AASHTO T 27-2014 Standard Method of Test for Sieve Analysis of Fine and Coarse Aggregates.pdf

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1、Standard Method of Test for Sieve Analysis of Fine and Coarse Aggregates AASHTO Designation: T 27-141ASTM Designation: C136-06 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1c T 27-1 AASHTO Standard Method of Tes

2、t for Sieve Analysis of Fine and Coarse Aggregates AASHTO Designation: T 27-141ASTM Designation: C136-06 1. SCOPE 1.1. This method covers the determination of the particle size distribution of fine and coarse aggregates by sieving. 1.2. Some specifications for aggregates, which reference this method

3、, contain grading requirements including both coarse and fine fractions. Instructions are included for sieve analysis of such aggregates. 1.3. The values stated in SI units are to be regarded as the standard. The values in parentheses are provided for information purposes only. 1.4. This standard ma

4、y 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 appropriate safety and health practices and determine the applicabili

5、ty of regulatory regulations 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 T 11, Materials Finer Than 75-m (No. 200) Sieve in Mineral Aggregates by Washing

6、 T 248, Reducing Samples of Aggregate to Testing Size 2.2. ASTM Standards: C125, Standard Terminology Relating to Concrete and Concrete Aggregates C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials 2.3. IEEE/ASTM Standard: SI10, American N

7、ational Standard for Metric Practice 3. TERMINOLOGY 3.1. DefinitionsFor definitions of terms used in this standard, refer to ASTM C125. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 27-2 AASHTO

8、 4. SUMMARY OF METHOD 4.1. A sample of dry aggregate of known mass is separated through a series of sieves of progressively smaller openings for determination of particle size distribution. 5. SIGNIFICANCE AND USE 5.1. This method is used primarily to determine the grading of materials proposed for

9、use as aggregates or being used as aggregates. The results are used to determine compliance of the particle size distribution with applicable specification requirements and to provide necessary data for control of the production of various aggregate products and mixtures containing aggregates. The d

10、ata may also be useful in developing relationships concerning porosity and packing. 5.2. Accurate determination of material finer than the 75-m (No. 200) sieve cannot be achieved by use of this method alone. Test Method T 11 for material finer than the 75-m (No. 200) sieve by washing should be emplo

11、yed. 6. APPARATUS 6.1. BalanceThe balance shall have sufficient capacity, be readable to 0.1 percent of the sample mass, or better, and conform to the requirements of M 231. 6.2. SievesThe sieve cloth shall be mounted on substantial frames constructed in a manner that will prevent loss of material d

12、uring sieving. The sieve cloth and standard sieve frames shall conform to the requirements of M 92. Nonstandard sieve frames shall conform to the requirements of M 92 as applicable. Note 1It is recommended that sieves mounted in frames larger than standard 203.2 mm (8 in.) diameter be used for testi

13、ng coarse aggregate to reduce the possibility of overloading the sieves. See Section 8.3. 6.3. Mechanical Sieve ShakerA mechanical sieving device, if used, shall create motion of the sieves to cause the particles to bounce, tumble, or otherwise turn so as to present different orientations to the sie

14、ving surface. The sieving action shall be such that the criterion for adequacy of sieving described in Section 8.4 is met in a reasonable time period. Note 2Use of a mechanical sieve shaker is recommended when the size of the sample is 20 kg (44 lb) or greater, and may be used for smaller samples, i

15、ncluding fine aggregate. Excessive time (more than approximately 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 the large sieving area needed for practical sieving of a large nominal

16、size coarse aggregate very likely could result in loss of a portion of the sample if used for a smaller sample of coarse aggregate or fine aggregate. 6.4. OvenAn oven of appropriate size capable of maintaining a uniform temperature of 110 5C (230 9F). 7. SAMPLING 7.1. Sample the aggregate in accorda

17、nce with T 2. The mass of the field sample shall be the mass shown in T 2 or four times the mass required in Sections 7.4 and 7.5 (except as modified in Section 7.6), whichever is greater. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication

18、 is a violation of applicable law.TS-1c T 27-3 AASHTO 7.2. Thoroughly mix the sample and reduce it to an amount suitable for testing using the applicable procedures described in T 248. The sample for test shall be the approximate mass desired when dry and shall be the end result of the reduction. Re

19、duction to an exact predetermined mass shall not be permitted. Note 3Where sieve analysis, including determination of material finer than the 75-m (No. 200) sieve, is the only testing proposed, the size of the sample may be reduced in the field to avoid shipping excessive quantities of extra materia

20、l to the laboratory. 7.3. Fine AggregateThe size of the test sample of aggregate, after drying, shall be 300 g minimum. 7.4. Coarse AggregateThe mass of the test sample of coarse aggregate shall conform with the following: Nominal Maximum Size Square Openings, mm (in.) Minimum Mass of Test Sample, k

21、g (lb) 9.5 (3/8) 1 (2) 12.5 (1/2) 2 (4) 19.0 (3/4) 5 (11) 25.0 (1) 10 (22) 37.5 (11/2) 15 (33) 50 (2) 20 (44) 63 (21/2) 35 (77) 75 (3) 60 (130) 90 (31/2) 100 (220) 100 (4) 150 (330) 125 (5) 300 (660) 7.5. Coarse and Fine Aggregates MixturesThe mass of the test sample of coarse and fine aggregate mix

22、tures shall be the same as for coarse aggregate in Section 7.4. 7.6. Samples of Large-Size Coarse AggregateThe size of sample required for aggregate with 50-mm (2-in.) nominal maximum size or larger is such as to preclude convenient sample reduction and testing as a unit except with large mechanical

23、 splitters and sieve shakers. As an option when such equipment is not available, instead of combining and mixing sample increments and then reducing the field sample to testing size, conduct the sieve analysis on a number of approximately equal sample increments such that the total mass tested confo

24、rms to the requirements of Section 7.4. 7.7. In the event that the amount of material finer than the 75-m (No. 200) sieve is to be determined by T 11, use the procedure described in Section 7.7.1 or 7.7.2, whichever is applicable. 7.7.1. For aggregates with a nominal maximum size of 12.5 mm (1/2in.)

25、 or less, use the same test sample for testing by T 11 and this method. First test the sample in accordance with T 11 through the final drying operation, then dry sieve the sample as stipulated in Sections 8.2 through 8.6 of this method. 7.7.2. For aggregates with a nominal maximum size greater than

26、 12.5 mm (1/2in.), a single test sample may be used as described in Section 7.7.1 or separate test samples may be used for T 11 and this method. 7.7.3. Where the specification requires determination of the total amount of material finer than the 75-m (No. 200) sieve by washing and dry sieving, use t

27、he procedure described in Section 7.7.1. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 27-4 AASHTO 8. PROCEDURE 8.1. If the test sample has not been subjected to testing by T 11, dry it to cons

28、tant mass at a temperature of 110 5C (230 9F). Determine and record the mass of material that will be placed on the sieves to the accuracy of the balance as defined in Section 6.1. Note 4For control purposes, particularly where rapid results are desired, it is generally not necessary to dry coarse a

29、ggregate for the sieve analysis test. The results are little affected by the moisture content unless (1) the nominal maximum size is smaller than about 12.5 mm (1/2in.), (2) the coarse aggregate contains appreciable material finer than 4.75 mm (No. 4), or (3) the coarse aggregate is highly absorptiv

30、e (a lightweight aggregate, for example). Also, samples may be dried at the higher temperature associated with the use of hot plates without affecting results, provided steam escapes without generating pressures sufficient to fracture the particles, and temperatures are not so great as to cause chem

31、ical breakdown of the aggregate. 8.2. Select sieves with suitable openings to furnish the information required by the specifications covering the material to be tested. Use additional sieves as desired or necessary to provide other information, such as fineness modulus, or to regulate the amount of

32、material on a sieve. Nest the sieves in order of decreasing size of opening from top to bottom and place the sample, or portion of the sample if it is to be sieved in more than one increment, on the top sieve. Agitate the sieves by hand or by mechanical apparatus for a sufficient period, established

33、 by trial or checked by measurement on the actual test sample, to meet the criterion for adequacy of sieving described in Section 8.4. 8.3. Limit the quantity of material on a given sieve so that all particles have opportunity to reach sieve openings a number of times during the sieving operation. F

34、or sieves with openings smaller than 4.75-mm (No. 4), the quantity retained on any sieve at the completion of the sieving operation shall not exceed 7 kg/m2(4 g/in.2) of sieving surface area (Note 5). For sieves with openings 4.75 mm (No. 4) and larger, the quantity retained in kg shall not exceed t

35、he product of 2.5 (sieve opening, mm (effective sieving area, m2). This quantity is shown in Table 1 for five sieve-frame dimensions in common use. In no case shall the quantity retained be so great as to cause permanent deformation of the sieve cloth. 8.3.1. Prevent an overload of material on an in

36、dividual sieve by one or a combination of the following methods: 8.3.1.1. Insert an additional sieve with opening size intermediate between the sieve that may be overloaded and the sieve immediately above that sieve in the original set of sieves. 8.3.1.2. Split the sample into two or more portions,

37、sieving each portion individually. Combine the masses of the several portions retained on a specific sieve before calculating the percentage of the sample on the sieve. 8.3.1.3. Use sieves having a larger frame size and providing greater sieving area. Note 5The 7 kg/m2amounts to 200 g for the usual

38、203.2-mm (8-in.) diameter sieve (with effective sieving surface diameter of 190.5 mm (7.5 in.). 8.3.1.4. In the case of coarse and fine aggregate mixtures, the portion of the sample finer than the 4.75-mm (No. 4) sieve may be distributed among two or more sets of sieves to prevent overloading of ind

39、ividual sieves. 8.3.1.5. Alternatively, the portion finer than the 4.75-mm (No. 4) sieve may be reduced in size using a mechanical splitter according to T 248. If this procedure is followed, compute the mass of each size increment of the original sample as follows: 2015 by the American Association o

40、f State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 27-5 AASHTO 12WABW= (1) where: A = mass of size increment on total sample basis, W1= mass of fraction finer than 4.75-mm (No. 4) sieve in total sample, W2= mass of reduced portion o

41、f material finer than 4.75-mm (No. 4) sieve actually sieved, and B = mass of size increment in reduced portion sieved. Table 1Maximum Allowable Quantity 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 58

42、0, mm Sieving Area, m20.0285 0.0457 0.0670 0.1225 0.2158 125 mm (5 in.) c c c c 67.4 100 mm (4 in.) c c c 30.6 53.9 90 mm (3 1/2in.) c c 15.1 27.6 48.5 75 mm (3 in.) c 8.6 12.6 23.0 40.5 63 mm (2 1/2in.) 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 (1 1/2in.) 2.7 4.3 6.3 11.5 20.

43、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 10.2 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 i

44、n. (14 by 14 in. nominal); 14.6 by 22.8 in. (16 by 24 in. nominal). bThe sieve area for round sieves is based on an effective diameter 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 siev

45、e cloth. Thus the effective sieving diameter for a 203.2-mm (8.0-in.) diameter sieve frame is 190.5 mm (7.5 in.). 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 siev

46、e testing. 8.4. Continue sieving for a sufficient period and in such manner that, after completion, not more than 0.5 percent by mass of the total sample passes any sieve during 1 min of continuous hand sieving performed as follows: Hold the individual sieve, provided with a snug-fitting pan and cov

47、er, in a slightly inclined position in one hand. Strike 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 minute, turn the sieve about one sixth of a revolution at intervals of about 25 strokes. In determining sufficiency of

48、 sieving for sizes larger than the 4.75-mm (No. 4) sieve, 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 203.2-mm (8-in.) diameter sieves to verify the sufficiency of sieving. 8.5. Unless a

49、 mechanical sieve shaker is used, hand sieve particles obtained on the 75 mm (3 in.) by determining the smallest sieve opening through which each particle will pass by rotating the particles, if necessary, in order to determine whether they will pass through a particular opening; however, do not force particles to pass through an opening. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 27-6 AASHTO 8.6. Determine the ma