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From page 26... ... 26 Introduction As stated in ASTM E1169: Standard Practice for Conducting Ruggedness Tests, a ruggedness test consists of six steps: (1) select testing factors and their levels, (2) Read the entire page →
From page 27... ... Findings and Applications 27 PB Design Order Actual Run Order Specimen Thickness, mm Notch Depth, mm Loading Hole Location, mm Air Voids, % Crack Opening Rate, mm/min Test Temperature, oC Specimen Conditioning Time, h 1 6 55 65 28 6.0 1.05 PG low+9 2 2 15 45 65 28 8.0 0.95 PG low+11 2 3 13 45 59 28 8.0 1.05 PG low+9 8 4 16 55 59 22 8.0 1.05 PG low+11 2 5 8 45 65 22 6.0 1.05 PG low+11 8 6 3 55 59 28 6.0 0.95 PG low+11 8 7 4 55 65 22 8.0 0.95 PG low+9 8 8 12 45 59 22 6.0 0.95 PG low+9 2 9 7 55 65 28 6.0 1.05 PG low+9 2 10 11 45 65 28 8.0 0.95 PG low+11 2 11 2 45 59 28 8.0 1.05 PG low+9 8 12 14 55 59 22 8.0 1.05 PG low+11 2 13 10 45 65 22 6.0 1.05 PG low+11 8 14 1 55 59 28 6.0 0.95 PG low+11 8 15 5 55 65 22 8.0 0.95 PG low+9 8 16 9 45 59 22 6.0 0.95 PG low+9 2 PB Order A: Specimen Thickness B: Notch Depth C: Loading Hole Location D: Air Voids E: Crack Opening Rate F: Test Temperature G: Specimen Conditioning Time Rep 1 Gf Rep 2 Gf Rep Ave Gf Rep Gf Diff. 1 1 1 1 –1 1 –1 –1 841 880 861 39 2 –1 1 1 1 –1 1 –1 677 990 834 313 3 –1 –1 1 1 1 –1 1 729 473 601 –256 4 1 –1 –1 1 1 1 –1 787 991 889 204 5 –1 1 –1 –1 1 1 1 693 796 745 103 6 1 –1 1 –1 –1 1 1 1047 613 830 –434 7 1 1 –1 1 –1 –1 1 773 510 642 –263 8 –1 –1 –1 –1 –1 –1 –1 835 765 800 –70 Ave + 805.25 770.00 781.25 741.25 773.75 824.25 704.25 Sd 257.21 Ave − 744.75 780.00 768.75 808.75 776.25 725.75 845.75 Sr 181.88 Main Effect 60.50 –10.00 12.50 –67.50 –2.50 98.50 –141.50 Seffect 90.94 Table 14. Read the entire page →
From page 28... ... 28 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Thickness B: Notch Depth C: Loading Hole Location D: Air Voids E: Crack Opening Rate F: Test Temperature G: Specimen Conditioning Time Rep 1 Gf Rep 2 Gf Rep Ave Gf Rep Gf Diff. 1 1 1 1 –1 1 –1 –1 552 420 486 –132 2 –1 1 1 1 –1 1 –1 332 297 315 –35 3 –1 –1 1 1 1 –1 1 301 319 310 18 4 1 –1 –1 1 1 1 –1 507 529 518 22 5 –1 1 –1 –1 1 1 1 322 482 402 160 6 1 –1 1 –1 –1 1 1 332 457 395 125 7 1 1 –1 1 –1 –1 1 374 443 409 69 8 –1 –1 –1 –1 –1 –1 –1 303 383 343 80 Ave + 451.75 402.75 376.25 387.75 429.00 407.25 378.75 Sd 92.63 Ave − 342.38 391.38 417.88 406.38 365.13 386.88 415.38 Sr 65.50 Main Effect 109.38 11.38 –41.63 –18.63 63.88 20.38 –36.63 Seffect 32.75 PB Order A: Specimen Thickness B: Notch Depth C: Loading Hole Location D: Air Voids E: Crack Opening Rate F: Test Temperature G: Specimen Conditioning Time Rep 1 Gf Rep 2 Gf Rep Ave Gf Rep Gf Diff. Read the entire page →
From page 29... ... Findings and Applications 29 Similarly, all effects of the other six factors for each mix are presented in Table 15, Table 16, and Table 17 for 12.5-mm SMA, 12.5-mm Superpave, and 9.5-mm Superpave, respectively. • Standard deviation of the difference, Sd: The standard error of effects from the dispersion of differences between replicates can be estimated from the standard deviation of the differences. Read the entire page →
From page 30... ... 30 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Effect Order Factor \|Effect\| Student's t-value p-value Half-Normal 7 A (specimen thickness) 109.38 3.34 0.012 1.803 1 B (notch depth) Read the entire page →
From page 31... ... Findings and Applications 31 A (Specimen thickness) B (Notch depth) Read the entire page →
From page 32... ... 32 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Table 21 shows the estimated tolerance of Factor A (specimen thickness) for the 12.5-mm Superpave mixture. Read the entire page →
From page 33... ... Findings and Applications 33 in this study was ±3 mm, and Factor B was not found to be significant for all three mixtures. Since there was not an appreciable difference between ±2.5 mm and ±3.0 mm, and increasing the tolerance to ±3.0 mm did not affect the results, the tolerance of the notch depth, being conservative, should be kept as it is in the current method: ±2.5 mm. Read the entire page →
From page 34... ... 34 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance happen when a DCT specimen is moved out of a conditioning chamber to the DCT test machine and the specimen is inserted into the loading fixture. This process may take 2 to 5 min. Read the entire page →
From page 35... ... Findings and Applications 35 PB Design Order Actual Run Order Specimen Thickness, mm Notch Depth, mm Notch Location, mm Specimen Height, mm Air Voids, % Crack Opening Rate, mm/min Test Temperature, °C 1 15 27 17 77 71.5 8.0 0.029 PG low+9 2 2 23 17 77 75.5 6.0 0.032 PG low+9 3 16 23 13 77 75.5 8.0 0.029 PG low+11 4 6 27 13 75 75.5 8.0 0.032 PG low+9 5 13 23 17 75 71.5 8.0 0.032 PG low+11 6 12 27 13 77 71.5 6.0 0.032 PG low+11 7 8 27 17 75 75.5 6.0 0.029 PG low+11 8 1 23 13 75 71.5 6.0 0.029 PG low+9 9 10 27 17 77 71.5 8.0 0.029 PG low+9 10 7 23 17 77 75.5 6.0 0.032 PG low+9 11 5 23 13 77 75.5 8.0 0.029 PG low+11 12 11 27 13 75 75.5 8.0 0.032 PG low+9 13 4 23 17 75 71.5 8.0 0.032 PG low+11 14 3 27 13 77 71.5 6.0 0.032 PG low+11 15 14 27 17 75 75.5 6.0 0.029 PG low+11 16 9 23 13 75 71.5 6.0 0.029 PG low+9 PB Order A: Specimen Thickness B: Notch Depth C: Notch Location D: Specimen Height E: Air Voids F: Crack Opening Rate G: Test Temperature Rep 1 Gf Rep 2 Gf Rep Ave Gf Rep Gf Diff. 1 1 1 1 –1 1 –1 –1 498 539 518 41 2 –1 1 1 1 –1 1 –1 585 798 691 213 3 –1 –1 1 1 1 –1 1 783 454 618 –329 4 1 –1 –1 1 1 1 –1 735 577 656 –158 5 –1 1 –1 –1 1 1 1 425 400 413 –25 6 1 –1 1 –1 –1 1 1 509 796 652 288 7 1 1 –1 1 –1 –1 1 699 449 574 –251 8 –1 –1 –1 –1 –1 –1 –1 494 464 479 –29 Ave + 600.23 549.06 620.12 635.00 551.37 603.15 564.37 Sd 213.65 Ave − 550.30 601.48 530.41 515.54 599.16 547.38 586.16 Sr 151.08 Main Effect 49.93 –52.42 89.71 119.46 –47.80 55.76 –21.79 Seffect 75.54 Table 23. Read the entire page →
From page 36... ... 36 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Thickness B: Notch Depth C: Notch Location D: Specimen Height E: Air Voids F: Crack Opening Rate G: Test Temperature Rep 1 Gf Rep 2 Gf Rep Ave Gf Rep Gf Diff. 1 1 1 1 –1 1 –1 –1 194 282 238 88 2 –1 1 1 1 –1 1 –1 232 314 273 82 3 –1 –1 1 1 1 –1 1 372 497 434 125 4 1 –1 –1 1 1 1 –1 322 261 292 –61 5 –1 1 –1 –1 1 1 1 331 204 267 –127 6 1 –1 1 –1 –1 1 1 358 330 344 –28 7 1 1 –1 1 –1 –1 1 458 312 385 –145 8 –1 –1 –1 –1 –1 –1 –1 323 198 261 –125 Ave + 314.62 290.77 322.33 345.95 307.79 293.90 357.65 Sd 108.85 Ave − 308.76 332.61 301.05 277.43 315.60 329.48 265.73 Sr 76.97 Main Effect 5.86 –41.84 21.28 68.52 –7.81 –35.58 91.92 Seffect 38.49 PB Order A: Specimen Thickness B: Notch Depth C: Location of Loading Hole D: Air Voids E: Crack Opening Rate F: Test Temperature G: Specimen Conditioning Time Rep 1 Gf Rep 2 Gf Rep Ave Gf Rep Gf Diff. Read the entire page →
From page 37... ... Findings and Applications 37 • Standard deviation of the difference, Sd: The standard error of effects from the dispersion of differences between replicates was estimated through the standard deviation of the differences. The standard deviations of the differences were calculated and are listed in Table 24, Table 25, and Table 26 for 12.5-mm SMA, 12.5-mm Superpave, and 9.5-mm Superpave, respectively. Read the entire page →
From page 38... ... 38 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance – Half-normal plot: The half-normal plots for the 12.5-mm SMA, 12.5-mm Superpave, and 9.5-mm Superpave are shown in Figure 23, Figure 24, and Figure 25, respectively. No factor is shown to be significant in either Figure 23 (12.5-mm SMA) Read the entire page →
From page 39... ... Findings and Applications 39 A (Specimen thickness) B (Notch depth) Read the entire page →
From page 40... ... 40 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance tolerance of ±2.0 mm for the specimen thickness is said to be rugged, and no change is needed. Any further increase in the tolerance for the specimen thickness may cause problems when setting the specimen into the SCB fixture because the gap between the two U-shaped frames is fixed (see Figure 2 in Appendix B) Read the entire page →
From page 41... ... Findings and Applications 41 • Air Voids: Air voids of SCB specimens are not specified in the current AASHTO TP 105-13. The tolerance of the air voids (Factor E) Read the entire page →
From page 42... ... 42 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance In summary, the research team proposes changes to the current version of AASHTO TP 105-13; a proposed revision to AASHTO TP 105-13, including all information discussed herein, is documented in Appendix B Ruggedness Evaluation of AASHTO TP 124-18: SCB-FI -- Findings and Application Execution of the Experimental Design for AASHTO TP 124-18 Ruggedness Test The SCB-FI test was executed according to AASHTO TP 124-18 guidelines in random run order (Table 31) Read the entire page →
From page 43... ... Findings and Applications 43 Statistical Analysis of Ruggedness Testing of AASHTO TP 124-18: SCB-FI Based on the procedures described in ASTM E1169, the statistical analysis of ruggedness test was performed using the following steps for each mixture tested in this study. • Factor effects: The effects of the seven factors for each mixture were calculated and are presented in Table 32, Table 33, and Table 34 for the 12.5-mm SMA, 12.5-mm Superpave, and 9.5-mm Superpave mixtures, respectively. Read the entire page →
From page 44... ... 44 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Thickness B: Notch Depth C: Notch Location D: Specimen Height E: Air Voids F: Loading Rate G: Test Temp. Read the entire page →
From page 45... ... Findings and Applications 45 – Half-normal plot: The half-normal plots for the 12.5-mm SMA, 12.5-mm Superpave, and 9.5-mm Superpave mixtures are shown in Figure 27, Figure 28, and Figure 29, respectively. In Figure 27 (12.5-mm SMA) Read the entire page →
From page 46... ... 46 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance A (Specimen thickness) B (Notch depth) Read the entire page →
From page 47... ... Findings and Applications 47 Estimation of Tolerance for Significant Factors As identified previously, the two significant factors for the SCB-FI test were air voids and test temperature. Table 38 shows the estimated tolerances of Factors E (air voids) Read the entire page →
From page 48... ... 48 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance • Specimen Height: Similar to the notch location, AASHTO TP 124-18 has no specific requirement on specimen height. It says, "Cut each cylindrical specimen exactly in half to produce two identical, semicircular specimens." It is extremely difficult to get two identical semicircular specimens. Read the entire page →
From page 49... ... Findings and Applications 49 • Statistical analysis to identify statistically significant effects: The statistical significance of the factor effects and half-normal values for the half-normal plot are shown in Table 42. – Student's t test: Dividing the effect by Seffect provides a Student's t-value, which had 7 degrees of freedom for this study. Read the entire page →
From page 50... ... 50 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Revision of ASTM D8044-16: SCB-Jc Test Method Table 43 lists the seven factors used in this study and associated tolerances for each factor specified in ASTM D8044-16. Since no factor was significant, revision of the ASTM D8044-16 test method is warranted because it may be beneficial to relax some specific requirements of these factors. Read the entire page →
From page 51... ... Findings and Applications 51 a negative influence on the Jc results. Thus, the research team recommends a tolerance of ±2.0 mm for specimen thickness, which will make specimen preparation more efficient without affecting the test results. Read the entire page →
From page 52... ... 52 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance voids of SCB specimens were nonsignificant, the research team suggests increasing the tolerance for air voids to ±1%. The proposed change will make specimen preparation more efficient without affecting the test results. Read the entire page →
From page 53... ... Findings and Applications 53 PB Design Order Actual Run Order Specimen Thickness, mm Specimen Center Location Air Voids, % Loading Rate, mm/min Contact Load Test Temperature, °C Conditioning Method 1 9 64 2 mm off 8.0 48 Yes (0.1 kN) 24 Water 2 6 60 2 mm off 8.0 52 No (0 kN) Read the entire page →
From page 54... ... 54 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Thickness B: Specimen Center Location C: Air Voids D: Loading Rate E: Contact Load F: Test Temp. G: Condit. Read the entire page →
From page 55... ... Findings and Applications 55 Effect Order Factor \|Effect\| Student's tvalue p-value HalfNormal 7 C (air voids) 207.29 2.91 0.023 1.803 6 E (contact load) Read the entire page →
From page 56... ... 56 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Figure 31. Half-normal plot for the CTIndex test with the 12.5-mm SMA mixture. Read the entire page →
From page 57... ... Findings and Applications 57 Figure 33. Half-normal plot for the CTIndex test with the 9.5-mm Superpave mixture. Read the entire page →
From page 58... ... 58 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance • Specimen Location: Currently, ASTM D8225-19 requires "ensuring specimen is centered." Since specimen location was not a significant factor, the research team proposes a tolerance of ±2 mm off the center of the loading fixture, which will allow users to run the test more efficiently without affecting the test results. • Air Voids: The only significant factor for IDEAL-CT was air voids. Read the entire page →
From page 59... ... Findings and Applications 59 PB Design Order Actual Run Order Specimen Height, mm Specimen Width, mm Air Voids, % Crack Opening Displacement, mm Loading Period, s Block Weight, lb Test Temperature, °C 1 8 40 78 8.0 0.61 11 5 24 2 1 36 78 8.0 0.66 9 10 24 3 5 36 74 8.0 0.66 11 5 26 4 10 40 74 6.0 0.66 11 10 24 5 13 36 78 6.0 0.61 11 10 26 6 16 40 74 8.0 0.61 9 10 26 7 14 40 78 6.0 0.66 9 5 26 8 4 36 74 6.0 0.61 9 5 24 9 11 40 78 8.0 0.61 11 5 24 10 6 36 78 8.0 0.66 9 10 24 11 7 36 74 8.0 0.66 11 5 26 12 12 40 74 6.0 0.66 11 10 24 13 9 36 78 6.0 0.61 11 10 26 14 15 40 74 8.0 0.61 9 10 26 15 3 40 78 6.0 0.66 9 5 26 16 2 36 74 6.0 0.61 9 5 24 PB Order A: Specimen Height B: Specimen Width C: Air Voids D: Crack Opening Displ. E: Loading Period F: Block Weight G: Test Temp. Read the entire page →
From page 60... ... 60 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Height B: Specimen Width C: Air Voids D: Crack Opening Displ. E: Loading Period F: Block Weight G: Test Temp. Read the entire page →
From page 61... ... Findings and Applications 61 PB Order A: Specimen Height B: Specimen Width C: Air Voids D: Crack Opening Displ. E: Loading Period F: Block Weight G: Test Temp. Read the entire page →
From page 62... ... 62 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Height B: Specimen Width C: Air Voids D: Crack Opening Displ. E: Loading Period F: Block Weight G: Test Temp. Read the entire page →
From page 63... ... Findings and Applications 63 PB Order A: Specimen Height B: Specimen Width C: Air Voids D: Crack Opening Displ. E: Loading Period F: Block Weight G: Test Temp. Read the entire page →
From page 64... ... 64 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Statistical Analysis of Ruggedness Testing of Tex-248-F: OT Based on the procedures described in ASTM E1169, the statistical analysis of ruggedness testing was performed using the following steps for each mixture tested in this study. • Factor effects: The effects of the seven factors for all three cracking parameters of each mixture were calculated. Read the entire page →
From page 65... ... Findings and Applications 65 Effect Order Factor \|Effect\| Student's t-value p-value Half-Normal 6 A (specimen height) 0.31 2.61 0.035 1.242 5 B (specimen width) Read the entire page →
From page 66... ... 66 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Effect Order Factor \|Effect\| Student's t-value p-value Half-Normal 7 A (specimen height) 27.99 3.59 0.009 1.803 1 B (specimen width) Read the entire page →
From page 67... ... Findings and Applications 67 Effect Order Factor \|Effect\| Student's t-value p-value Half-Normal 7 A (specimen height) 74.75 4.72 0.002 1.803 3 B (specimen width) Read the entire page →
From page 68... ... 68 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Figure 34. Half-normal plot for the CFE of the 12.5-mm SMA mixture. Read the entire page →
From page 69... ... Findings and Applications 69 Figure 36. Half-normal plot for the CFE of the 12.5-mm Superpave mixture. Read the entire page →
From page 70... ... 70 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Figure 38. Half-normal plot for the number of cycles to failure of the 12.5-mm Superpave mixture. Read the entire page →
From page 71... ... Findings and Applications 71 Figure 40. Half-normal plot for the CRI of the 9.5-mm Superpave mixture. Read the entire page →
From page 72... ... 72 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Estimation of Tolerance for Significant Factors As mentioned earlier, four factors were significant for the OT. Tolerances for these four factors were estimated using Equation 3. Read the entire page →
From page 73... ... Findings and Applications 73 to ±1 mm, it is recommended that the current tolerance of ±0.5 mm for specimen height in Tex-248-F (May 2017) be kept for two reasons: (1) Read the entire page →
From page 74... ... 74 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance • Test duration for the 12.5-mm SMA mixture: The original plan was to use the same factor levels for all three mixtures, as listed in Table 9. However, the research team discovered that it took 6 weeks to complete the testing for one SMA beam at the original high strain level (788 microstrain) Read the entire page →
From page 75... ... Findings and Applications 75 PB Design Order Actual Run Order Specimen Height, mm Specimen Width, mm Specimen Length, mm Air Voids, % Loading Frequency, Hz Strain Level, Microstrain Test Temperature, °C 1 12 56 69 386 6.0 10 1,045 19 2 6 44 69 386 8.0 5 1,155 19 3 15 44 57 386 8.0 10 1,045 21 4 16 56 57 374 8.0 10 1,155 19 5 10 44 69 374 6.0 10 1,155 21 6 14 56 57 386 6.0 5 1,155 21 7 4 56 69 374 8.0 5 1,045 21 8 13 44 57 374 6.0 5 1,045 19 9 5 56 69 386 6.0 10 1,045 19 10 11 44 69 386 8.0 5 1,155 19 11 3 44 57 386 8.0 10 1,045 21 12 9 56 57 374 8.0 10 1,155 19 13 1 44 69 374 6.0 10 1,155 21 14 8 56 57 386 6.0 5 1,155 21 15 7 56 69 374 8.0 5 1,045 21 16 2 44 57 374 6.0 5 1,045 19 PB Design Order Actual Run Order Specimen Height, mm Specimen Width, mm Specimen Length, mm Air Voids, % Loading Frequency, Hz Strain Level, Microstrain Test Temperature, °C 1 12 56 69 386 6.0 10 713 19 2 6 44 69 386 8.0 5 788 19 3 15 44 57 386 8.0 10 713 21 4 16 56 57 374 8.0 10 788 19 5 10 44 69 374 6.0 10 788 21 6 14 56 57 386 6.0 5 788 21 7 4 56 69 374 8.0 5 713 21 8 13 44 57 374 6.0 5 713 19 9 5 56 69 386 6.0 10 713 19 10 11 44 69 386 8.0 5 788 19 11 3 44 57 386 8.0 10 713 21 12 9 56 57 374 8.0 10 788 19 13 1 44 69 374 6.0 10 788 21 14 8 56 57 386 6.0 5 788 21 15 7 56 69 374 8.0 5 713 21 16 2 44 57 374 6.0 5 713 19 Table 76. Replicated eight runs in random order for AASHTO T 321-17 with the 12.5-mm SMA mixture. Read the entire page →
From page 76... ... 76 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Height B: Specimen Width C: Specimen Length D: Air Voids E: Loading Frequency F: Strain Level G: Test Temperature Rep 1 Nf Rep 2 Nf Rep Ave Nf Rep Nf Diff. 1 1 1 1 –1 1 –1 –1 373,000 201,500 287,250 –171,500 2 –1 1 1 1 –1 1 –1 254,996 393,000 323,998 138,004 3 –1 –1 1 1 1 –1 1 919,996 318,496 619,246 –601,500 4 1 –1 –1 1 1 1 –1 381,996 355,996 368,996 –26,000 5 –1 1 –1 –1 1 1 1 145,496 216,496 180,996 71,000 6 1 –1 1 –1 –1 1 1 1,155,000 579,996 867,498 –575,004 7 1 1 –1 1 –1 –1 1 854,996 130,9996 1,082,496 455,000 8 –1 –1 –1 –1 –1 –1 –1 627,996 1,534,996 1,081,496 907,000 Ave + 651,560.0 468,685.0 524,498.0 598,684.0 364,122.0 435,372.0 687,559.0 Sd 503,052.0 Ave − 551,434.0 734,309.0 678,496.0 604,310.0 838,872.0 767,622.0 515,435.0 Sr 355,711.5 Main Effect 100,126.0 –265,624.0 –153,998.0 –5,626.0 –474,750.0 –332,250.0 172,124.0 Seffect 177,855.7 PB Order A: Specimen Height B: Specimen Width C: Specimen Length D: Air Voids E: Loading Frequency F: Strain Level G: Test Temperature Rep 1 Nf Rep 2 Nf Rep Ave Nf Rep Nf Diff. Read the entire page →
From page 77... ... Findings and Applications 77 PB Order A: Specimen Height B: Specimen Width C: Specimen Length D: Air Voids E: Loading Frequency F: Strain Level G: Test Temperature Rep 1 Nf Rep 2 Nf Rep Ave Nf Rep Nf Diff. 1 1 1 1 –1 1 –1 –1 23,096 33,050 28,073 9,954 2 –1 1 1 1 –1 1 –1 16,446 64,100 40,273 47,654 3 –1 –1 1 1 1 –1 1 15,496 20,500 17,998 5,004 4 1 –1 –1 1 1 1 –1 19,846 11,500 15,673 –8,346 5 –1 1 –1 –1 1 1 1 15,900 10,946 13,423 –4,954 6 1 –1 1 –1 –1 1 1 38,396 32,998 35,697 –5,398 7 1 1 –1 1 –1 –1 1 54,100 56,996 55,548 2,896 8 –1 –1 –1 –1 –1 –1 –1 37,746 25,350 31,548 –12,396 Ave + 33,747.8 34,329.3 30,510.3 32,373.0 18,791.8 26,266.5 30,666.5 Sd 19,020.2 Ave − 25,810.5 25,229.0 29,048.0 27,185.3 40,766.5 33,291.8 28,891.8 Sr 13,449.3 Main Effect 7,937.3 9,100.3 1,462.3 5,187.8 –21,974.8 –7,025.3 1,774.8 Seffect 6,724.7 Effect Order Factor \|Effect\| Student's tvalue pvalue HalfNormal 2 A (specimen height) Read the entire page →
From page 78... ... 78 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Effect Order Factor \|Effect\| Student's t-value p-value Half-Normal 5 A (specimen height) 7,937.25 1.1803 0.276 0.921 6 B (specimen width) Read the entire page →
From page 79... ... Findings and Applications 79 Figure 43. Half-normal plot: AASHTO T 321-17: BBF ruggedness test with the 12.5-mm Superpave mixture. Read the entire page →
From page 80... ... 80 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Figure 44. Half-normal plot: AASHTO T 321-17: BBF ruggedness test with the 9.5-mm Superpave mixture. Read the entire page →
From page 81... ... Findings and Applications 81 revision of AASHTO T 321-17 is warranted. In addition, it may be beneficial to relax some requirements for the nonsignificant factors. Read the entire page →
From page 82... ... 82 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Note 7 -- Ruggedness testing indicated that the loading frequency had significant impact on fatigue life of asphalt mixtures; the loading frequency should be controlled within the target loading frequency ±2 Hz to have a statistically equal fatigue life. Furthermore, asphalt mixtures had statistically equal fatigue lives when the strain level was limited within ±5% of the target strain level. Read the entire page →
From page 83... ... Findings and Applications 83 PB Design Order Actual Run Order Specimen Thickness, mm Air Voids, % Rest Period between and Creep Tests, min MR Temperature Equilibrium Time, min Rest Period between Creep and Fracture Tests, min Loading Rate, mm/min Test Temperature, °C 1 1 40 8.0 15 30 15 48 9 2 8 36 8.0 15 60 5 52 9 3 15 36 6.0 15 60 15 48 11 4 6 40 6.0 5 60 15 52 9 5 9 36 8.0 5 30 15 52 11 6 5 40 6.0 15 30 5 52 11 7 11 40 8.0 5 60 5 48 11 8 14 36 6.0 5 30 5 48 9 9 3 40 8.0 15 30 15 48 9 10 16 36 8.0 15 60 5 52 9 11 13 36 6.0 15 60 15 48 11 12 7 40 6.0 5 60 15 52 9 13 12 36 8.0 5 30 15 52 11 14 2 40 6.0 15 30 5 52 11 15 10 40 8.0 5 60 5 48 11 16 4 36 6.0 5 30 5 48 9 PB Order A: Specimen Thickness B: Air Voids C: Rest Period between MR and Creep Tests D: Temperature Equilibrium Time E: Rest Period between Creep and Fracture Tests F: Loading Rate G: Test Temperature Rep 1 ER Rep 2 ER Rep Ave ER Rep ER Diff. 1 1 1 1 –1 1 –1 –1 1.541 3.333 2.437 1.793 2 –1 1 1 1 –1 1 –1 1.200 1.511 1.356 0.311 3 –1 –1 1 1 1 –1 1 3.097 1.487 2.292 –1.610 4 1 –1 –1 1 1 1 –1 2.495 3.179 2.837 0.684 5 –1 1 –1 –1 1 1 1 1.192 0.915 1.054 –0.277 6 1 –1 1 –1 –1 1 1 1.836 2.630 2.233 0.794 7 1 1 –1 1 –1 –1 1 2.757 2.820 2.788 0.063 8 –1 –1 –1 –1 –1 –1 –1 2.944 2.246 2.595 –0.699 Ave + 2.574 1.909 2.079 2.318 2.155 1.870 2.092 Sd 1.030 Ave − 1.824 2.489 2.319 2.080 2.243 2.528 2.306 Sr 0.729 Main Effect 0.750 –0.580 –0.239 0.239 –0.088 –0.658 –0.214 Seffect 0.364 Table 86. Read the entire page →
From page 84... ... 84 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance PB Order A: Specimen Thickness B: Air Voids C: Rest Period between MR and Creep Tests D: Temperature Equilibrium Time E: Rest Period between Creep and Fracture Tests F: Loading Rate G: Test Temperature Rep 1 ER Rep 2 ER Rep Ave ER Rep ER Diff. 1 1 1 1 –1 1 –1 –1 0.982 1.881 1.431 0.900 2 –1 1 1 1 –1 1 –1 0.962 1.233 1.098 0.272 3 –1 –1 1 1 1 –1 1 1.584 1.220 1.402 –0.364 4 1 –1 –1 1 1 1 –1 2.430 1.846 2.138 –0.584 5 –1 1 –1 –1 1 1 1 1.088 0.693 0.891 –0.395 6 1 –1 1 –1 –1 1 1 2.012 1.684 1.848 –0.329 7 1 1 –1 1 –1 –1 1 0.994 1.125 1.059 0.131 8 –1 –1 –1 –1 –1 –1 –1 1.482 1.571 1.526 0.090 Ave + 1.619 1.120 1.445 1.424 1.465 1.493 1.300 Sd 0.484 Ave − 1.229 1.729 1.403 1.424 1.383 1.355 1.548 Sr 0.342 Main Effect 0.390 –0.609 0.041 0.000 0.083 0.139 –0.248 Seffect 0.171 PB Order A: Specimen Thickness B: Air Voids C: Rest Period between MR and Creep Tests D: Temperature Equilibrium Time E: Rest Period between Creep and Fracture Tests F: Loading Rate G: Test Temperature Rep 1 ER Rep 2 ER Rep Ave ER Rep ER Diff. Read the entire page →
From page 85... ... Findings and Applications 85 Effect Order Factor \|Effect\| Student's t-value p-value Half-Normal 7 A (specimen thickness) 0.750 2.059 0.079 1.803 5 B (air voids) Read the entire page →
From page 86... ... 86 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance As seen from the three tables, there were two statistically significant factors: Factor B, air voids, and Factor G, test temperature. Not only was Factor B, air voids, the most significant factor with the smallest p-value, it was statistically significant for both the 12.5-mm Superpave mixture and the 9.5-mm Superpave mixture. Read the entire page →
From page 87... ... Findings and Applications 87 Figure 46. Half-normal plot: UF-IDT ruggedness test with the 12.5-mm Superpave mixture. Read the entire page →
From page 88... ... 88 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Estimation of Nonsignificant Intervals for Significant Factors Table 93 shows the tolerances of Factors B (air voids) and G (test temperature) Read the entire page →
From page 89... ... Findings and Applications 89 note was added to Subsection 4.2 of Appendix I: Proposed Revision to Standard Method of Test for Tensile Creep Compliance, Tensile Failure Limits, and Energy Ratio of Asphalt Mixtures Using the Superpave Indirect Tension (IDT) Test: Note 1 -- Ruggedness testing indicated that the asphalt mixtures had statistically equal energy ratios when the rest period between the MR test and the creep test ranged from 5 to 15 min. Read the entire page →
From page 90... ... 90 Ruggedness of Laboratory Tests for Asphalt Mixture Cracking Resistance Asphalt Mixtures Using the Superpave Indirect Tension (IDT) Test and Appendix I: Proposed Revision to Standard Method of Test for Tensile Creep Compliance, Tensile Failure Limits, and Energy Ratio of Asphalt Mixtures Using the Superpave Indirect Tension (IDT) Read the entire page →

From page 26...

... 26 Introduction As stated in ASTM E1169: Standard Practice for Conducting Ruggedness Tests, a ruggedness test consists of six steps: (1) select testing factors and their levels, (2)