aggregates extracted from asphalt
6、mixtures. The results are used to determine compliance of the particle-size distribution with applicable requirements and to provide necessary data for control of the production of various aggregates to be used in asphalt mixtures. 4. APPARATUS 4.1. BalanceA Class G2 balance meeting the accuracy req
7、uirements of M 231. 4.2. SievesConforming to the requirements of M 92. 4.3. Mechanical Sieve ShakerA mechanical sieving device, if used, shall continually reorient the particles on the sieving surface. The sieving action shall meet the requirements for sieving adequacy described in Section 7 in a re
8、asonable time period (Note 1). 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c T 30-2 AASHTO Note 1Use of a mechanical sieve shaker is recommended when the size of the sample is 20 kg (44 lb) or gr
9、eater, and may be used for smaller samples, including fine aggregate. Excessive time (more than 10 min) to achieve adequate sieving may result in degradation of the sample. The same mechanical sieve shaker may not be practical for all sizes of samples, because a large sieving area is needed for prac
10、tical sieving of a large nominal size coarse aggregate. Use of the same device for a smaller size of coarse aggregate or fine aggregate will likely result in loss of a portion of the sample. 4.4. OvenAn oven of sufficient size, capable of maintaining a uniform temperature of 110 5C (230 9F). 4.5. We
11、tting AgentAny dispersing agent, such as dishwashing detergent, that will promote separation of the fine materials. 4.6. ContainerA pan or vessel of a size sufficient to contain the sample covered with water and to permit vigorous agitation without loss of any part of the sample or water. 4.7. Spoon
12、 or Mixing UtensilOr similar device for agitating the sample during the washing procedure. 4.8. Mechanical Washing Apparatus (Optional)A mechanical washing apparatus (Note 2). Note 2The use of some mechanical washing equipment with certain material types may cause degradation of the sample, impactin
13、g the results of the particle size analysis. To determine if a particular mechanical washing apparatus causes significant degradation, prepare a known aggregate blend gradation in the laboratory using washed and graded aggregate from individual aggregate stockpiles similarly to preparing an aggregat
14、e trial blend gradation specified in R 35. Mechanically wash and then grade the prepared aggregate blend sample. Compare the mechanically washed grading results to the known gradation of the laboratory-prepared aggregate blend for each sieve size. If the determined percentage passing each sieve for
15、mechanical washing differs by more than the acceptable range of two results between laboratories given in Table 2, the mechanical washing apparatus should not be used. 5. CALIBRATIONS, STANDARDIZATIONS, AND CHECKS 5.1. Unless otherwise specified, follow the requirements and intervals for equipment c
16、alibrations, standardizations, and checks found in R 18. 5.2. Follow the procedures for performing equipment calibration, standardizations, and checks found in R 61. 6. SAMPLE 6.1. The sample shall consist of the entire lot or representative sample of aggregate obtained according to T 164 or T 308 f
17、rom which the binder material has been extracted. 7. PROCEDURE 7.1. Dry the sample, if necessary, until further drying at 110 5C (230 9F) does not alter the mass by more than 0.1 percent (Note 3). Determine and record the mass of the sample to the nearest 0.1 g. Note 3Samples obtained from T 164 or
18、T 308 should be dried to constant mass as part of the procedures within those standards. If the procedures described herein are completed immediately 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c
19、 T 30-3 AASHTO following the procedures in either of those methods, it will not be necessary to dry the sample again. If more than 24 h pass between the completion of T 164 or T 308 and the beginning of this test procedure, if the sample is stored in a high-humidity environment, or has otherwise bee
20、n subjected to moisture, the sample should be dried again to constant mass. 7.1.1. If the sample consists of aggregate obtained from T 164, add the mass of mineral matter contained in the extracted asphalt binder to the mass of the dry sample and record this value as the initial specimen mass (Note
21、4). The procedure for determination of the mineral matter content of the extracted asphalt is described in T 164. Note 4If the asphalt mixture was extracted in accordance with T 164, Method E, for plant control purposes, a mineral matter determination may not have been completed. In this case, recor
22、d the mass determined in Section 7.1 as the initial specimen mass. 7.1.2. If the sample consists of aggregate obtained from T 308, the mass determined in Section 7.1 shall agree with the mass of aggregate remaining after ignition (Mffrom T 308) within 0.1 percent. If the variation exceeds 0.1 percen
23、t, the results of this test should not be used for acceptance purposes. Record the mass determined in Section 7.1 as the initial specimen mass. 7.2. Place the test sample in a container and cover it with water. Add a sufficient amount of wetting agent to assure a thorough separation of the material
24、finer than the 75-m (No. 200) sieve from the coarser particles. Add the wetting agent (Note 5). Agitate the contents of the container vigorously and immediately decant the wash water over a nest of two sieves consisting of a 2.00-mm (No. 10) or 1.18-mm (No. 16) sieve superimposed on a 75-m (No. 200)
25、 sieve (Note 6). The use of a large spoon or similar device is recommended to aid the process of agitating the contents of the container. Limit agitation by mechanical washing equipment to a maximum of 10 min. Note 5There should be enough wetting agent to produce a small amount of suds when the samp
26、le is agitated. The quantity will depend on the hardness of the water, the quality of the detergent, and the agitation process. Excessive suds may overflow the sieves and carry some material with them. Note 6When mechanical washing equipment is used, the introduction of water, agitating, and decanti
27、ng may be a continuous operation. 7.3. Vigorously agitate the sample, bringing the particles finer than the 75-m (No. 200) sieve into suspension. Decant the suspension over the sieve nest in order to completely separate the fine particles from the coarse particles. Use care to avoid, as much as poss
28、ible, the decantation of the coarse particles of the sample onto the sieve nest. Repeat the operation until the wash water is clear. Do not overflow or overload the 75-m (No. 200) sieve. 7.4. Return all material retained on the nested sieves to the container. Dry the washed aggregate in the containe
29、r to constant mass in accordance with T 255 and determine its mass to the nearest 0.1 percent. 7.5. Sieve the aggregate over various sieve sizes, including the 75-m (No. 200) sieve as required by the specification covering the asphalt mixtures. Additional sieve sizes may be used to regulate the amou
30、nt of material on a sieve to meet the requirements of Section 7.6. Nest the sieves in order of decreasing size of opening from top to bottom and place the sample on the top sieve. Agitate the sieves by a mechanical apparatus for a sufficient period, established by trial or checked by measurement on
31、the actual test sample, to meet the criterion for adequacy of sieving described in Section 7.7. 7.6. Limit the quantity of material on a given sieve so that all particles have the opportunity to reach sieve openings a number of times during the sieving operation. Do not exceed a mass of 7 kg/m2(4 g/
32、in.2) retained per sieving surface on any sieve with openings smaller than 4.75 mm (No. 4) at the completion of the sieving operation (Note 7). Do not exceed a mass in kg of the product of 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication
33、 is a violation of applicable law.TS-2c T 30-4 AASHTO 2.5 (sieve opening in mm) (the effective or clear sieving surface area, m2) for sieves with openings 4.75 mm (No. 4) and larger. For sieves with openings 4.75 mm (No. 4) and larger, this mass is shown in Table 1 for five sieve-frame dimensions in
34、 common use. Do not cause permanent deformation of the sieve cloth due to overloading. Note 7The 7 kg/m2(4 g/in.2) amounts to 200 g for the usual 203-mm (8-in.) diameter sieve with effective or clear sieving surface diameter of 190.5 mm (71/2in.) or 450 g for a 305-mm (12-in.) diameter sieve with ef
35、fective or clear sieving surface diameter of 292.1 mm (111/2in.). The amount of material retained on a sieve may be regulated by: (1) the introduction of a sieve with larger openings immediately above the given sieve, (2) testing the sample in a number of increments, or (3) testing the sample over a
36、 nest of sieves with a larger sieve-frame dimension. Table 1Maximum Allowable Mass of Material Retained on a Sieve, kg Nominal Dimensions of SieveaSieve Opening Size 203.2-mm, diab254-mm, diab304.8-mm, diab350 by 350, mm 372 by 580, mm Sieving Area, m20.0285 0.0457 0.0670 0.1225 0.2158 125 mm (5 in.
37、) c c c c 67.4 100 mm (4 in.) c c c 30.6 53.9 90 mm (31/2in.) c c 15.1 27.6 48.5 75 mm (3 in.) c 8.6 12.6 23.0 40.5 63 mm (21/2in.) c 7.2 10.6 19.3 34.0 50 mm (2 in.) 3.6 5.7 8.4 15.3 27.0 37.5 mm (11/2in.) 2.7 4.3 6.3 11.5 20.2 25.0 mm (1 in.) 1.8 2.9 4.2 7.7 13.5 19.0 mm (3/4in.) 1.4 2.2 3.2 5.8 1
38、0.2 12.5 mm (1/2in.) 0.89 1.4 2.1 3.8 6.7 9.5 mm (3/8in.) 0.67 1.1 1.6 2.9 5.1 4.75 mm (No. 4) 0.33 0.54 0.80 1.5 2.6 aSieve-frame dimensions in inch units: 8.0-in. diameter; 10.0-in. diameter; 12.0-in. diameter; 13.8 by 13.8 in. (14 by 14 in. nominal); 14.6 by 22.8 in. (16 by 24 in. nominal). bThe
39、sieve area for round sieves is based on an effective or clear diameter of 12.7 mm (1/2in.) less than the nominal frame diameter, because M 92 permits the sealer between the sieve cloth and the frame to extend 6.35 mm (1/4in.) over the sieve cloth. Thus the effective or clear sieving diameter for a 2
40、03.2-mm (8.0-in.) diameter sieve frame is 190.5 mm (71/2in.). Sieves produced by some manufacturers do not infringe on the sieve cloth by the full 6.35 mm (1/4in.). cSieves indicated have less than five full openings and should not be used for sieve testing. 7.7. Continue sieving for a sufficient pe
41、riod and in such manner that, after completion, not more than 0.5 percent by mass of the total sample passes any sieve during 60 s of continuous hand-sieving performed as follows: Hold the individual sieve, provided with a snug-fitting pan and cover, in a slightly inclined position in one hand. Stri
42、ke the side of the sieve sharply and with an upward motion against the heel of the other hand at the rate of about 150 times per min, turning the sieve about one-sixth of a revolution at intervals of about 25 strokes. In determining the adequacy of sieving for sizes larger than the 4.75-mm (No. 4) s
43、ieve, limit the material on the sieve to a single layer of particles. If the size of the mounted testing sieves makes the described sieving motion impractical, use 203-mm (8-in.) diameter sieves to verify the adequacy of sieving. 8. CALCULATIONS 8.1. Record the mass of material passing each sieve, t
44、he mass retained on the next sieve, and the amount passing the 75-m (No. 200) sieve. The sum of these masses must be within 0.2 percent of the mass after washing. Add the mass of dry material passing the 75-m (No. 200) sieve by dry sieving to the mass removed by washing, and if applicable, the mass
45、of mineral matter in the asphalt binder, in order to obtain the total passing the 75-m (No. 200) sieve. Convert the masses 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c T 30-5 AASHTO of fractions
46、 retained on the various sieves and the total passing the 75-m (No. 200) sieve to percentages by dividing each by the initial specimen mass determined in Section 7.1.1 or 7.1.2, as applicable. 8.2. For aggregate samples obtained from T 308, apply the aggregate correction factor, as required in T 308
47、, to obtain the final total passing percentages. 9. REPORT 9.1. Report the results of the sieve analysis as follows: (a) total percentages passing each sieve; or (b) total percentages retained on each sieve; or (c) percentages retained between consecutive sieves, depending upon the form of the speci
48、fications of the material being tested. Report percentages to the nearest whole number, except for the percentage passing the 75-m (No. 200) sieve, which shall be reported to the nearest 0.1 percent. 10. PRECISION AND BIAS 10.1. PrecisionThe estimates of precision for this test method are listed in
49、Table 1. The estimates are based on the results from the AASHTO Materials Reference Laboratory Proficiency Sample Program, with testing conducted by T 30. The data are based on the analyses of the test results from 47 to 190 laboratories that tested 17 pairs of proficiency test samples (Samples No. 1 through 34). The values in the table are given for different ranges of total percentage of aggregate passing a sieve. Table 2Precision Total Percentage of Material Passing a Sieve Standard Deviation (1s) PercentaAccep
