AASHTO R 66-2016 Standard Practice for Sampling Asphalt Materials.pdf

1、Standard Practice for Sampling Asphalt Materials AASHTO Designation: R 66-161 Release: Group 3 (August 2016) American 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 M

2、aterials AASHTO Designation: R 66-161Release: Group 3 (August 2016) 1. 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 storag

3、e or shipping of asphalt materials. 1.2. The values stated in SI 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,

4、 associated with its use. It is the responsibility of the user 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 mate

5、rial being sampled. Care shall be exercised to ensure that samples 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 alterat

6、ions render the sample to not be representative of the material 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 al

7、so occur due to the presence of cleaning agents, either in the 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. 1 L (1 qt) of emulsif

8、ied asphalt. 4.2. The sample size of semisolid or solid materials shall be as follows: 4.2.1. From barrels, drums, or cakes1 to 2 kg (2 to 3 lb). 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2a R

9、66-2 AASHTO 5. CONTAINERS 5.1. Type of Containers: 5.1.1. Containers 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 wi

10、de-mouth jars or bottles with screw caps. 5.2. Size of Containers: 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

11、together tightly. 6.2. Take care to prevent the sample from becoming 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

12、clean, dry cloth. 6.4. Emulsified asphalt samples shall be protected 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 b

13、een entrapped. In addition, the sampling container should be completely filled to minimize a skin formation at the air-emulsion interface. 2016 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 AA

14、SHTO Note 2An alternate to completely filling a container with emulsified 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 p

15、rior to testing. 6.5. Transferring samples from one container to 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

16、 for identification if they can be securely fastened to the container 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

17、up to 200C (392F). 6.6.1. Label information shall include at a minimum: 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 o

18、ne of the following methods: 7.1.1. Tank Tap MethodUsing valves or taps as shown in Figure 2, at the top, middle, and lower locations of the tank, draw a 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 v

19、alve is available at the lower location, draw a sample 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 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication

20、 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 use is shown

21、 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 transferred to

22、 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 mechanical agit

23、ators 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 TANKS, OR DIS

24、TRIBUTOR 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 valve, the

25、 valve shall be thoroughly flushed. A minimum of 4 L (1 gal) shall be drawn through the sample valve and discarded. 1211107654321 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2a R 66-5 AASHTO 8.2.

26、 When permitted by the purchaser, the following methods may be used to obtain representative samples: 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

27、container must be used to take 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 discha

28、rge line. This outlet assembly 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 draw

29、n from this sampling valve and 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. Note 3Take care when sampling from a distributor to ensure the bar and nozzle are flushed prior to sam

30、pling to avoid contamination. Figure 4Typical Detachable Sampling Pipe Fitting Device FlowBrass Cap76-mm (3-in.)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 Si

31、de Outlet(horizontal position) 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2a R 66-6 AASHTO 9. SAMPLING FROM TANKERS AND BARGES 9.1. For liquid asphalt materials (including all cutbacks liquefied

32、 by heating), samples from the top, middle, and lower levels shall be taken using the methods described in Section 7.1. 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 wh

33、ich the material is flowing by insertion 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

34、than one-eighth the diameter of the 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 entir

35、e loading or unloading operation. At 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

36、Valve Samplers 10.1.1. When sampling 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 le

37、ast ten 4-L (1-gal) samples. At 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. 11. SAMPLING FROM PIPE LINES DURING ASPHALT

38、 BINDER PRODUCTION 11.1. Obtain the sample from the line feeding the mixing plant while the plant is in operation. The sampling valve will be located downstream of any blending or other processing. A suitable in-line sampling pipe is shown in Figure 5. The diameter of the sampling pipe shall not be

39、more than one-eighth of the diameter of the pipe line, and its opening should be turned to face the flow of the liquid. The pipe shall be provided with a valve or plug cock and shall discharge into a sample receiver. Before the sample is taken from the sample valve, a minimum of 4 L (1 gal) shall be

40、 drawn through the sample valve and discarded. 2016 by 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 12. SAMPLING FROM DRUMS OR BARRELS 12.1. After thorough mixing, samples of liquid aspha

41、lt 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 each barrel or drum selected at random. 13. SAMPLING SEMISOLID MATERIALS 13.1. Drums, Barrels, Cartons, and BagsWhere the lot of material to be sampled is obviously from a

42、 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 test to conform to th

43、e 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. Table 1Sample Size Selection C

44、ontainers 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 to 512 8 513 to 729 9 730 to 1000 10 1001 to 1331 11 13.2. 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.

45、 A clean hatchet may be used if the material is hard enough to shatter or a broad, stiff putty knife may be used 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

46、from a single run or batch of the producer, all samples from the lot shall be melted and thoroughly mixed, and an 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,

47、 a composite 4-L (1-gal) sample shall be prepared for examination from each batch. Where it is not possible to differentiate between the various batches, each sample shall be examined separately. 14. SAMPLING AT POINT OF SHIPMENT DELIVERY 14.1. Sampling of asphalt materials shall be completed as soo

48、n as practical after the asphalt material has arrived at the plant site, storage site, or job destination or at the time of unloading. 14.2. 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 sha

49、ll be taken to represent a maximum of 40 m3(10,000 gal). 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-2a R 66-8 AASHTO 14.3. Sampling shall be completed by one of the following methods: 14.3.1. In accordance with Section 7, or 14.3.2. By bleeding through a sample valve or tap in the transfer line during the unloading of the approximate middle-third of the load. Note 4Thoroughly flush the line before sampling. A minimum of 4 L (1 gal) shall be drawn through the