1、 Standard Practice for Determining Aggregate Source Shape Values from Digital Image Analysis Shape Properties AASHTO Designation: PP 64-11 (2016)1 Release: Group 3 (August 2016) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.
2、C. 20001 TS-1c PP 64-1 AASHTO Standard Practice for Determining Aggregate Source Shape Values from Digital Image Analysis Shape Properties AASHTO Designation: PP 64-11 (2016)1Release: Group 3 (August 2016) 1. SCOPE 1.1. This standard covers the determination of aggregate source and source blend shap
3、e characteristics using gradation analysis and shape properties determined by means of digital image analysis. 1.2. This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the respon
4、sibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: T 11, Materials Finer Than 75-m (No. 200) Sieve in Mineral Aggregates by Washing T 27, Sie
5、ve Analysis of Fine and Coarse Aggregates T 84, Specific Gravity and Absorption of Fine Aggregate T 85, Specific Gravity and Absorption of Coarse Aggregate TP 81, Determining Aggregate Shape Properties by Means of Digital Image Analysis 2.2. Other Document: National Cooperative Highway Research Prog
6、ram Report 555, Test Methods for Characterizing Aggregate Shape, Texture, and Angularity 3. TERMINOLOGY 3.1. aggregate sizematerial retained on a given sieve size after passing the next larger sieve. 3.1.1. fine aggregateaggregate material passing 4.75-mm (No. 4) sieve. Sieve sizes are 2.36 mm (No.
7、8), 1.18 mm (No. 16), 0.60 mm (No. 30), 0.30 mm (No. 50), 0.15 mm (No. 100), and 0.075 mm (No. 200). 3.1.2. coarse aggregateaggregate material retained on 4.75-mm (No. 4) sieve. Sieve sizes are 25.0 mm (1 in.), 19.0 mm (3/4in.), 12.5 mm (1/2in.), 9.5 mm (3/8in.), and 4.75 mm (No. 4). 3.2. Shape Prop
8、erties for Each Retained Sieve (x): 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-2 AASHTO 3.2.1. gradient angularity (GA)applies to both fine and coarse aggregate sizes and is related to
9、the sharpness of the corners of two-dimensional images of aggregate particles. The gradient angularity quantifies changes along a particle boundary with higher gradient values indicating a more angular shape. Gradient angularity has a relative range of zero to 10,000, with a perfect circle having a
10、value of zero. Gradient angularity: 331113ni iiGAn+= (1) where: = angle of orientation 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 and describes the relativ
11、e smoothness or roughness of surface features less than approximately 0.5 mm in size that are too small to affect the overall shape. Texture has a relative scale of zero to 1000 with a smooth polished surface approaching a value of zero. ( )( )23,111,3Nn ijijTX D x yN= =(2) where: D = decomposition
12、function, n = decomposition level, N = total number of coefficients in an image, i = 1, 2, or 3 for 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-dimensio
13、nal shape of a particle. Sphericity has a relative scale of zero to one. A sphericity value of one indicates a particle has equal dimensions (cubical). 32ISLddSPd=(3) where: dS= particle shortest dimension, dI= particle intermediate dimension, and dL= particle longest dimension. Note 1The term “sphe
14、ricity” has been used for many years in research to describe this measurement. In principle, a cube does not have a sphericity of one because the diagonal is considered to be the longest dimension. A digital image acquisition and analysis system would measure a value of one for a cube because it wou
15、ld 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 aggregate particles. Form 2D has a relative scale of 0 to 20. A
16、perfect circle has a Form 2D value of zero. 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-3 AASHTO 360 0Form 2DRRR= +=(4) where: R= the radius of the particle at an angle of , and = the in
17、cremental difference in the angle. 3.2.5. flat and elongatedthose particles having a ratio of longest dimension to shortest dimension greater than a specified value. Aggregate particle dimensions in an x, y, z coordinate system: dS= particle shortest dimension, dI= particle intermediate, and dL= par
18、ticle longest dimension. Flatnessratio( / ):flatnessSIdSLd=(5) Elongationratio( / ):elongationILdILd=(6) Flatandelongatedvalue( therefore, actual mass is not required. 6.5. Calculate total particle surface area for each sieve size per sample unit mass: Particle surface area (each sieve x) (mm2): #x
19、xxSSA PSA P= (13) 6.6. Calculate sample surface area (per unit mass): 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-5 AASHTO 25.00.075Total surface area (mm ):xxTSA SSA=(14) 25.04.75Coarse
20、 surface area (mm ):xxCSA SSA=(15) 2.360.075Fine surface area (mm ):xxFSA SSA=(16) 6.7. Calculate sample particles count (per unit mass): 25.00.075Total particles:#xxTP P=(17) 25.04.75# Coarse particles: # #xxCP P=(18) 2.360.075# Fine particles:# #xxFP P=(19) 6.8. Calculate sample gradient angularit
21、y (weighted by surface area): 2.360.0751Fine gradient angularity:xxxFGA SSA GAFSA= (20) 25.04.751Coarse gradient angularity:xxxCGA SSA GACSA= (21) 25.00.0751Overall gradient angularity:xxxGA SSA GATSA= (22) 6.9. Calculate sample fine aggregate Form 2D (weighted by surface area): 2.360.075Form 2D12xx
22、xSSA DFSA= (23) 6.10. Calculate sample coarse aggregate texture (weighted by surface area): 25.04.751xxxTX SSA TXCSA= (24) 6.11. Calculate sample coarse aggregate sphericity (weighted by particle count): 25.04.751#xxxSP P SPCP= (25) 6.12. Calculate sample sphericity range distribution (weighted by p
23、article count): Percent of particles with sphericity 0.3: 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-6 AASHTO 25.04.751(0.3) # (0.3)#xxxSP P SPCP= (26) Percent of particles with spheric
24、ity 0.3 2:1, 3:1, 4:1, 5:1 % dL/dS 1: 25.04.75% % / ( 1)% / ( 1)100xxxR LSLS=(29) % dL/dS 2: 25.04.75% % / ( 2)% / ( 2)100xxxR LSLS=(30) % dL/dS 3: 25.04.75% % / ( 3)% / ( 3)100xxxR LSLS=(31) % dL/dS 4: 25.04.75% % / ( 4)% / ( 4)100xxxR LSLS=(32) % dL/dS 5: 25.04.75% % / ( 5)% / ( 5)100xxxR LSLS=(33
25、) 6.13.1. Calculate the sample weighted percentages of coarse aggregate flat or elongated values (weighted by mass fraction) at the following ratios: 1:1, 2:1, 3:1, 4:1, 5:1 % dI/dSor dL/dI 1: ( )( )25.04.75% % or ( 1)% or ( 1)100xxxR FEFE=(34) % dI/dSor dL/dI 2: ( )( )25.04.75% % or ( 2)% or ( 2)10
26、0xxxR FEFE=(35) % dI/dSor dL/dI 3: ( )( )25.04.75% % or ( 3)% or ( 3)100xxxR FEFE=(36) % dI/dSor dL/dI 4: ( )( )25.04.75% % or ( 4)% or ( 4)100xxxR FEFE=(37) % dI/dSor dL/dI 5: ( )( )25.04.75% % or ( 5)% or ( 5)100xxxR FEFE=(38) 2016 by the American Association of State Highway and Transportation Of
27、ficials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-7 AASHTO 7. CALCULATIONSMULTIPLE-SOURCE BLEND 7.1. Use the calculations in this section to estimate the shape characteristics of multiple-material source blends. Each source must be sampled and characterized accor
28、ding to Section 6 calculations. 7.2. Determine blend composition percentages: %ASn= percent aggregate source n (39) 1% 100niiAS=where: n = number of aggregate sources. 7.3. Calculate blend surface area: Blend total surface area (each sieve): 37.5Blend _1 0.075%100ni ixxixAS SSASSA= =(40) where: x =
29、0.075 to 25.0 mm, and n = number of aggregate sources. Total surface area blend (all sieves x = 0.075 to 25.0 mm) 25.0Blend Blend _0.075xxTSA SSA=(41) Coarse surface area blend (sieve x = 4.75 to 25.0): 25.0Blend Blend _4.75xxCSA SSA=(42) Fine surface area blend (sieve x =0.075 to 2.36): 2.36Blend B
30、lend _0.075xxFSA SSA=(43) 7.4. Calculate number of particles per blend unit mass for each sieve size: 25.0Blend _1 0.075%#100ni ixxixAS PP= =(44) 7.5. Calculate number of particles per blend unit mass: Total particle count blend: 25.0Blend Blend _0.075#xxTP P=(45) # Coarse particles blend: 2016 by t
31、he American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-8 AASHTO 25.0Blend Blend _4.75#xxCP P=(46) # Fine particles blend: 2.36Blend Blend _0.075#xxFP P=(47) 7.6. Calculate blend gradient angularity for each
32、 size x = 0.075 to 25.0 mm and combined (weighted by surface area): Blend _Blend _1%1100ii ix ixxxiAS SSA GAGASSA=(48) Blend fine gradient angularity: 2.36Blend Blend _ Blend _Blend0.0751xxxFGA SSA GAFSA= (49) Blend coarse gradient angularity: 25.0Blend Blend _ Blend _Blend4.751xxxCGA SSA GACSA= (50
33、) Blend overall gradient angularity: 25.0Blend Blend _ Blend _Blend0.0751xxxGA SSA GATSA= (51) 7.7. Calculate blend fine aggregate Form 2D for each sieve size x = 0.075 to 2.36 mm and combined (weighted by surface area): Blend _Blend _ 1%21Form 2D100ni ix ixxx iAS SSA DSSA=(52) Blend Form 2D: 2.36Bl
34、end Blend _ Blend _Blend 0.0751Form 2D 2xxxSSA DFSA=(53) 7.8. Calculate blend texture for each sieve size x = 4.75 to 25.0 mm and combined (weighted by coarse aggregate surface area): Blend _Blend _1%1100ni ix ixxxiAS SSA TXTXSSA=(54) Blend texture: 25.0Blend Blend _ Blend _Blend4.751xxxTX SSA TXCSA
35、= (55) 7.9. Calculate average blend sphericity for each sieve size x = 4.75 to 25.0 mm and blend (weighted by coarse particle count): 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-9 AASHTO
36、 Blend _Blend _ 1%#1# 100ni ix ixxx iAS P SPSPP=(56) Blend sphericity: 25.0Blend Blend _ Blend _Blend4.751#xxxSP P SPCP= (57) 7.10. Calculate blend sphericity distribution for each sieve size x = 4.75 to 25.0 mm and blend (weighted by coarse particle count): Percent of particles with sphericity 0.3
37、(Blend): Blend _Blend _1% # (0.3)1(0.3)100#ni ix ixxxiAS P SPSPP=(58) 25.0Blend Blend _ Blend _Blend4.751(0.3) # (0.3)#xxxSP P SPCP= (59) Percent of particles with sphericity 0.3 2 (Blend): Blend _21% % % / ( 2)% / ( 2)100ni ix ixxiAS R L SLS= (66) 2016 by the American Association of State Highway a
38、nd Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-10 AASHTO 25.0Blend Blend _4.75% / ( 2) % / ( 2)xxLS LS= (67) % dL/dS 3 (Blend): Blend _21% % % / ( 3)% / ( 3)100ni ix ixxiAS R L SLS= =(68) 25.0Blend Blend _4.75% / ( 3) % / ( 3)xxLS LS= (69)
39、% dL/dS 4 (Blend): Blend _21% % % / ( 4)% / ( 4)100ni ix ixxiAS R L SLS= =(70) 25.0Blend Blend _4.75% / ( 4) % / ( 4)xxLS LS= (71) % dL/dS 5 (Blend): Blend _21% % % / ( 5)% / ( 5)100ni ix ixxiAS R L SLS= =(72) 37.5Blend Blend _4.75% / ( 5) % / ( 5)xxLS LS= (73) 7.12. Calculate flat or elongated valu
40、es for each sieve size x = 4.75 to 25.0 mm and blend (weighted by mass fraction): % dI/dSor dL/dI 1 (Blend): ( )( )Blend _ 21% % % or ( 1)% or ( 1)100ni ix ixxiAS R F EFE= =(74) ( ) ( )25.0Blend Blend _4.75% or ( 1) % or ( 1)xxFE FE= (75)% dI/dSor dL/dI 2 (Blend): ( )( )Blend _ 21% % or ( 2)% or ( 2
41、)100ni ix ixxiAS R F EFE= =(76)( ) ( )25.0Blend Blend _4.75% or ( 2) % or ( 2)xxFE FE= (77)% dI/dSor dL/dI 3 (Blend): ( )( )Blend _21% % % or ( 3)% or ( 3)100ni ix ixxiAS R F EFE= =(78) ( ) ( )25.0Blend Blend _4.75% or ( 3) % or ( 3)xxFE FE= (79) 2016 by the American Association of State Highway and
42、 Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-11 AASHTO % dI/dSor dL/dI 4 (Blend): ( )( )Blend _21% % % or ( 4)% or ( 4)100ii ix ixxiAS R F EFE= =(80) ( ) ( )25.0Blend Blend _4.75% or ( 4) % or ( 4)xxFE FE= (81)% dI/dSor dL/dI 5 (Blend): ( )
43、( )Blend _21% % % or ( 5)% or ( 5)100ni ix ixxiAS R F EFE= =(82) ( ) ( )25.0Blend Blend _4.75% or ( 5) % or ( 5)xxFE FE= (83) 8. REPORT 8.1. Report the following information: 8.1.1. Project name; 8.1.2. Date of the analysis; 8.1.3. Material sample identifications: type, source, size, gradation; 8.1.
44、4. Number of particles analyzed for each size; and 8.1.5. Material shape property mean and standard deviation. Graphical representations of the property distributions may be included. 8.2. A sample report format is presented in Appendix X1. 9. PRECISION AND BIAS 9.1. PrecisionThis practice uses data
45、 generated from other testing methods to generate cumulative information; therefore, the precision of the values generated in this practice are established by the precision of the standards used to collect the raw data. 9.2. BiasThe research required to determine the bias of this procedure has not b
46、een conducted. 10. KEYWORDS 10.1. Aggregate; angularity; consensus property; elongation; form; shape; texture. 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-12 AASHTO APPENDIX (Nonmandator
47、y Information) X1. SAMPLE REPORT 2016 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1c PP 64-13 AASHTO AIMS Stockpile Summary Project Name: 41_Granite_1 Date: 2/5/09 Workbook: 41_Granite_AIMS_Stockpile_v3.6.xlsm Technician: mjg Description: Combined Properties (weighted) Flat and Elongated Ratio (Coarse) Flat and Elongated Ratio (Coarse) 2D Form (Fine) 7.95 Sphericity (Coarse) % % Cum % Angularity (Coarse & Fine) 3457.5 Low (0.3) 0.0% L/S 1:1 65.0% F or E 1:1 65.0% Fine Angularity 3501.3 Mediu
