Application of LADAR in the Analysis of Aggregate Characteristics (2012)

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55 In this chapter, comparisons of the aggregate dimensions using the FTI system and manual measurement will first be discussed for the coarse aggregates in Set 1. The relationship between the FTI calculated dimensions and the manually measured dimensions can be followed with a linear regres- sion, indicating the accuracy of the FTI system. To verify the reliability of the FTI system, all the coarse aggregates in Set 1 are imaged and analyzed using the FTI, AIMS II, and UIAIA systems to compare the angularity and texture results. To eval- uate the sensitivity of the FTI system, the abrasion effect of the Micro-Deval test on aggregates is detected by comparing the changes of angularity and texture before and after the Micro- Deval test for coarse aggregates in Set 2. Furthermore, fine aggregates are evaluated using both the FTI system and AIMS II system to discuss the reliability of the FTI system in the analysis of fine aggregates with the comparison of angularity rankings using both the FTI and AIMS II systems. After the validation of the capability of the FTI system to analyze both coarse and fine aggregates, the FTI analysis results of rounded glacial gravel aggregates and crushed glacial gravel aggregates are compared to assess the crushing effects on aggregates. In the end, the FTI system features are compared to those of the other aggregate imaging systems, such as AIMS II and UIAIA. 6.1 Comparison Between the FTI Results and Manual Measurements Figure 6-1 through Figure 6-4 present the relationship between the sphericity obtained by the FTI system and the sphericity calculated from manually measured dimensions (hereinafter referred to as manually measured sphericity) for ¾-in., ½-in., 3/8-in., and #4 aggregates in Set 1, respec- tively. The manually measured sphericity is labeled x, and the sphericity acquired from the FTI system is labeled y for the same aggregate particle. The relationship between x and y is obtained through linear regressions. Similar linear relation- ships can also be found between the results by FTI and those via manual measurements for flatness ratio, elongation ratio, and FE ratio. The good agreement between the FTI results and the manually measured results has validated the capabil- ity of the FTI system to characterize the shape of aggregates. 6.2 Angularity and Texture Comparison of the FTI Results to AIMS II and UIAIA Results To further evaluate the soundness of the FTI system, all the ¾-in. aggregate particles of the seven types of aggregate were also assessed using AIMS II and UIAIA. Appendix F presents the photographs of the ¾-in. aggregates. Via visual judgment, one can observe that blast furnace slag has very angular and the roughest surfaces, and that rounded glacial gravel is the least angular and has very smooth surfaces. Table 6-1 shows the angularity and texture rankings accord- ing to the mean values of the FTI, AIMS II, and UIAIA angular- ity and texture measurements of aggregates in Set 1. In general, blast furnace slag aggregates are the most angular, with rougher surfaces among the seven types of aggregate; rounded glacial gravel aggregates were found to have the smoothest surfaces. Further details can be found in Table 6-2 through Table 6-5. In terms of FTI results, both blast furnace slag and cop- per ore have large values for angularity and texture for the ¾-in. aggregates, indicating angular aggregates with very rough surfaces. Conversely, compared with other aggregates, rounded glacial gravel, iron ore, and limestone have smooth surfaces with smaller angularity. Of the ½-in. aggregates, blast furnace slag and crushed glacial gravel aggregates are the most angular, whereas rounded glacial gravel and dolomite are the least angular. In terms of texture, blast furnace slag and copper ore are the roughest aggregates, and rounded gla- cial gravel aggregates are the smoothest. For 3/8-in. aggregates, iron ore is the most angular aggregate instead of blast furnace slag. Of the #4 aggregates, copper ore is the most angular with C h a p t e r 6 Discussion

56 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 BFS 3/8'' CO 3/8'' DLT 3/8'' GGC 3/8'' GGR 3/8'' IO 3/8'' LST 3/8'' FT I S ph er ic ity Manual Measured Sphericity Regression lines BFS 3/8'' y = 0.6442x + 0.2607, R2 = 0.8751 CO 3/8'' y = 0.7522x + 0.2161, R2 = 0.9108 DLT 3/8'' y = 0.7501x + 0.2313, R2 = 0.9448 GGC 3/8'' y = 0.7068x + 0.298, R2 = 0.8916 GGR 3/8'' y = 0.8665x + 0.1754, R2 = 0.9271 IO 3/8'' y = 1.1001x - 0.0721, R2 = 0.9675 LST 3/8'' y = 1.118x - 0.0507, R2 = 0.9097 Figure 6-3. FTI sphericity versus manually measured sphericity for 3⁄8-in. aggregates. 0.2 0 .4 0.6 0 .8 0.2 0.4 0.6 0.8 1.0 BFS 1/2'' CO 1/2'' DLT 1/2'' GGC 1/2'' GGR 1/2'' IO 1/2'' LST 1/2'' FT I S ph er ic ity Manual Measured Sphericity Regression lines BFS 1/2'' y = 1.0373x - 0.0228, R2 = 0.977 CO 1/2'' y = 1.0697x - 0.0402, R2 = 0.9558 DLT 1/2'' y = 0.925x + 0.0571, R2 = 0.9756 GGC 1/2'' y = 1.1481x - 0.078, R2 = 0.9521 GGR 1/2'' y = 0.9379x + 0.0248, R2 = 0.9079 IO 1/2'' y = 1.2468x - 0.1135, R2 = 0.8965 LST 1/2'' y = 0.8096x + 0.119, R2 = 0.9556 Figure 6-2. FTI sphericity versus manually measured sphericity for ½-in. aggregates. 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 BFS 3/4'' CO 3/4'' DLT 3/4'' GGC 3/4'' GGR 3/4'' IO 3/4'' LST 3/4'' FT I S ph er ic ity Manual Measured Sphericity Regression lines BFS 3/4'' y = 1.0199x - 0.0881, R2 = 0.9547 CO 3/4'' y = 1.2136x - 0.2041, R2 = 0.9664 DLT 3/4'' y = 0.745x + 0.1398, R2 = 0.9094 GGC 3/4'' y = 1.0346x - 0.068, R2 = 0.922 GGR 3/4'' y = 0.994x - 0.0863, R2 = 0.8841 IO 3/4'' y = 0.7489x + 0.1508, R2 = 0.9552 LST 3/4'' y = 1.3307x - 0.2432, R2 = 0.932 Figure 6-1. FTI sphericity versus manually measured sphericity for ¾-in. aggregates.

57 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 BFS #4 CO #4 DLT #4 GGC #4 GGR #4 IO #4 LST #4 FT I S ph er ic ity Manual Measured Sphericity Regression lines BFS #4 y = 1.1879x - 0.1369, R2 = 0.962 CO #4 y = 1.19x - 0.0842, R2 = 0.9569 DLT #4 y = 0.7776x + 0.0987, R2 = 0.9571 GGC #4 y = 1.1713x - 0.1089, R2 = 0.9111 GGR #4 y = 1.1262x - 0.0953, R2 = 0.9336 IO #4 y = 0.7615x + 0.1254, R2 = 0.8825 LST #4 y = 1.1494x - 0.0715, R2 = 0.9353 Figure 6-4. FTI sphericity versus manually measured sphericity for #4 aggregates. Aggregate S ize 3/4 ” 1/2 ” 3/8 ” #4 Roughness R anking Morphological C haracteristics Ang Tex Ang Tex Ang Tex Ang Tex FTI BFS BFS BFS BFS IO IO CO CO Rough CO CO GGC CO LST LST IO LST GGC DLT LST DLT BFS BFS BFS DLT DLT GGC IO GGC GGC GGC DLT IO ↓ IO LST CO IO CO GGR LST BFS LST IO GGR LST GGR CO GGC GGR GGR GGR DLT GGR DLT DLT GGR GGC Smooth AIMS II CO CO IO BFS CO BFS CO BFS Rough IO IO BFS CO IO DLT IO CO BFS DLT CO GGC BFS LST LST LST DLT BFS LST LST LST CO GGC GGC ↓ LST LST DLT DLT DLT IO BFS IO GGC GGC GGC IO GGC GGC DLT DLT GGR GGR GGR GGR GGR GGR GGR GGR Smooth UIAIA* GGC GGC GGC GGC GGC GGC BFS CO Rough BFS BFS CO CO CO CO CO GGR CO DLT LST BFS BFS DLT GGR GGC ↓ LST GGR BFS DLT LST LST LST DLT DLT CO DLT LST DLT GGR DLT LST GGR LST GGR GGR GGR BFS GGC BFS Smooth *U IAIA is incapable of analyz ing iron ore aggregates because the color of iron ore aggregates is very similar to the background color of the UIAIA conveyor. Note: Ang = Angularity; Tex = Texture; BFS = Blast f urnace s lag; CO = Copper o re; DLT = Dolomite; GG C = Glacial g ravel – c rushed; GGR = Glacial g ravel – r ounded; IO = Iron o re ; LST = Limestone. Table 6-1. Roughness ranking results in the FTI, AIMS II, and UIAIA systems.

58 1/2” Aggregates Blast Furnace Slag Copper Ore Dolomite Glacial Gravel – Crushed Glacial Gravel – Rounded Iron Ore Limestone Angularity FTI Mean 2.44 × 10 0.98 × 10 0.60 × 10 1.46 × 10 0.97 × 10 1.00 × 10 1.90 × 10 Standard deviation 5.18 × 10 1.14 × 10 1.13 × 10 2.51 × 10 1.11 × 10 1.04 × 10 4.54 × 10 AIMS II Mean 3040.72 3126.44 2864.42 2650.92 1362.78 2932.80 2859.35 Standard deviation 833.09 604.35 697.83 612.77 624.87 515.95 631.80 UIAIA Mean 367.51 394.23 333.59 458.09 239.89 – 357.07 Standard deviation 80.71 77 55.15 108.54 83.19 – 51.69 Texture FTI Mean 9.57 × 10 4.69 × 10 2.86 × 10 2.70 × 10 3.54 × 10 5.17 × 10 4.60 × 10 Standard deviation 13.70 × 10 5.68 × 10 5.18 × 10 3.37 × 10 4.32 × 10 6.47 × 10 8.38 × 10 -4 -4 -4 -4 -4 -4 -6 -6 -6 -6 -6 -6 -6 -4 -4 -4 -4 -4 -4 -4 -4 -6 -6 -6 -6 -6 -6 -6 AIMS II Mean 574.74 365.75 259.11 322.72 217.55 243.40 270.21 Standard deviation 155.81 120.04 113.33 188.26 145.06 112.90 122.26 UIAIA Mean 1.12 1.19 0.92 2.15 1.00 – 0.91 Standard deviation 0.39 0.44 0.39 0.98 0.76 – 0.27 Table 6-3. Angularity and texture using FTI, AIMS II, and UIAIA for ½-in. aggregates. 3/4” Aggregates Blast Furnace Slag Copper Ore Dolomite Glacial Gravel – Crushed Glacial Gravel – Rounded Iron Ore Limestone Angularity FTI Mean 2.74 × 10-4 2.69 × 10-4 1.58 × 10-42.31 × 10-4 0.84 × 10-4 1.01 × 10-4 0.99 × 10-4 Standard deviation 6.59 × 10-4 4.52 × 10-4 3.07 × 10-44.25 × 10-4 1.13 × 10-4 1.12 × 10-4 1.39 × 10-4 AIMS II Mean 2968.15 3138.48 2689.25 2590.37 1532.39 3160.48 2757.89 Standard deviation 930.95 625.82 690.57 736.76 660.06 722.55 761.4 UIAIA Mean 439.24 373.62 337.34 486.73 254.01 – 348.93 Standard deviation 115 76.26 62.38 110.12 84.35 – 59.11 Texture FTI Mean 6.38 × 10-6 4.97 × 10-6 3.90 × 10-63.86 × 10-6 1.60 × 10-6 2.13 × 10-6 2.52 × 10-6 Standard deviation 6.28 × 10-6 4.49 × 10-6 3.93 × 10-65.54 × 10-6 1.66 × 10-6 1.93 × 10-6 2.74 × 10-6 AIMS II Mean 503.65 334.79 254.41 379.34 161.95 201.34 294.77 Standard deviation 181.8 118.19 117.84 152.53 97.89 80.18 103.36 UIAIA Mean 1.69 0.95 1.09 2.09 0.98 – 0.82 Standard deviation 1.18 0.28 0.84 0.73 0.55 – 0.25 Table 6-2. Angularity and texture using FTI, AIMS II, and UIAIA for ¾-in. aggregates.

59 3/8” Aggregates Blast Furnace Slag Copper Ore Dolomite Glacial Gravel – Crushed Glacial Gravel – Rounded Iron Ore Limestone Angularity FTI Mean 2.19 × 10-4 0.75 × 10-4 0.87 × 10-4 1.47 × 10-4 1.09 × 10-4 10.9 × 10-4 3.32 × 10-4 Standard deviation 4.48 × 10-4 1.09 × 10-4 0.97 × 10-4 1.98 × 10-4 1.94 × 10-4 23.6 × 10-4 6.33 × 10-4 AIMS II Mean 3005.16 3276.11 2675.33 2621.36 1294.42 1625.2 2745.29 Standard deviation 551.28 815.64 632.1 756.18 839.81 625.31 559.12 UIAIA Mean 339.55 359.97 324.19 447.43 258.84 – 343.73 Standard deviation 51.31 78.38 59.69 85.5 92.44 – 50.22 Texture FTI Mean 9.48 × 10-6 3.84 × 10-6 3.59 × 10-6 6.94 × 10-6 4.81 × 10-6 80.3 × 10-6 15.9 × 10-6 Standard deviation 11.8 × 10-6 6.19 × 10-6 3.92 × 10-6 10.0 × 10-6 15.5 × 10-6 304.0 × 10-6 32.6 × 10-6 AIMS II Mean 538.94 339.83 239.18 273.31 169.35 154.43 258.47 Standard deviation 137.83 113.31 100.19 140.35 82.29 123.2 100.65 UIAIA Mean 0.86 1.42 1.14 1.66 0.92 – 0.95 Standard deviation 0.27 0.67 0.46 0.69 0.53 – 0.39 Table 6-4. Angularity and texture using FTI, AIMS II, and UIAIA for 3⁄8-in. aggregates. #4 Aggregates Blast Furnace Slag Copper Ore Dolomite Glacial Gravel – Crushed Glacial Gavel – Rounded Iron Ore Limestone Angularity FTI Mean 14.7 × 10 42.5 × 10 15.7 × 10 2.48 × 10 2.48 × 10 21.6 × 10 12.5 × 10 Standard deviation 49.9 × 10 74.4 × 10 20.5 × 10 2.66 × 10 2.04 × 10 29.6 × 10 20.6 × 10 AIMS II Mean 3336.79 3450.46 2920.58 3023.80 1563.85 3183.12 2999.47 Standard deviation 897.00 809.55 710.91 661.65 1134.25 627.50 525.94 UIAIA Mean 400.65 407.43 325.72 483.91 359.51 – 335.80 Standard deviation 82.65 76.82 56.16 93.24 110.88 – 60.30 Texture FTI Mean 60 × 10 190 × 10 82.3 × 10 9.33 × 10 14.4 × 10 74.2 × 10 91.8 × 10 Standard deviation 149 × 10 512 × 10 224 × 10 16.4 × 10 15.4 × 10 86.3 × 10 203 × 10 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -6 -6 -6 -6 -6 -6 -6 -6 -6 -6 -6 -6 -6 -6 AIMS II Mean 491.31 331.60 159.75 240.34 132.07 208.52 290.37 Standard deviation 130.03 77.46 66.15 135.65 109.45 75.86 116.40 UIAIA Mean 0.97 1.66 1.22 2.24 1.35 – 1.16 Standard deviation 0.33 0.81 0.77 1.07 0.95 – 0.67 Table 6-5. Angularity and texture using FTI, AIMS II, and UIAIA for # 4 aggregates.

60 the roughest surfaces, whereas crushed glacial gravel and rounded glacial gravel are less angular aggregates with the smoothest surfaces. In terms of the AIMS II results, rounded glacial gravel aggre- gates have the smallest angularity index, corresponding to the smoothest surfaces with least angularity, of all the aggregates. For the ¾-in. aggregates, copper ore is the most angular with the roughest surfaces, followed by iron ore; rounded glacial gravel is the least angular with the smoothest surfaces, fol- lowed by crushed glacial gravel and limestone. For ½-in. aggregates, iron ore aggregates are the most angular, followed by blast furnace slag and copper ore, whereas iron ore has very smooth surfaces in terms of texture. For 3/8-in. aggre- gates, copper ore is the most angular with intermediate surface texture, and blast furnace slag is the third most angular with the roughest surfaces. Among #4 aggregates, copper ore has the greatest value of angularity with the second roughest surfaces, and blast furnace slag is much less angular with the roughest surfaces. The UIAIA is incapable of imaging iron ore aggregates because the color of iron ore aggregates is very similar to the background color of the UIAIA conveyor. Therefore, there is no result for iron ore by UIAIA. By UIAIA, among all the ¾-in., ½-in., and 3/8-in. aggregates, crushed glacial gravel is the most angular with the roughest surfaces, followed by either blast fur- nace slag or copper ore; rounded glacial gravel is the least angu- lar aggregate. For #4 aggregates, blast furnace slag is the most angular with the smoothest surfaces. Copper ore is the second most angular, with the roughest surfaces. Table 6-2 shows the mean values and the standard devia- tions for the seven aggregates using the FTI, AIMS II, and UIAIA systems. Regardless of the different definitions of mor- phological descriptors, the results from the three aggregate imaging systems indicate that blast furnace slag has very angular and rough surfaces and that rounded glacial gravel has the least angular and smooth surfaces. For ¾-in. aggre- gates, the average FTI angularity indices of blast furnace slag and copper ore are 2.74 × 10-4 and 2.69 × 10-4, respectively; the average FTI texture index is 6.38 × 10-6 for blast furnace slag and 4.97 × 10-6 for copper ore. Both blast furnace slag and copper ore have large values of angularity and texture, indicating angular and rough surfaces, followed by crushed glacial gravel and dolomite. Conversely, rounded glacial gravel, iron ore, and limestone have smooth surfaces with less angu- larity compared to the other aggregates. From the AIMS II results for ¾-in. aggregates, rounded glacial gravel has the smallest values of angularity (1532.29) and texture (161.95), indicating the smoothest surfaces with the least angularity. Copper ore has the most angular and roughest surface, followed by iron ore; rounded glacial gravel has the least angular and the smoothest surface, followed by crushed glacial gravel and limestone. Iron ore aggregates cannot be imaged in UIAIA because the color of iron ore aggregates is very similar to the color of the UIAIA conveyor. Of the ¾-in. aggregates assessed, crushed glacial gravel is the most angular and has the roughest surfaces, followed by blast furnace slag, which is inconsistent with the rankings based on the results by FTI and AIMS II. Since it is impossible to compare results of different meth- ods due to their different definitions, relative rankings may provide a convenient comparison. Figure 6-5 plots the angu- larity and texture rankings for the ¾-in. aggregates. All the data in this figure are generated from Table 6-2 by divid- ing the mean value of each category (aggregate type and method, total of 4 × 7 - 1 = 27 combinations; iron ore cannot be imaged by UIAIA system) by the smallest mean of either angularity or texture in that category. For example, the FTI angularity ranking for BFS ¾-in. aggregates is 3.262, divid- ing the mean value of the BFS FTI angularity 2.74 × 10-4 by the minimum mean value of the FTI angularity among seven types of ¾-in. aggregates, which is 0.84 × 10-4. As shown in Figure 6-5, the FTI, AIMS II, and UIAIA roughness rankings are consistent in that the rounded glacial gravel aggregates are the least angular and smooth, and the BFS aggregates are very angular and rough. The roughness rankings by these methods are typically consistent with visual judgments from the photographs in Appendix E. Table 6-3 shows the mean values and standard deviations for seven types of ½-in. aggregates. Using the same angular- ity and texture ranking method, the angularity and texture rankings for ½-in. aggregates are plotted in Figure 6-6 based on the mean values in Table 6-3. According to the FTI rank- ing, blast furnace slag aggregates are the most angular, with 0 1 2 3 4 5 1=Smooth, 5=Rough FTI AIMSII UIAIA A ng ul ar ity ra nk in g FTI AIMSII UIAIA 1=Least angular, 5=Most angular 0 1 2 3 4 5 BFS CO DLT GGC GGR IO LST Te xt ur e ra nk in g Note: BFS=Blast furnace slag; CO=Copper ore; DLT=Dolomite; GGC=Glacial gravel crushed; GGR=Glacial gravel rounded; IO=Iron ore; LST=limestone. Figure 6-5. Roughness ranking of ¾-in. aggregates using the FTI, AIMS II, and UIAIA systems.

61 0 5 10 15 20 25 3/8'' Aggregates in Aggregate set 1 1=Smooth, 25=Rough FTI AIMSII UIAIA A ng ul ar ity ra nk in g FTI AIMSII UIAIA 1=Least angular, 25=Most angular 0 5 10 15 20 25 BFS CO DLT GGC GGR IO LST Te xt ur e ra nk in g Note: BFS=Blast furnace slag; CO=Copper ore; DLT=Dolomite; GGC=Glacial gravel crushed; GGR=Glacial gravel rounded; IO=Iron ore; LST=Limestone. Figure 6-7. Roughness ranking of 3⁄8-in. aggregates using the FTI, AIMS II, and UIAIA systems. 0 5 10 15 20 25 1=Smooth, 25=Rough FTI AIMSII UIAIA A ng ul ar ity ra nk in g FTI AIMSII UIAIA 1=Least angular, 25=Most angular 0 5 10 15 20 25 BFS CO DLT GGC GGR IO LST Te xt ur e ra nk in g Note: BFS=Blast furnace slag; CO=Copper ore; DLT=Dolomite; GGC=Glacial gravel crushed; GGR=Glacial gravel rounded; IO=Iron ore; LST=Limestone. #4 Aggregates in Aggregate set 1 Figure 6-8. Roughness ranking of #4 aggregates using the FTI, AIMS II, and UIAIA systems. 0 1 2 3 4 5 1/2'' Aggregates in Aggregate set 1 1=Smooth, 5=Rough FTI AIMSII UIAIA A ng ul ar ity ra nk in g FTI AIMSII UIAIA 1=Least angular, 5=Most angular 0 1 2 3 4 5 BFS CO DLT GGC GGR IO LST Te xt ur e ra nk in g Note: BFS=Blast furnace slag; CO=Copper ore; DLT=Dolomite; GGC=Glacial gravel crushed; GGR=Glacial gravel rounded; IO=Iron ore; LST=Limestone. Figure 6-6. Roughness ranking of ½-in. aggregates using the FTI, AIMS II, and UIAIA systems. the roughest surfaces, followed by crushed glacial gravel as the second most angular and the fourth roughest surfaces. Rounded glacial gravel is the second least angular aggregate with the smoothest surfaces. According to the AIMS II rank- ing, copper ore is the most angular with the second roughest surfaces, followed by blast furnace slag as the second most angular with the roughest surfaces. Rounded glacial gravel is the least angular with the smoothest surfaces. In the UIAIA ranking, rounded glacial gravel aggregates are the second most angular with the smoothest surfaces, and crushed gla- cial gravel is the most angular with the roughest surfaces. Table 6-4 and Table 6-5 show the mean values and stan- dard deviations for the seven 3/8-in. and #4 aggregates. Fig- ure 6-7 and Figure 6-8 plot the roughness rankings of these aggregates using the results of the FTI, AIMS II, and UIAIA systems. The three aggregate imaging techniques are in agreement that blast furnace slag, crushed glacial gravel, and copper ore are very angular aggregates with very rough surfaces, and rounded glacial gravel aggregates are the least angu- lar with the smoothest surfaces. Obviously the three image analysis techniques could not give the same rankings of angularity and texture. Possible reasons include: (1) dif- ferent definitions of angularity and texture by the three techniques, and (2) different image resolutions in the three aggregate imaging systems. An advantage of using the FTI system is that it reconstructs the real 3-D coordinates of aggregate surfaces and performs morphological character- ization based on the real 3-D coordinates, which makes it possible to assess the real 3-D morphological characteris- tics of the aggregates. 6.3 Assessments of Sensitivity of Angularity and Texture Change The FTI system was used to measure the angularity and texture of 20 coarse aggregates in Set 2 before and after the Micro-Deval test to assess the sensitivity of the FTI system to detect changes in the morphological characteristics of the aggregates due to abrasion. The changes of FTI angularity and texture are shown in Figure 6-9. In this figure, the per- centage change denotes the difference in either angularity

62 or texture of an aggregate before and after the Micro-Deval test, divided by the angularity and texture of the aggregates before testing. Figure 6-9(a) shows the change of both angularity and tex- ture after the Micro-Deval test for 15 min. A negative change in angularity indicates that an aggregate became less angular after the Micro-Deval test. A positive change in texture means that the aggregates became rougher. Strasburg experiences the greatest change compared to the other three types of aggre- gate. The general trend shown in this figure is that most of the aggregates become less angular, as expected. However, there is an increase in angularity for Broadway aggregates. Pos- sible reasons could be that the Micro-Deval test causes some breakage in this type of aggregate, resulting in larger angu- larity. The increase in texture could be due to the increase of textured surfaces when aggregates were crushed. Figure 6-9(b) shows the change in both angularity and texture after the Micro-Deval test for 45 min. Different from results after Micro-Deval testing for 15 min., three of the four types of aggregate become more angular, denoted by a positive change in angularity. Both Maymead and Salem aggregates experienced more than a 60% increase in angu- larity, indicating that aggregate particles experienced break- age. Conversely, the Strasburg aggregate exhibits about a 5% decrease in angularity, which is most likely attributed to the abrasion of the sharp corners of the surfaces. The decrease in angularity may be interpreted as that the loss of angular elements is larger than the angular elements produced by breakage due to abrasion. In terms of texture, there are dramatic increases for Broadway, Maymead, and Salem aggregates. However, Strasburg aggregates expe- rienced a 28% decrease in texture due to abrasion in the Micro-Deval test for 45 min. The results show the incon- sistency in change of angularity and texture as indicated by other tests. The changes of FTI angularity and texture mean values during the Micro-Deval test process indicate that the Micro- Deval test might change the angularity and texture proper- ties of aggregates. However, it is suggested to analyze more aggregates to reach a persuasive conclusion, since the ANOVA test suggests that the sample population of coarse aggregates in Set 2 is not large enough to indicate that the duration of the Micro-Deval test has an effect on the FTI angularity and texture (Section 5.1.2). 6.4 Comparison of Angularity for Fine Aggregates Between the FTI and AIMS II Results To evaluate the capability of the FTI system to analyze fine aggregates, two types of fine aggregates are imaged and compared to the AIMS II angularity results: fine aggregates passing on a #4 sieve and retaining on a #8 sieve (here- inafter referred to as #8 aggregates), and fine aggregates passing on a #8 sieve and retaining on a #16 sieve (here- inafter referred to as #16 aggregates). There are six types of #8 aggregate and five types of #16 aggregate. All the fine aggregates have the same origins and physical properties as the corresponding types of coarse aggregate in Set 1 (Table 4-4). More than 100 fine aggregates are analyzed for each aggregate size. It is worth noting that the morphological properties to describe morphological characteristics of fine aggregates in the FTI system include sphericity, flatness ratio, elongation ratio, and angularity. The value of sphericity ranges from 0 to 1; a sphericity value of 1 indicates a particle with equal dimensions. Conversely, the morphological properties used in AIMS II are Form 2-D and angularity. The index of Form 2-D is defined by Eq. 6-1. Form 2-D ranges from 0 to 20, -40 -30 -20 -10 0 10 20 30 40 StrasburgSalemMaymead Pe rc en ta ge o f c ha ng e (% ) After 15 minutes of Micro-Deval Angularity Texture Broadway (a) After the Micro-Deval test for 15 min. -200 -100 0 100 200 300 Pe rc en ta ge o f c ha ng e (% ) StrasburgSalemMaymeadBroadway After 45 minutes of Micro-Deval Angularity Texture (b) After the Micro-Deval test for 45 min. Figure 6-9. FTI results change.

63 BFS CO DLT GGC GGR 0 1 2 3 4 5 A ng ul ar ity ra nk in g FTI #16 AIMS II #16 Note: BFS=Blast furnace slag; CO=Copper ore; DLT=Dolomite; GGC=Glacial gravel crushed; GGR=Glacial gravel rounded. Figure 6-11. Angularity ranking of the FTI and AIMS II results for #16 aggregates. BFS CO DLT GGC GGR LST 0 1 2 3 4 5 Note: BFS=Blast furnace slag; CO=Copper ore; DLT=Dolomite; GGC=Glacial gravel crushed; GGR=Glacial gravel rounded; LST=Limestone. A ng ul ar ity ra nk in g FTI #8 AIMS II #8 Figure 6-10. Angularity ranking of the FTI and AIMS II results for #8 aggregates. #8 FTI AIMS II #16 FTI AIMS II BFS 0.0350 4020.38 BFS 0.0560 4160.08 CO 0.0210 3801.85 CO 0.0499 3592.75 DLT 0.0148 3530.48 DLT 0.0423 3678.60 GGC 0.0241 3565.02 GGC 0.0554 3425.95 GGR 0.0222 2261.61 GGR 0.0421 2555.49 LST 0.0280 2874.60 Table 6-6. Mean values of the FTI angularity and AIMS II angularity. with a Form 2-D value of 0 for a perfect circle. Therefore, only angularity is compared between the FTI results and AIMS II results. Table 6-6 shows the angularity rankings according to the mean values of the FTI and AIMS II angu- larity results for fine aggregates. Form D R R R 2 0 360 = −    +∆ = −∆ ∑ θ θ θ θθ θ Eq. 6-1 where Rq is the radius of the particle at angle q, and Dq is the incremental difference in the angle. Figure 6-10 plots the angularity rankings of the FTI results and AIMS II results for #8 aggregates. The ranking values in this figure are calculated from Table 6-6 by dividing the mean value of each aggregate type by the minimum mean value for all types of #8 aggregates. For example, the FTI angularity ranking value of blast furnace slag #8 aggregates is obtained by dividing its mean FTI angularity of 0.350 by the minimum mean FTI angularity of 0.0148 for all #8 aggregates. For the six types of #8 aggregate, the FTI and AIMS II systems agree that blast furnace slag is the most angular; dolomite and rounded glacial gravel aggregates are the least angular. Figure 6-11 plots the angularity ranking of the FTI results and AIMS II results for #16 aggregates. The ranking values in this figure are the result of dividing the mean value of each aggregate type by the minimum mean value for all types of #16 aggregate. The FTI system and AIMS II agree that blast furnace slag has the most angular aggregates, and rounded glacial gravel has the smoothest aggregates of the five types of aggregates. Copper ore and crushed glacial gravel have very close angularity values using both the FTI system and AIMS II. 6.5 Crushing Effect on Aggregate Morphological Characteristics Using the FTI system There are two types of glacial gravel aggregate of the same origin: rounded glacial gravel as natural aggregates and crushed glacial gravel as crushed aggregates. To study the effect of crushing, the FTI results of both fine and coarse glacial gravel aggregates are presented in Table 6-7. They include the average values and standard deviations of sphe- ricity, flatness ratio, elongation ratio, angularity, and texture for GGR and GGC aggregates. The sizes of GGR and GGC aggregates vary from ¾ in. to #16. To study the crushing effect on the morphological properties of aggregates, the distributions of morphological properties of both coarse and fine GGR and GGC aggregates are presented in Fig- ure 6-12 through Figure 6-20.

64 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) Sphericity Glacial Gravel Crushed 3/4'' Glacial Gravel Crushed 1/2'' Glacial Gravel Crushed 3/8'' Glacial Gravel Crushed #4 Glacial Gravel Rounded 3/4'' Glacial Gravel Rounded 1/2'' Glacial Gravel Rounded 3/8'' Glacial Gravel Rounded #4 Figure 6-12. Effect of crushing on the FTI sphericity results of coarse aggregates. 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) Flatness ratio Glacial Gravel Crushed 3/4'' Glacial Gravel Crushed 1/2'' Glacial Gravel Crushed 3/8'' Glacial Gravel Crushed #4 Glacial Gravel Rounded 3/4'' Glacial Gravel Rounded 1/2'' Glacial Gravel Rounded 3/8'' Glacial Gravel Rounded #4 Figure 6-13. Effect of crushing on the FTI flatness ratio results of coarse aggregates. Aggregate Size 3/4” 1/2” 3/8” #4 #8 #16 Sphericity GGR Average 0.68 0.70 0.79 0.73 0.53 0.39 Standard deviation 0.09 0.06 0.12 0.11 0.12 0.14 GGC Average 0.74 0.74 0.79 0.69 0.58 0.30 Standard deviation 0.10 0.09 0.06 0.13 0.16 0.10 Flatness ratio GGR Average 0.59 0.71 0.78 0.77 0.58 0.63 Standard deviation 0.17 0.16 0.17 0.25 0.21 0.22 GGC Average 0.71 0.77 0.80 0.71 0.70 0.60 Standard deviation 0.17 0.15 0.13 0.16 0.21 0.16 Elongation ratio GGR Average 0.75 0.71 0.80 0.73 0.54 0.32 Standard deviation 0.11 0.11 0.14 0.18 0.21 0.14 GGC Average 0.77 0.74 0.80 0.69 0.55 0.22 Standard deviation 0.12 0.12 0.11 0.16 0.22 0.11 Angularity GGR Average 8.44 × 10-5 9.71 × 10-5 1.09 × 10-5 2.48 × 10-5 2.22 × 10-2 4.21 × 10-2 Standard deviation 1.13 × 10-4 1.11 × 10-4 1.94 × 10-4 2.04 × 10-4 1.48 × 10-2 2.49 × 10-2 GGC Average 2.31 × 10-4 1.46 × 10-4 1.47 × 10-4 2.48 × 10-4 2.41 × 10-2 5.54 × 10-2 Standard deviation 4.25 × 10-4 2.51 × 10-4 1.98 × 10-4 2.66 × 10-4 1.49 × 10-2 1.87 × 10-2 Texture GGR Average 1.60 × 10-6 3.54 × 10-6 4.81 × 10-6 1.44 × 10-5 – – Standard deviation 1.66 × 10-6 4.32 × 10-6 1.54 × 10-5 1.54 × 10-5 – – GGC Average 3.86 × 10-6 2.69 × 10-6 6.94 × 10-6 9.33 × 10-6 – – Standard deviation 5.54 × 10-6 3.37 × 10-6 1.00 × 10-5 1.64 × 10-5 – – Table 6-7. FTI angularity and texture results of GGR and GGC aggregates.

65 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) Elongation ratio Glacial Gravel Crushed 3/4'' Glacial Gravel Crushed 1/2'' Glacial Gravel Crushed 3/8'' Glacial Gravel Crushed #4 Glacial Gravel Rounded 3/4'' Glacial Gravel Rounded 1/2'' Glacial Gravel Rounded 3/8'' Glacial Gravel Rounded #4 Figure 6-14. Effect of crushing on the FTI elongation ratio results of coarse aggregates. 1E-7 1E-6 1E-5 1E-4 1E-3 0 20 40 60 80 100 Glacial Gravel Crushed 3/4'' Glacial Gravel Crushed 1/2'' Glacial Gravel Crushed 3/8'' Glacial Gravel Crushed #4 Glacial Gravel Rounded 3/4'' Glacial Gravel Rounded 1/2'' Glacial Gravel Rounded 3/8'' Glacial Gravel Rounded #4 Cu m ul at iv e pe rc en ta ge (% ) FTI Angularity Figure 6-15. Effect of crushing on the FTI angularity results of coarse aggregates. 1E-8 1E-7 1E-6 1E-5 1E-4 0 20 40 60 80 100 Cu m ul at iv e pe re ce nt ag e (% ) FTI Texture Glacial Gravel Crushed 3/4'' Glacial Gravel Crushed 1/2'' Glacial Gravel Crushed 3/8'' Glacial Gravel Crushed #4 Glacial Gravel Rounded 3/4'' Glacial Gravel Rounded 1/2'' Glacial Gravel Rounded 3/8'' Glacial Gravel Rounded #4 Figure 6-16. Effect of crushing on the FTI texture results of coarse aggregates. 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) Sphericity Glacial Gravel Crushed #8 Glacial Gravel Rounded #8 Glacial Gravel Crushed #16 Glacial Gravel Rounded #16 Figure 6-17. The FTI sphericity results of fine aggregates. 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) Flatness ratio Glacial Gravel Crushed #8 Glacial Gravel Rounded #8 Glacial Gravel Crushed #16 Glacial Gravel Rounded #16 Figure 6-18. The FTI flatness ratio results of fine aggregates. 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) Elongation ratio Glacial Gravel Crushed #8 Glacial Gravel Rounded #8 Glacial Gravel Crushed #16 Glacial Gravel Rounded #16 Figure 6-19. The FTI elongation ratio results of fine aggregates.

66 Test Method Aggregate Imaging System Estimated Equipment Cost ($) Analysis Speed Accuracy Ease of Use Repeatability Dynamic Digital Image Method VDG-40 videograder 45,000 H M M L Computerized particle analyzer 25,000 H M M M Micrometrics Optisizer particle size distribution analyzer (PSDA) 50,000 L M H L Video image system (VIS) 60,000 H M M L Camsizer 45,000 M M M L Winshape 35,000 H M M M UIAIA 35,000 M H M H Statistic Digital Image Method AIMS II 35,000 H H H H FTI 20,000 M H M H Note: H = high; M = medium; L = low. (Based on Masad et al., 2007). Table 6-8(a). Features of aggregate imaging systems. 1E-3 0.01 0.1 0 20 40 60 80 100 Cu m ul at iv e pe rc en ta ge (% ) FTI Angularity Glacial Gravel Crushed #8 Glacial Gravel Rounded #8 Glacial Gravel Crushed #16 Glacial Gravel Rounded #16 Figure 6-20. The FTI angularity results of fine aggregates. Both GGR and GGC fine aggregates are from Kent, MI, as shown in Table 4-4. The data presented in Table 6-7 indi- cate that the sphericities of GGR and GGC fine aggregates do not have a significant difference. The flatness ratio and elongation ratio of all the GGC fine aggregates are generally smaller than those of the GGR fine aggregates, except for the #4 and #16 aggregates. The greater values of the flatness ratio and the elongation ratio for GGC aggregates indicate that crushed aggregates (i.e., GGC) generally tend to be less flat and less elongated than natural aggregates (i.e., GGR). Also, an increase in the angularity and texture values from GGR to GGC aggregates is observed across all sizes. The increase of angularity and texture values from GGR to GGC suggests that both coarse and fine GGC aggregates are more angular with rougher surface texture than GGR aggregates. A possible reason that crushed aggregates have greater values of angu- larity and texture for fine aggregates is that fine aggregates may have more fractured surfaces. 6.6 Feature Comparisons of the FTI System to the Other Aggregate Imaging Systems Information collected from the literature review (in Appen- dix A) is presented in Table 6-8 to compare the features of nine available aggregate imaging techniques. There are two types of aggregate imaging technique (i.e., the dynamic digi- tal image method and the statistic digital image method). Apparently, the FTI system is much less expensive than the other aggregate imaging systems.

67 Aggregate Imaging System Aggregate Size Range No. of Cameras Dimension(s) of Image Measured Aggregate Characteristics Dynamic Digital Image Method VDG-40 videograder #16–1.5” 1 2 Shape Computerized particle analyzer #140–1.5” 1 2 Shape Micrometrics Optisizer PSDA #200–1.5” 1 2 Shape VIS #16–1.5” 1 2 Shape Camsizer #50–3/4” 2 2 Shape angularity Wi nshape #4–1” 2 3 Shape angularity UIAIA #8–1” 3 2 Shape angularity texture Statistic Digital Image Method AIMS II #200–1” 1 3 Shape angularity texture FTI #50–3/4” 1 3 Shape angularity texture Table 6-8(b). Features of aggregate imaging systems.