1、Standard Method of Test for Resistance to Plastic Flow of Asphalt Mixtures Using Marshall Apparatus AASHTO Designation: T 245-15 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001TS-2d T 245-1 AASHTO Standard Method of T
2、est for Resistance to Plastic Flow of Asphalt Mixtures Using Marshall Apparatus AASHTO Designation: T 245-15 1. SCOPE 1.1. This method covers the measurement of the resistance to plastic flow of cylindrical specimens of asphalt mixture loaded on the lateral surface by means of the Marshall apparatus
3、. This method is for use with mixtures containing asphalt binder or asphalt cutback and aggregate up to 25.4-mm (1-in.) maximum size. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: R 68, Preparation of Asphalt Mixture Specimens by Means of the Marshall Compactor T 166, Bulk Specific Gravity (Gmb) of
4、 Compacted Hot Mix Asphalt (HMA) Using Saturated Surface-Dry Specimens T 275, Bulk Specific Gravity (Gmb) of Compacted Hot Mix Asphalt (HMA) Using Paraffin-Coated Specimens T 331, Bulk Specific Gravity (Gmb) and Density of Compacted Hot Mix Asphalt (HMA) Using Automatic Vacuum Sealing Method 2.2. AS
5、TM Standards: C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials D3549/D3549M, Standard Test Method for Thickness or Height of Compacted Bituminous Paving Mixture Specimens 3. APPARATUS 3.1. Breaking Head (Figure 1)Shall consist of upper a
6、nd lower cylindrical segments or test heads having an inside radius of curvature of 50.8 mm (2 in.) accurately machined. The lower segment shall be mounted on a base having two perpendicular guide rods or posts extending upward. Guide sleeves in the upper segment shall be in such a position as to di
7、rect the two segments together without appreciable binding or loose motion on the guide rods. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.Figure 1Breaking Head TS-2dT245-2AASHTO 2015 by the American
8、Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2d T 245-3 AASHTO 3.2. Loading JackThe loading jack (Figure 2) shall consist of a screw jack mounted in a testing frame and shall produce a uniform vertical movement of 50.8
9、 mm (2 in.)/min. An electric motor may be attached to the jacking mechanism. Figure 2Loading Jack Note 1Instead of the loading jack, a mechanical or hydraulic testing machine may be used, provided the rate of movement can be maintained at 50.8 mm (2 in.)/min while the load is applied. 3.3. Ring Dyna
10、mometer AssemblyOne-ring dynamometer (Figure 2) of 22.2-kN (5000-lb) capacity and sensitivity of 44.5 N (10 lb) up to 4.45 kN (1000 lb) and 111.2 N (25 lb) between 4.45 and 22.2 kN (1000 and 5000 lb) shall be equipped with a micrometer dial. The micrometer dial shall be graduated in 0.0025 mm (0.000
11、1 in.) increments. Upper and lower ring dynamometer attachments are required for fastening the ring dynamometer to the testing frame and transmitting the load to the breaking head. Instead of the ring dynamometer assembly, any suitable load-measuring device may be used, provided the capacity and sen
12、sitivity satisfy the above requirements. 3.4. FlowmeterThe flowmeter shall consist of a guide sleeve and a gauge. The activating pin of the gauge shall slide inside the guide sleeve with a slight amount of frictional resistance. The guide sleeve shall slide freely over the guide rod of the breaking
13、head. The flowmeter gauge shall be adjusted to zero when placed in position on the breaking head when each individual test specimen is inserted between the breaking head segments. Graduations of the flowmeter gauge shall be in 0.25-mm (0.01-in.) divisions. Instead of the flowmeter, a micrometer dial
14、 or stressstrain recorder graduated in 0.25 mm (0.01 in.) increments may be used to measure flow. 3.5. Ovens or Hot PlatesOvens or hot plates shall be provided for heating aggregates, asphalt material, specimen molds, compaction hammers, and other equipment to the required mixing and 2015 by the Ame
15、rican Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2d T 245-4 AASHTO molding temperatures. It is recommended that the heating units be thermostatically controlled so as to maintain the required temperature within 2.8C
16、(5F). Suitable shields, baffle plates, or sand baths shall be used on the surfaces of the hot plates to minimize localized overheating. 3.6. Water BathThe water bath shall be at least 152.4 mm (6 in.) deep and shall be thermostatically controlled so as to maintain the bath at 60 1C (140 2F) or 37.8
17、1C (100 2F). The tank shall have a perforated false bottom or be equipped with a shelf for supporting specimens 50.8 mm (2 in.) above the bottom of the bath. 3.7. Air BathThe air bath for asphalt cutback mixtures shall be thermostatically controlled and shall maintain the air temperature at 25 1C (7
18、7 2F). 3.8. ThermometersFor water and air baths sensitive to 0.2C (0.4F) with a range sufficient to determine the specified bath temperature. 3.9. Vernier CalipersCalipers readable to 0.1 mm (0.004 in.) 3.10. MiscellaneousGlovesFor handling hot equipment and other gloves for removing specimens from
19、water bath. 4. TEST SPECIMENS 4.1. Number and Dimension of SpecimensThree cylindrical specimens, 101.6 0.1 mm (4.0 0.05 in.) in diameter and ranging from 25.4 mm (1.0 in.) to 76.2 mm (3.0 in.) tall, are recommended. Prepare specimens in accordance with AASHTO R 68. 4.2. Roadway Core SpecimensCore sp
20、ecimens meeting the dimensional requirements of Section 4.1 may be collected in accordance with D5361/D5361M. 5. PROCEDURE 5.1. Measure specimen height in accordance with ASTM D3549/D3549M. 5.2. Bring the specimens prepared with asphalt cement to the specified temperature by immersing in the water b
21、ath 30 to 40 min or placing in the oven for 2 h. Maintain the bath or oven temperature at 60 1C (140 1.8F) for the asphalt binder specimens. Bring the specimens prepared with asphalt cutback to the specified temperature by placing them in the air bath for a minimum of 2 h. Maintain the air bath temp
22、erature at 25 1C (77 1.8F). Thoroughly clean the guide rods and the inside surfaces of the test heads prior to performing the test, and lubricate the guide rods so that the upper test head slides freely over them. The testing-head temperature shall be maintained between 21.1 to 37.8C (70 to 100F) us
23、ing a water bath when required. Remove the specimen from the water bath, oven, or air bath, and place in the lower segment of the breaking head. Place the upper segment of the breaking head on the specimen, and place the complete assembly in position on the testing machine. Place the flowmeter, wher
24、e used, in position over one of the guide rods and adjust the flowmeter to zero while holding the sleeve firmly against the upper segment of the breaking head. Hold the flowmeter sleeve firmly against the upper segment of the breaking head while the test load is being applied. 5.3. Apply the load to
25、 the specimen by means of the constant rate of movement of the loadjack or testing-machine head of 50.8 mm (2 in.) per minute until the maximum load is reached and the load decreases as indicated by the dial. Record the maximum load noted on the testing machine or converted from the maximum micromet
26、er dial reading. Release the flowmeter sleeve or note the micrometer dial reading, where used, the instant the maximum load begins to decrease. Note and record the indicated flow value or equivalent units intwenty-five hundredths of a millimeter 2015 by the American Association of State Highway and
27、Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2d T 245-5 AASHTO (hundredths of an inch) if a micrometer dial is used to measure the flow. The elapsed time for the test from removal of the test specimen from the water bath to the maximum load determinat
28、ion shall not exceed 30 s. Note 2For core specimens, correct the load when thickness is other than 63.5 mm (21/2in.) by using the proper multiplying factor from Table 2. Table 1Stability Correlation Ratiosa,bVolume of Specimen, cm3Approximate Thickness of Specimen, in. mm Corre- lation Ratio 200 to
29、213 1 25.4 5.56 214 to 225 11/1627.0 5.00 226 to 237 11/828.6 4.55 238 to 250 13/1630.2 4.17 251 to 264 11/431.8 3.85 265 to 276 15/1633.3 3.57 277 to 289 13/834.9 3.33 290 to 301 17/1636.5 3.03 302 to 316 11/238.1 2.78 317 to 328 19/1639.7 2.50 329 to 340 15/841.3 2.27 341 to 353 111/1642.9 2.08 35
30、4 to 367 13/444.4 1.92 368 to 379 113/1646.0 1.79 380 to 392 17/847.6 1.67 393 to 405 115/1649.2 1.56 406 to 420 2 50.8 1.47 421 to 431 21/1652.4 1.39 432 to 443 21/854.0 1.32 444 to 456 23/1655.6 1.25 457 to 470 21/457.2 1.19 471 to 482 25/1658.7 1.14 483 to 495 23/860.3 1.09 496 to 508 27/1661.9 1
31、.04 509 to 522 21/263.5 1.00 523 to 535 29/1665.1 0.96 536 to 546 25/866.7 0.93 547 to 559 211/1668.3 0.89 560 to 573 23/469.9 0.86 574 to 585 213/1671.4 0.83 586 to 598 27/873.0 0.81 599 to 610 215/1674.6 0.78 611 to 625 3 76.2 0.76 aThe measured stability of a specimen multiplied by the ratio for
32、the thickness of the specimen equals the corrected stability for a 63.5-mm (21/2-in.) specimen. bVolume-thickness relationship is based on a specimen diameter of 101.6 mm (4 in.). 6. REPORT 6.1. The report shall include the following information: 6.1.1. Type of sample tested (laboratory sample or pa
33、vement core specimen); 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2d T 245-6 AASHTO Note 3For core specimens, the height of each test specimen in millimeters (or inches) shall be reported. 6.1.2.
34、 Average maximum load in pounds-force (or newtons) of at least three specimens, corrected when required; 6.1.3. Average flow value, in twenty-five hundredths of a millimeter (hundredths of an inch), of three specimens; and 6.1.4. Test temperature. 7. PRECISION AND BIAS 7.1. Criteria for judging the
35、acceptability of Marshall stability and flow test results obtained by this method are shown in Table 3. Table 3Precision Estimates Test and Type of Index Coefficient of Variation, % of meanaAcceptable Range of Two Test Results, % of meanaMarshall stability Within laboratory precision 6 16 Between la
36、boratory precision 16 43 Marshall flow Within laboratory precision Between laboratory precision 9 20 26 58 aThese values represent the 1s percent and d2s percent limits as described in ASTM C670. 7.2. The precision estimates noted in Table 3 are based on specimens compacted with mechanical and manua
37、l hammers and include dense graded mixtures with limestone and gravel aggregates, and different asphalt binders. 8. KEYWORDS 8.1. Asphalt; binder; cutback; cylindrical specimens; Marshall apparatus; mixtures; plastic flow; stability. 9. REFERENCES 9.1. ASTM. D5361/D5361M, Standard Practice for Sampling Compacted Bituminous Mixtures for Laboratory Testing. 9.2. ASTM. E11, Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
