AASHTO R 66-2015 Standard Practice for Sampling Asphalt Materials.pdf

1、Standard Practice for Sampling Asphalt Materials AASHTO Designation: R 66-151American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2a R 66-1 AASHTO Standard Practice for Sampling Asphalt Materials AASHTO Designation: R 6

2、6-1511. SCOPE 1.1. This standard applies to sampling asphalt materials at production facilities, at storage facilities, or at the point of delivery. Samples may be taken from tanks, stockpiles, vehicles, or containers used for the storage or shipping of asphalt materials. 1.2. The values stated in S

3、I units are to be regarded as the standard. The inch-pound units are presented in parentheses for informational purposes and may not be exact equivalents. 1.3. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user

4、of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. SIGNIFICANCE AND USE 2.1. Sampling is a critical step in determining the quality of the material being sampled. Care shall be exercised to ensure that samp

5、les are representative of the material in the line or vessel being sampled. 2.1.1. Alterations of the materials being sampled, such as the use of filters or screens in the sampling devices or nozzles, shall not occur because such alterations render the sample to not be representative of the material

6、 remaining in the line or vessel being sampled. 3. INTERFERENCES 3.1. Contamination of samples can occur because of residual amounts of other types and grades of asphalt remaining in the line or vessel being sampled. Contamination can also occur due to the presence of cleaning agents, either in the

7、line or vessel being sampled or remaining on the sampling devices used. 4. SIZE OF SAMPLES 4.1. The minimum sample size for liquid asphalt material shall be as follows: 4.1.1. 1 L (1 qt) of asphalt binder, or 4.1.2. 4 L (1 gal) of emulsified asphalt. 4.2. The sample size of semisolid or solid materi

8、als shall be as follows: 4.2.1. From barrels, drums, or cakes1 to 2 kg (2 to 3 lb). 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a R 66-2 AASHTO 5. CONTAINERS 5.1. Type of Containers: 5.1.1. Conta

9、iners for liquid asphalt materials, except emulsified asphalt, shall be double-seal friction-top cans, square cans with screw tops, or small-mouth cans with screw caps. 5.1.2. Containers for emulsified asphalt samples shall be plastic wide-mouth jars or bottles with screw caps. 5.2. Size of Containe

10、rs: 5.2.1. The size of the container shall correspond to the required amount of sample. Figure 1Examples of Sample Containers 6. PROTECTION AND PRESERVATION OF SAMPLES 6.1. Sample containers shall be new. The top and container shall fit together tightly. 6.2. Take care to prevent the sample from bec

11、oming contaminated. Immediately after filling it, tightly seal the container. 6.3. The filled sample container shall not be submerged in solvent, nor shall it be wiped with a solvent-saturated cloth. If cleaning is necessary, use only a clean, dry cloth. 6.4. Emulsified asphalt samples shall be prot

12、ected from freezing. Note 1When sampling emulsified asphalt, do not sample material under pressure. Pressure may allow air entrapment which could result in erroneous test results. Bubbles in the material are one indication that air has been entrapped. In addition, the sampling container should be co

13、mpletely filled to minimize a skin formation at the air-emulsion interface. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a R 66-3 AASHTO Note 2An alternate to completely filling a container with e

14、mulsified asphalt is to fill the container until a small amount of space remains. Squeeze the container to cause the contents to fill to the top. Place the cap and securely tighten it. The space remaining will aid in mixing the sample prior to testing. 6.5. Transferring samples from one container to

15、 another shall be avoided if possible. 6.6. Immediately after filling, sealing, and cleaning, properly identify the sample containers with a suitable marker. Write on the container itself, not on the lid. Labels or tags also may be used for identification if they can be securely fastened to the cont

16、ainer in such a manner as to ensure that they will not be lost in transit. Labels or tags shall not be attached to containers by using the lids to secure them. All identification materials shall maintain their integrity at temperatures up to 200C (392F). 6.6.1. Label information shall include at a m

17、inimum: material type, source and sample date. 7. SAMPLING AT PLACE OF MANUFACTURE 7.1. Bulk Storage Tanks Not Equipped with Mechanical Agitators (Liquid Asphalt Materials or Materials Liquefied by Heating)Samples shall be obtained by one of the following methods: 7.1.1. Tank Tap MethodUsing valves

18、or taps as shown in Figure 2, at the top, middle, and lower locations of the tank, draw a 1- to 4-L (1-qt to 1-gal) sample from each location after clearing the line by drawing and discarding a minimum of 4 L (1 gal) of the material. In the event that only one valve is available at the lower locatio

19、n, draw a 1- to 4-L (1-qt to 1-gal) sample from the lower location after clearing the line by drawing and discarding a minimum of 4 L (1 gal) of the material. Figure 2Examples of Tank Taps and Valves 2015 by the American Association of State Highway and Transportation Officials.All rights reserved.

20、Duplication is a violation of applicable law.TS-2a R 66-4 AASHTO 7.1.2. Thief Sampler Method (Not Suitable for Asphalt Binders)Samples shall be taken at the top, middle, and lower levels of the tank by lowering a thief sampler into the material. A satisfactory type of sampler with instructions for u

21、se is shown in Figure 3. Note: This type of sampler is lowered into the tank with the bottom valve open (there is no top closure). When the desired depth is reached, the lowering chain is given a snap tug which closes the bottom valve. The sampler is then withdrawn from the tank and the contents tra

22、nsferred to the sample container. This sampler may be used for repetitive sampling in the same tank. Figure 3Example of a Thief Sampler 7.2. Bulk Storage Tanks (Liquid Asphalt Materials or Materials Liquefied by Heating) Equipped with Mechanical AgitatorsWhen the tank is equipped with operating mech

23、anical agitators which, by observation through the sampling or inspection hatch, are performing adequate mixing of the tank contents, a single sample taken by any of the methods described in Sections 7.1.1 or 7.1.2 will be satisfactory to use for test purposes. 8. SAMPLING FROM TANK CARS, VEHICLE TA

24、NKS, OR DISTRIBUTOR TRUCKS 8.1. Each delivery vehicle or distributor shall be equipped with a sampling valve similar in design to those shown in Figure 2. It shall be installed at least 305 mm (1 ft) from the shell and clearly labeled as a “Sampling Valve.” Before the sample is taken from the sample

25、 valve, a minimum of 4 L (1 gal) shall be drawn through the sample valve and discarded. 8.2. When permitted by the purchaser, the following methods may be used to obtain representative samples: 1211107654321 2015 by the American Association of State Highway and Transportation Officials.All rights re

26、served. Duplication is a violation of applicable law.TS-2a R 66-5 AASHTO 8.2.1. Samples of liquid asphalt materials and materials liquefied by heating may be taken by the “dip method” using a clean wide-mouth plastic jar or friction-top can in a suitable holder. A clean container must be used to tak

27、e each sample, and the material sampled shall then be transferred to another new and clean container for retaining or testing the sample. 8.2.2. A detachable or permanent sampling pipe fitting, similar in design to the one shown in Figure 4, may be inserted in the discharge line. This outlet assembl

28、y is to be inserted into the discharge line between the unloading pipe and hose as close to the end as is practical. The sample shall be taken after one third and not more than two thirds of the load has been removed. Before the sample is taken, 4 L (1 gal) shall be drawn from this sampling valve an

29、d discarded. The sample shall be taken slowly. 8.2.3. If the distributor is not equipped with a sampling valve, a sample may be obtained from a nozzle on the spray bar. Figure 4Typical Detachable Sampling Pipe Fitting Device 9. SAMPLING FROM TANKERS AND BARGES 9.1. For liquid asphalt materials (incl

30、uding all cutbacks liquefied by heating), samples from the top, middle, and lower levels shall be taken using the methods described in Section 7.1. 9.2. For all other materials liquefied by heating, a sample from the top level only shall be taken by the dip or thief method. FlowBrass Cap76-mm (3-in.

31、)I.D. Pipe, 305 mm(12 in.) in length13-mm I.D. PipeBrass Capsand Filling13-mm (1/2-in.) I.D. Pipe13-mm (1/2-in.) ValveSide Outlet (vertical position)End ViewTop View13-mm (1/2-in.) Valve Side Outlet(horizontal position) 2015 by the American Association of State Highway and Transportation Officials.A

32、ll rights reserved. Duplication is a violation of applicable law.TS-2a R 66-6 AASHTO 10. SAMPLING FROM PIPE LINES DURING LOADING OR UNLOADING 10.1. When tankers and barges are being loaded or unloaded, samples may conveniently be taken from the pipe line through which the material is flowing by inse

33、rtion of a sampling pipe into a rising section of the pipe line on the discharge side of the pump or in a completely filled line in which gravity creates the materials flow. A suitable in-line sampling pipe is shown in Figure 5. The sampling pipe shall be not more than one-eighth the diameter of the

34、 pipe line and its opening should be turned to face the flow of the liquid. This pipe shall be provided with a valve or plug cock and shall discharge into a sample receiver. At least three 4-L (1-gal) samples shall be taken at uniform intervals throughout the entire loading or unloading operation. A

35、t the completion of the loading or unloading operation, the individual 4-L (1-gal) samples shall be combined and thoroughly mixed without altering their characteristics, then a 4-L (1-gal) sample shall be taken from the composite. Figure 5Examples of Transfer Line Valve Samplers 10.1.1. When samplin

36、g tankers or barges less than 4000 m3(25,000 barrels) capacity, at least five 4-L (1-gal) samples shall be taken at uniform intervals throughout the entire loading or unloading operation. Tankers or barges of 4000 m3(25,000 barrels) or larger capacity require at least ten 4-L (1-gal) samples. At com

37、pletion of the loading or unloading operation, the individual 4-L (1-gal) samples shall be combined and thoroughly mixed without altering their characteristics, then a 4-L (1-gal) sample shall be taken from the composite. 11. SAMPLING FROM DRUMS OR BARRELS 11.1. After thorough mixing, samples of liq

38、uid asphalt material from barrels or drums shall be secured by the methods described in Section 7.1 by taking 1 L (1 qt) of material from packages selected at random according to Section 12. 12. SAMPLING SEMISOLID MATERIALS 12.1. Drums, Barrels, Cartons, and BagsWhere the lot of material to be sampl

39、ed is obviously from a single run or batch of the producer, one container shall be selected at random and sampled as described below. Where the lot of material to be sampled is not obviously from a single run or batch of the producer, or where the single sample selected as described above fails on a

40、 test to conform to the requirements of the specifications, a number of containers equivalent to the cube root of the total number of containers in the lot shall be selected at random. The following table is given, showing the number of samples to be selected for shipments of various sizes. 2015 by

41、the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2a R 66-7 AASHTO Table 1Sample Size Selection Containers in Shipment Containers Selected 2 to 8 2 9 to 27 3 28 to 64 4 65 to 125 5 126 to 216 6 217 to 343 7 344

42、 to 512 8 513 to 729 9 730 to 1000 10 1001 to 1331 11 12.2. Samples shall be taken from at least 75 mm (3 in.) below the surface and at least 75 mm (3 in.) from the side of the container. A clean hatchet may be used if the material is hard enough to shatter or a broad, stiff putty knife may be used

43、if the material is soft. When more than one container in a lot is sampled, each individual sample shall have a mass of not less than 0.1 kg (1/4lb). When the lot of material is obviously from a single run or batch of the producer, all samples from the lot shall be melted and thoroughly mixed, and an

44、 average 4-L (1-gal) sample taken from the combined material for examination. If more than a single run or batch of the producer is included and the batches can be clearly differentiated, a composite 4-L (1-gal) sample shall be prepared for examination from each batch. Where it is not possible to di

45、fferentiate between the various batches, each sample shall be examined separately. 13. SAMPLING AT POINT OF SHIPMENT DELIVERY 13.1. Sampling of asphalt materials shall be completed as soon as practical after the asphalt material has arrived at the plant site, storage site, or job destination or at t

46、he time of unloading. 13.2. The required number of samples shall be taken from each delivery of asphalt material. In the case of small delivery units such as distributors, the samples shall be taken to represent a maximum of 40 m3(10,000 gal). 13.3. Sampling shall be completed by one of the followin

47、g methods: 13.3.1. In accordance with Section 7, or 13.3.2. By bleeding through a sample valve or tap in the transfer line during the unloading of the approximate middle-third of the load. 13.4. Tests for material acceptability shall be performed on one of the samples taken. Retain the other samples

48、 for confirmation if the first sample tested fails to comply with requirements. 14. KEYWORDS 14.1. Asphalt binder; asphalt materials; emulsified asphalt; liquid asphalts; sampling; semisolid materials. 1Formerly T 40. First published as a standard practice in 2015. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.