1、Standard Method of Test for Determining Aggregate Shape Properties by Means of Digital Image Analysis AASHTO Designation: TP 81-12 (2015)1American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1c TP 81-1 AASHTO Standard M
2、ethod of Test for Determining Aggregate Shape Properties by Means of Digital Image Analysis AASHTO Designation: TP 81-12 (2015)11. SCOPE 1.1. This standard covers the measurement of aggregate shape properties using the digital image analysis techniques. 1.2. This standard may involve hazardous mater
3、ials, 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 of regulatory limitations prior to
4、 use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 92, Wire-Cloth Sieves for Testing Purposes M 231, Weighing Devices Used in the Testing of Materials T 2, Sampling of Aggregates T 11, Materials Finer Than 75-m (No. 200) Sieve in Mineral Aggregates by Washing T 27, Sieve Analysis of Fine and Coa
5、rse Aggregates T 84, Specific Gravity and Absorption of Fine Aggregate T 85, Specific Gravity and Absorption of Coarse Aggregate T 248, Reducing Samples of Aggregate to Testing Size 2.2. ASTM Standards: C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construc
6、tion Materials C802, Standard Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods for Construction Materials 2.3. Other Document: National Cooperative Highway Research Program Report 555, Test Methods for Characterizing Aggregate Shape, Texture, and Ang
7、ularity 3. TERMINOLOGY 3.1. aggregate sizesieve size in which material is retained after passing the next larger sieve. 3.1.1. fine aggregateaggregate material passing a 4.75-mm (No. 4) sieve. Sieve sizes are 2.36 mm (No. 8), 1.18 mm (No. 16), 0.60 mm (No. 30), 0.30 mm (No. 50), 0.15 mm (No. 100), a
8、nd 0.075 mm (No. 200). 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-2 AASHTO 3.1.2. coarse aggregateaggregate material retained on a 4.75-mm (No. 4) sieve. Sieve sizes are 25.0 mm (1 in.),
9、 19.0 mm (3/4in.), 12.5 mm (1/2in.), 9.5 mm (3/8in.), and 4.75 mm (No. 4). 3.2. Shape Properties for Each Retained Sieve (x): 3.2.1. gradient angularity (GA)applies to both fine and coarse aggregate sizes and is related to the sharpness of the corners of two-dimensional images of aggregate particles
10、. The gradient angularity quantifies changes along a particle boundary with higher gradient values indicating a more angular shape. Gradient angularity has a relative scale of 0 to 10,000, with a perfect circle having a value of 0. Gradient Angularity: 331113niiiGAn+= (1) where: = angle of orientati
11、on of the edge points, n = the total number of points, and i = denoting the ith point on the edge of the particle. 3.2.2. texture or microtexture (TX)applies to coarse aggregate sizes only describing relative smoothness or roughness of surface features less than approximately 0.5 mm in size that are
12、 too small to affect the overall shape. Texture has a relative scale of 0 to 1000 with a smooth polished surface approaching a value of 0. ( )( )23,111,3Nn ijijTX D x yN= =(2) where: D = decomposition function, n = decomposition level, N = total number of coefficients in an image, i = 1, 2, or 3 for
13、 detailed images, j = wavelet index, and x, y = location of the coefficients in transformed domain. 3.2.3. sphericity (SP)applies to coarse aggregate sizes only and describes the overall three-dimensional shape of a particle. Sphericity has a relative scale of 0 to 1. A sphericity value of one indic
14、ates a particle has equal dimensions (cubical). 32SILddSPd= (3) where: dS= particle shortest dimension, dI= particle intermediate dimension, and dL= particle longest dimension. Note 1The term “sphericity” has been used for many years in research to describe this measurement. In principle, a cube doe
15、s not have a sphericity of one because the diagonal is 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-3 AASHTO considered to be the longest dimension. A digital image acquisition and analysi
16、s system would measure a value of one for a cube because it would be sitting in front of the camera on one of its faces and the longest dimension will be measured as the width. 3.2.4. Form 2DApplies to fine aggregate sizes only and is used to quantify the relative form from 2-dimensional images of a
17、ggregate particles. Form 2D has a relative scale of 0 to 20. A perfect circle has a Form 2D value of zero. 3600Form 2DRRR= + =(4) where: R= the radius of the particle at an angle of , and = the incremental difference in the angle. 3.2.5. flat and elongatedthose particles having a ratio of longest di
18、mension to shortest dimension greater than a specified value. Aggregate particle dimensions in an x, y, z coordinate system are: dS= particle shortest dimension, dI= particle intermediate dimension, and dL= particle longest dimension. Flatness ratio (S/L): SIdFlatnessd=(5) Elongation ratio (I/L): IL
19、dElongationd=(6) Flat and elongated value (F 13.1.2. Date of the analysis; 13.1.3. Material Sample Identificationtype, source, and size; 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-8 AASH
20、TO 13.1.4. Number of particles analyzed; and 13.1.5. Material shape property mean and standard deviation. Graphical representations of the property distributions may be included. 13.2. A sample report format is presented in Appendix X1. 14. PRECISION AND BIAS 14.1. PrecisionAn Interlaboratory Study
21、(ILS) was conducted in 2009 in accordance with ASTM C802. The ILS results were used to develop a precision statement for the test method using ASTM C670. The ILS featured eight systems, 32 laboratories, and three material sources. Table 1Precision for Sizes 25 mm, 19 mm, 12.5 mm, 9.5 mm, 4.75 mm, 2.
22、36 mm, 1.18 mm, 0.60 mm, 0.30 mm, and 0.15 mm Aggregate Shape Characteristic Within Laboratory Between Laboratories Coefficient of Variation, % of Mean Acceptable Range of Two Test Results, % of Mean Coefficient of Variation, % of Mean Acceptable Range of Two Test Results, % of Mean Angularity 2.9 8
23、.3 4.3 12.2 Texture 4.5 12.7 7.1 20.0 Dimensional ratio 1.2 3.4 2.6 7.4 Flat or elongated 2.1 5.9 3.4 9.7 Form 2D 2.7 7.7 3.5 10.0 Table 2Precision for Size 0.075 mm Aggregate Shape Characteristic Within Laboratory Between Laboratories Coefficient of Variation, % of Mean Acceptable Range of Two Test
24、 Results, % of Mean Coefficient of Variation, % of Mean Acceptable Range of Two Test Results, % of Mean Angularity 10.8 30.6 14.2 40.2 Form 2D 5.0 14.2 6.2 17.6 14.2. BiasBecause there is no accepted reference device suitable for determining the bias in this method, no statement of bias is made. 15.
25、 KEYWORDS 15.1. Aggregate; angularity; consensus property; elongated; form; shape; texture. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-9 AASHTO APPENDIX (Nonmandatory Information) X1. SA
26、MPLE REPORT Material Information Date: 5/20/09 Project: Coarse Aggregate Sample Technician: TEC Workbook Name: AIMS_Shape_3.6.xlsm Description: Include Samples Size Comment 12.5 (0.50)_33_LS_1 12.5 12.5 (0.50)_41_GRT_1 12.5 12.5 (0.50)_41_GRV_1 12.5 12.5 (0.50)_17_GRT_1 12.5 12.5 (0.50)_17_ GRV _1 1
27、2.5 12.5 (0.50)_17_LS_1 12.5 AIMS Material Summary Project Name: Coarse Aggregate Sample Date: 5/20/09 Workbook: AIMS_Shape_3.6 xlsm Technician: TEC Description: Form2D Sample Size Particles in Range Average Standard Deviation Low (6) (6) Medium (612) (12) High (1220) (20) Out of Range # % Cum % # %
28、 Cum % # % Cum % # Angularity Sample Size Particles in Range Average Standard Deviation Low (3300) (3300) Medium (33006600) (6600) High (660010000) (10000) Out of Range # % Cum % # % Cum % # % Cum % # 12.5 (0.50)_33_LS_1 12.5 50 2784.3 669.0 37 74.0% 74.0% 13 26.0% 100.0% 0 0.0% 100.0% 0 12.5 (0.50)
29、_41_GRT_1 12.5 50 3138.7 597.3 28 56.0% 56.0% 22 44.0% 100.0% 0 0.0% 100.0% 0 12.5 (0.50)_41_GRV_1 12.5 50 2791.7 978.7 35 70.0% 70.0% 15 30.0% 100.0% 0 0.0% 100.0% 0 12.5 (0.50)_17_GRT_1 12.5 50 3118.7 655.3 33 66.0% 66.0% 17 34.0% 100.0% 0 0.0% 100.0% 0 12.5 (0.50)_17_GRV_1 12.5 50 2623.1 862.9 40
30、 80.0% 80.0% 10 20.0% 100.0% 0 0.0% 100.0% 0 12.5 (0.50)_17_LS_1 12.5 50 2670.4 726.4 42 84.0% 84.0% 8 16.0% 100.0% 0 0.0% 100.0% 0 Texture Sample Size Particles in Range Average Standard Deviation Low (260) (260) Medium (260550) (550) High (5501000) (1000) Out of Range # % Cum % # % Cum % # % Cum %
31、 # 12.5 (0.50)_33_LS_1 12.5 50 281.8 98.1 22 44.0% 44.0% 28 56.0% 100.0% 0 0.0% 100.0% 0 12.5 (0.50)_41_GRT_1 12.5 50 455.5 119.8 1 2.0% 2.0% 41 82.0% 84.0% 8 16.0% 100.0% 0 12.5 (0.50)_41_GRV_1 12.5 49 211.8 131.9 35 71.4% 71.4% 14 28.6% 100.0% 0 0.0% 100.0% 1 12.5 (0.50)_17_GRT_1 12.5 50 457.4 88.
32、6 0 0.0% 0.0% 43 86.0% 86.0% 7 14.0% 100.0% 0 12.5 (0.50)_17_GRV_1 12.5 50 224.4 141.9 35 70.0% 70.0% 14 28.0% 98.0% 1 2.0% 100.0% 0 12.5 (0.50)_17_LS_1 12.5 50 252.3 84.4 32 64.0% 64.0% 17 340% 98.0% 1 2.0% 100.0% 0 2015 by the American Association of State Highway and Transportation Officials.All
33、rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-10 AASHTO AIMS Material Summary Project Name: Coarse Aggregate Sample Date: 5/20/09 Workbook: AIMS_Shape_3.6 xlsm Technician: TEC Description: Sphericity Sample Size Particles in Range Average Standard Deviation Low (0.3) (0.3
34、) Medium (0.30.7) (0.7) High (0.71.0) (1.0) Out of Range # % Cum % # % Cum % # % Cum % # 12.5 (0.50)_33_LS_1 12.5 50 0.69 0.10 0 0.0% 0.0% 28 56.0% 56.0% 22 44.0% 100.0% 0 12.5 (0.50)_41_GRT_1 12.5 49 0.62 0.09 0 0.0% 0.0% 37 75.5% 75.5% 12 24.5% 100.0% 1 12.5 (0.50)_41_GRV_1 12.5 49 0.69 0.08 0 0.0
35、% 0.0% 24 49.0% 49.0% 25 51.0% 100.0% 1 12.5 (0.50)_17_GRT_1 12.5 50 0.63 0.11 0 0.0% 0.0% 37 74.0% 74.0% 13 26.0% 100.0% 0 12.5 (0.50)_17_GRV_1 12.5 50 0.69 0.08 0 0.0% 0.0% 27 54.0% 54.0% 23 46.0% 100.0% 0 12.5 (0.50)_17_LS_1 12.5 50 0.69 0.09 0 0.0% 0.0% 27 54.0% 54.0% 23 46.0% 100.0% 0 Flat and
36、Elongated Distribution Sample Size Particles in Range L/S 1:1 L/S 2:1 L/S 3:1 L/S 4:1 L/S 5:1 Out of Range # % # % # % # % # % # 12.5 (0.50)_33_LS_1 12.5 50 50 100.0% 28 56.0% 6 12.0% 1 2.0% 0 0.0% 0 12.5 (0.50)_41_GRT_1 12.5 49 49 100.0% 43 87.8% 21 42.9% 6 12.2% 1 2.0% 1 12.5 (0.50)_41_GRV_1 12.5
37、49 49 100.0% 29 59.2% 5 10.2% 1 2.0% 0 0.0% 1 12.5 (0.50)_17_GRT_1 12.5 50 50 100.0% 40 80.0% 22 44.0% 9 18.0% 1 2.0% 0 12.5 (0.50)_17_GRV_1 12.5 50 50 100.0% 26 52.0% 4 8.0% 2 4.0% 0 0.0% 0 12.5 (0.50)_17_LS_1 12.5 50 50 100.0% 33 66.0% 7 14.0% 1 2.0% 0 0.0% 0 Flat or Elongated Distribution Sample
38、Size Particles in Range F or E 1:1 F or E 2:1 F or E 3:1 F or E 4:1 F or E 5:1 Out of Range # % # % # % # % # % # 12.5 (0.50)_33_LS_1 12.5 50 50 100.0% 10 20.0% 0 0.0% 0 0.0% 0 0.0% 0 12.5 (0.50)_41_GRT_1 12.5 49 49 100.0% 23 46.9% 4 8.2% 0 0.0% 0 0.0% 1 12.5 (0.50)_41_GRV_1 12.5 49 49 100.0% 8 16.3
39、% 0 0.0% 0 0.0% 0 0.0% 1 12.5 (0.50)_17_GRT_1 12.5 50 50 100.0% 24 48.0% 5 10.0% 0 0.0% 0 0.0% 0 12.5 (0.50)_17_GRV_1 12.5 50 50 100.0% 6 12.0% 1 2.0% 0 0.0% 0 0.0% 0 12.5 (0.50)_17_LS_1 12.5 50 50 100.0% 13 26.0% 1 2.0% 0 0.0% 0 0.0% 0 AIMS Angularity Project Name: Coarse Aggregate Sample Date: 5/2
40、0/09 Workbook: AIMS_Shape_3.6 xlsm Technician: TEC Description: # % Cum. % # % Particles in Range 300 Low (3300) 215 71.7% (3300) 71.7% 3 4 1.3% Mode #N/A 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
41、TS-1c TP 81-11 AASHTO AIMS Texture Project Name: Coarse Aggregate Sample Date: 5/20/09 Workbook: AIMS_Shape_3.6 xlsm Technician: TEC Description: # % Cum. % # % Particles in Range 299 Low (260) 125 41.8% ( 260) 41.8% 3 2 0.7% Mode 175.6 2015 by the American Association of State Highway and Transport
42、ation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-12 AASHTO AIMS Sphericity Project Name: Coarse Aggregate Sample Date: 5/20/09 Workbook: AIMS_Shape_3.6 xlsm Technician: TEC Description: # % Cum. % # % Particles in Range 298 Low (0.3) 0 0.0% (0.3) 0.0% 3 0
43、 0.0% Mode 0.694 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-13 AASHTO AIMS Flat and Elongated Project Name: Coarse Aggregate Sample Date: 5/20/09 Workbook: AIMS_Shape_3.6 xlsm Technician
44、: TEC Description: F&E Sphericity F&E Sphericity F&E Sphericity Particles in Range 298 298 # % # % # % # % Average 2.481 0.669 L/S 1:1 298 100.0% Low (0.3) 0 0.0% 2:1 199 66.8% Medium (0.30.7) 180 60.4% 2 3:1 65 21.8% High (0.71.0) 118 39.6% 3 4:1 20 6.7% Out of Range 2 n 3 2 0.7% 0 0.0% L/S 5:1 2 0
45、.7% 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c TP 81-14 AASHTO AIMS Flat and Elongated Distribution Project Name: Coarse Aggregate Sample Date: 5/20/09 Workbook: AIMS_Shape_3.6 xlsm Technician
46、: TEC Description: F & E Ratio # Cum.% L/S 1:1 298 100.0% L/S 2:1 199 66.8% L/S 3:1 65 21.8% L/S 4:1 20 6.7% L/S 5:1 2 0.7% 1This provisional standard was first published in 2010. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
