AASHTO T 269-2014 Standard Method of Test for Percent Air Voids in Compacted Dense and Open Asphalt Mixtures.pdf

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1、Standard Method of Test for Percent Air Voids in Compacted Dense and Open Asphalt Mixtures AASHTO Designation: T 269-141ASTM Designation: D3203/D3203M-11 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-2c T 269-1 A

2、ASHTO Standard Method of Test for Percent Air Voids in Compacted Dense and Open Asphalt Mixtures AASHTO Designation: T 269-141ASTM Designation: D3203/D3203M-11 1. SCOPE 1.1. This method covers the determination of the percent air voids (Va) in compacted dense and open asphalt mixtures. 1.2. This sta

3、ndard may 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 establish appropriate safety and health practices and determine the applicability o

4、f regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: T 166, Bulk Specific Gravity (Gmb) of Compacted Hot Mix Asphalt (HMA) Using Saturated Surface-Dry Specimens T 209, Theoretical Maximum Specific Gravity (Gmm) and Density of Hot Mix Asphalt (HMA) T 275, Bulk Specifi

5、c 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. ASTM Standards: D3203/D3203M, Standard Test Method for Percent Air Voids in Compacted Dense

6、and Open Bituminous Paving Mixtures D3549/D3549M, Standard Test Method for Thickness or Height of Compacted Bituminous Paving Mixture Specimens D4460, Standard Practice for Calculating Precision Limits Where Values are Calculated from Other Test Methods E1547, Standard Terminology Relating to Indust

7、rial and Specialty Chemicals 3. TERMINOLOGY 3.1. The terms specific gravity and density used in this test method are in accordance with ASTM E1547. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c T

8、 269-2 AASHTO 3.2. Definitions: 3.2.1. air voids (Va)the pockets of air between the asphalt-coated aggregate particles in a compacted asphalt mixture. 3.2.2. dense asphalt mixtureasphalt mixtures in which the air voids (Va) are less than 10 percent when compacted. 3.2.3. open asphalt mixtureasphalt

9、mixtures in which the air voids (Va) are 10 percent or more when compacted. 3.2.3.1. For borderline cases, an asphalt mixture shall be designated as an open asphalt mixture if the calculated percent air voids (Va), based on either Section 6.1 or 6.2, are 10 percent or more. 4. SIGNIFICANCE AND USE 4

10、.1. The percent air voids (Va) in an asphalt mixture is used as one of the criteria in the design methods and for evaluation of the compaction achieved on asphalt paving projects. 5. SAMPLING 5.1. Samples for testing shall consist of specimens from laboratory-molded mixtures or cores from field-comp

11、acted mixtures. 6. PROCEDURE 6.1. For dense asphalt mixtures, determine the bulk specific gravity (Gmb) of the compacted mixture by either T 166, T 275, or T 331. Determine the theoretical maximum specific gravity (Gmm) in accordance with T 209 on a comparable asphalt mixture to avoid the influence

12、of differences in gradation, asphalt content, etc. 6.2. For open asphalt mixtures, use either of the following methods: 6.2.1. Automatic Vacuum Sealing MethodDetermine the bulk specific gravity (Gmb) of the compacted mixture by T 331. Determine the theoretical maximum specific gravity (Gmm) in accor

13、dance with T 209 on a comparable asphalt mixture to avoid the influence of differences in gradation, asphalt content, etc. 6.2.2. Volume MethodDetermine the density of a regularly shaped specimen of compacted mixture from its dry mass (in grams) and its volume (in cubic centimeters). Obtain the heig

14、ht of the specimen by ASTM D3549/D3549M. Measure the diameter of the specimen at four locations, and average the measurements. Calculate the volume of the specimen based on the average height and diameter measurement. Convert the density to bulk specific gravity (Gmb) by dividing by 0.99707 g/cm3or

15、997 kg/m3, the density of water at 25C (77F). Determine the theoretical maximum specific gravity (Gmm) in accordance with T 209 on a comparable asphalt mixture to avoid the influence of differences in gradation, asphalt content, etc. For reference purposes, determine both the bulk specific gravity (

16、Gmb) and the theoretical maximum specific gravity (Gmm) on portions of the same sample of compacted asphalt mixture. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c T 269-3 AASHTO 7. CALCULATIONS 7

17、.1. Calculate the percent air voids (Va) in a compacted asphalt mixture as follows: 100 1mbammGVG= (1) or 100mm mbammGGVG=(2) where: Gmb= the bulk specific gravity; and Gmm= the theoretical maximum specific gravity. 7.2. Report the percent air voids (Va) to one decimal place. 8. PRECISION AND BIAS 8

18、.1. The precision of this test method depends on the precision of test methods for bulk specific gravity (Gmb) and theoretical maximum specific gravity (Gmm). It is computed by a procedure described in ASTM D4460. Because the computation for percent air voids (Va) in Section 7.1 involves the quotien

19、t of bulk specific gravity (Gmb) divided by the theoretical maximum specific gravity (Gmm), the quotient formula is used: 22 224+ =xyxyyxy(3) where: x/y= the standard deviation for determining the precision limits of test results for a standard based on the quotient of two test results from two othe

20、r standards; x= the mean (average) value of the x standard bulk specific gravity (Gmb) test results; y= the mean (average) value of the y standard theoretical maximum specific gravity (Gmm) test results; x= the standard deviation from the precision statement of the x standard; and y= the standard de

21、viation from the precision statement of the y standard. Note 1The x standard (T 166, T 275, or T 331) is used to compute bulk specific gravity (Gmb), and the y standard (T 209) is used to compute theoretical maximum specific gravity (Gmm). 8.2. Criteria for judging the acceptability of percent air v

22、oids (Va) test results that are obtained by using x standard and y standard for nonporous aggregates are: 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-2c T 269-4 AASHTO x Standard and y Standard Te

23、st and Type Index Standard Deviation (1s%) Acceptable Range of Two Results (d2s%) T 166 and T 209 (Method A) Single-operator precision 0.21 0.59 T 166 and T 209 (Method A) Multilaboratory precision 0.40 1.13 T 166 and T 209 (Method B) Single-operator precision 0.26 0.74 T 166 and T 209 (Method B) Mu

24、ltilaboratory precision 0.46 1.30 T 275 and T 209 (Method A) Single-operator precision 0.34 0.96 T 275 and T 209 (Method A) Multilaboratory precision T 275 and T 209 (Method B) Single-operator precision 0.37 1.05 T 275 and T 209 (Method B) Multilaboratory precision T 331 and T 209 (Method A) Single-

25、operator precision 0.53 1.50 T 331 and T 209 (Method A) Multilaboratory precision 0.62 1.75 T 331 and T 209 (Method B) Single-operator precision 0.55 1.56 T 331 and T 209 (Method B) Multilaboratory precision 0.66 1.87 APPENDIX (Nonmandatory Information) X1. EXAMPLE CALCULATION OF PRECISION X1.1. Ass

26、ume the following precision data: Bulk specific gravity (Gmb), x When the average of x = 2.423 and the standard deviation of x = 0.007. Theoretical maximum specific gravity (Gmm), y When the average of y = 2.523 and the standard deviation of y = 0.004. Then using Equation 2: 22 2242.523 0.007 2.423

27、0.0040.003162.523xy (X1.1) This value is in terms of air voids (Va); therefore, the value should be multiplied by 100 to convert it into a percentage. Therefore: 0.0032 100 0.32%xy (X1.2) 1Similar, but not technically identical to ASTM D3203/D3203M-11. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.