1、Standard Method of Test for Lightweight Particles in Aggregate AASHTO Designation: T 113-18 Technical Section: 1c, Aggregates Release: Group 3 (August) ASTM Designation: C123/C123M-12 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washingt
2、on, D.C. 20001 TS-1c T 113-1 AASHTO Standard Method of Test for Lightweight Particles in Aggregate AASHTO Designation: T 113-18 Technical Section: 1c, Aggregates Release: Group 3 (August) ASTM Designation: C123/C123M-12 1. SCOPE 1.1. This method covers the determination of the percentage of lightwei
3、ght particles in aggregate by means of sinkfloat separation in a heavy liquid of suitable specific gravity. 1.2. The values stated in SI units are to be regarded as the standard. 1.3. This standard involves hazardous materials, operations, or equipment. This standard does not purport to address all
4、of the safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to its use. For a specific hazard statement, see Note 2. Use of chemicals mus
5、t conform to the requirements of 29 CFR 1910.1200. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 6, Fine Aggregate for Hydraulic Cement Concrete M 80, Coarse Aggregate for Hydraulic Cement Concrete M 231, Weighing Devices Used in the Testing of Materials R 76, Reducing Samples of Aggregate to Tes
6、ting Size R 90, Sampling Aggregate Products T 27, Sieve Analysis of Fine and Coarse Aggregates T 84, Specific Gravity and Absorption of Fine Aggregate T 85, Specific Gravity and Absorption of Coarse Aggregate 2.2. ASTM Standards: D3665, Standard Practice for Random Sampling of Construction Materials
7、 E11, Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves E100, Standard Specification for ASTM Hydrometers 2.3. Federal Standard: Fed. Std. No. 29, CFR 1910.1200 OSHA Hazard Communication Standard; see also Permissible Exposure LimitsAnnotated Tables, available at https:/www.osha
8、.gov/dsg/annotated-pels/ 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c T 113-2 AASHTO 3. SIGNIFICANCE AND USE 3.1. This method is used to determine conformance with provisions of M 6 and M 80 pe
9、rtaining to the amount of lightweight material in fine and coarse aggregates. A heavy liquid with a specific gravity of 2.0 is used to separate particles, which may be classified as coal or lignite. Heavier liquids are used to check the percentages of other lightweight particles, such as chert havin
10、g a specific gravity less than 2.40. Note 1The method is useful in identifying porous aggregate particles in research activities or in petrographic analyses. 4. APPARATUS 4.1. BalanceThe balance shall have sufficient capacity, be readable to 0.1 percent of the sample mass or better, and conform to t
11、he requirements of M 231. 4.2. ContainersSuitable for drying the aggregate sample, and containers suitable for holding the heavy liquid during the sinkfloat separation. 4.3. SkimmerA piece of 300-m (No. 50) sieve cloth, conforming to ASTM E11, of suitable size and shape for separating the floating p
12、articles from the heavy liquid. 4.4. Hot Plate or OvenOf appropriate size capable of maintaining a uniform temperature of 110 5C (230 9F). 4.5. Sieves300-m (No. 50) and 4.75-mm (No. 4) conforming to ASTM E11. 4.6. Specific Gravity MeasurementA hydrometer conforming to the physical requirement sectio
13、ns for individual hydrometers of ASTM E100 or a suitable combination of graduated glassware and balance, capable of measuring the liquid specific gravity within 0.01. 4.7. Mechanical Sieve ShakerConforming to the requirements of T 27. 5. HEAVY LIQUID 5.1. The heavy liquid shall be able to achieve th
14、e required specific gravity and be readily removable from the sample. The heavy liquid shall consist of one of the following: (See Note 2.) 5.1.1. A solution of zinc chloride in water (for materials having a specific gravity less than 2.0). 5.1.2. A solution of zinc bromide in water (for materials h
15、aving a specific gravity less than 2.6). Note 2Caution: There is no particular hazard from the fumes of zinc chloride solution (Section 5.1.1) or zinc bromide solution (Section 5.1.2), but goggles and gloves shall be worn to prevent contact with the eyes or skin. Use of a downdraft hood is recommend
16、ed, especially while mixing the working solution. 6. SAMPLE PREPARATION 6.1. Obtain a sample of the aggregate according to R 90 and ASTM D3665. Reduce the sample to test portion size according to R 76. 2018 by the American Association of State Highway and Transportation Officials. All rights reserve
17、d. Duplication is a violation of applicable law.TS-1c T 113-3 AASHTO Nominal Maximum Size of Aggregate (Square-Opening Sieves) Minimum Mass of Sample, g 4.75 mm (No. 4) 200 9.5 mm (3/8in.) 1500 19.0 mm (3/4in.) 3000 37.5 mm (11/2in.) 5000 75 mm (3 in.) 10000 If the nominal maximum size of the aggreg
18、ate to be tested is not listed above, the next largest size shall be used to determine the sample size. 6.2. Dry the test portion at a temperature of 110 5C (230 9F) until there is less than 0.1 percent loss after an additional 20 min of drying (constant mass). 6.3. Fine Aggregate: 6.3.1. Cool to ro
19、om temperature. 6.3.2. Screen over a 300-m (No. 50) sieve using a mechanical shaker until less than 1 percent of the retained material passes the sieve in 1 min of continuous sieving. 6.3.3. Determine and record the mass of the retained material to the nearest 0.1 g (W2). 6.3.4. Bring the material t
20、o the saturated surface-dry (SSD) condition according to T 84. 6.4. Coarse Aggregate: 6.4.1. Thoroughly wash the sample to remove dust or other coating from the surface and dry to constant mass. 6.4.2. Cool to room temperature. Screen over a 4.75-mm (No.4) sieve using a mechanical shaker until less
21、than 1 percent of the retained material passes the sieve in 1 min of continuous sieving. Note 3Add sieves larger than the 4.75 mm (No.4) as needed to avoid overloading. 6.4.3. Determine and record the mass of the material retained on the 4.75 (No. 4) sieve to the nearest 0.1 g (W4). 6.4.4. Bring the
22、 sample to a saturated-surface dry (SSD) condition according to T 85. If during the SSD determination the material undergoes degradation in water, the material does not have to be brought to SSD condition. 7. PROCEDURE 7.1. Fine Aggregate: 7.1.1. Slowly introduce the SSD material into the heavy liqu
23、id solution (Note 2). The volume of liquid shall be at least three times the absolute volume of the material. 7.1.2. Agitate the material for at least 15 s to ensure material is thoroughly wetted and incorporated into the solution. 7.1.3. Allow the material to sit undisturbed for 1 to 2 min to ensur
24、e the heavier material has settled out of the heavy liquid. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c T 113-4 AASHTO 7.1.4. Separation of the Lightweight ParticlesPerform Either Skimming or
25、Decanting: 7.1.4.1. Skimming: 7.1.4.1.1. Skim the top surface of the solution to collect the floating particles. Remove the particles from the skimmer and retain for washing. 7.1.4.1.2. Repeat Sections 7.1.2 through 7.1.4.1.1 until no additional particles are floating on the surface. 7.1.4.2. Decant
26、ing: 7.1.4.2.1. Pour the liquid through a 300-m (No. 50) sieve into a second container, collecting only the floating particles. Ensure the heavy particles stay in the container during this process. 7.1.4.2.2. Return the decanted solution to the original container. 7.1.4.2.3. Repeat Sections 7.1.2 an
27、d 7.1.3 (agitation and resting), and Sections 7.1.4.2.1 and 7.1.4.2.2 (decanting and collection) until there are no visual signs of floating material. 7.1.5. Wash the lightweight particles over the 300-m (No. 50) sieve with water to remove the heavy liquid solution. Ensure the sample is thoroughly w
28、ashed and all of the heavy liquid solution is removed. 7.1.6. Dry the lightweight particles to constant mass. 7.1.7. Determine and record the mass of the lightweight particles to the nearest 0.1 g (W1). 7.2. Coarse Aggregate: 7.2.1. Slowly introduce the SSD material into the heavy liquid solution (N
29、ote 2) ensuring the liquid and material are maintained within the sample container. The volume of liquid shall be at least three times the absolute volume of the material. 7.2.2. Agitate the material for at least 15 s to ensure material is thoroughly wetted and incorporated into the solution. 7.2.3.
30、 Skim the top surface of the solution collecting the floating particles. Remove the particles from the skimmer and retain for washing. 7.2.4. Repeat Sections 7.2.2 and 7.2.3 until no additional particles are floating on the surface. 7.2.5. Wash the lightweight particles over the 4.75-mm (No. 4) siev
31、e with water to remove the heavy liquid solution. Ensure the sample is thoroughly washed and all of the heavy liquid solution is removed. 7.2.6. Dry the retained material to a constant mass. 7.2.7. Determine and record the mass to the nearest 0.1g (W3). 7.3. Determine the specific gravity of the hea
32、vy liquid. This must be within 0.01 of the original heavy liquid; repeat procedure when specific gravity of the heavy liquid is outside this tolerance. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS
33、-1c T 113-5 AASHTO 8. CALCULATION 8.1. Calculate the percentage of lightweight particles as follows: 8.1.1. Fine Aggregate: 12100fWLW= (1) where: Lf= percentage of fine lightweight particles, W1= dry mass of fine lightweight particles, and W2= dry mass of specimen coarser than 300-m (No. 50) sieve.
34、8.1.2. Coarse Aggregate: 34100cWLW= (2) where: Lc= percentage of coarse lightweight particles, W3= dry mass of coarse lightweight particles, and W4= dry mass of specimen coarser than 4.75-mm (No. 4) sieve. 9. REPORT 9.1. The report shall include the following: 9.1.1. The mass of the test sample used
35、; 9.1.2. Identification of the aggregate as to source, type, and nominal maximum size; 9.1.3. Type and specific gravity of heavy liquid used for the test; and 9.1.4. Percentage of lightweight particles calculated to the nearest 0.1 percent. 10. PRECISION AND BIAS 10.1. PrecisionNo interlaboratory or
36、 intralaboratory studies have been conducted using this test method to determine precision indices. The committee is seeking pertinent data from users of the test method. 10.2. BiasBias of the test method may be estimated by running separate specific gravity and absorption determinations on individu
37、al particles of the separate sink, or float fractions, or both. 11. KEYWORDS 11.1. Aggregate; floating particles; heavy liquid; lightweight particles; specific gravity. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.
