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22 TABLE 13 t/NMAS, temperature in C at 20 min., gyrations were increased up to 300 gyrations. This shows the asphalt high temperature grade, and difference in difficulty of compacting mixes at thinner lifts in the gyratory temperature mold. Permeability testing was only performed on specimens Section/Mix Temp. at Asphalt Difference that met the desired air voids. The results were very limited, 20 min., C Grade, PG but, did show that generally the coarser mixes (larger maxi- 1 2.5 60 67 -7 mum aggregate size or higher percentage of coarse aggregate) 9.5mmFG 3.6 82 67 15 5.1 95 67 28 had higher permeabilities. 2 2.1 64 67 -3 9.5mmCG 2.4 72 67 5 5.1 105 67 38 3 2.2 65 76 -11 4.7 EVALUATION OF EFFECT OF t/NMAS 9.5mmSMA 3.7 100 76 24 ON PERMEABILITY USING 5.2 112 76 36 VIBRATORY COMPACTOR 4 2.2 72 76 -4 12.5mmSMA 3.1 118 76 42 All specimens compacted at t/NMAS of 2.0, 3.0, and 4.0 did 3.8 120 76 44 achieve the target air void content, which was 7 1.0 percent. 5 2.6 124 67 57 19mmFG 3.0 122 67 55 Figure 34 shows the relationship between average permeabil- 5.2 130 67 63 ity for the two aggregate types and t/NMAS. In general, the 6 2.1 82 67 15 permeability decreased as t/NMAS increased. Most of the 19mmCG 3.2 120 67 53 mixes had permeability values fewer than 50 10-5 cm/sec. 5.1 118 67 51 7 2.7 86 76 10 However, at t/NMAS equal to 2.0, the 9.5-mm and 12.5-mm 19mmCG 3.8 120 76 44 NMAS SMA mixes had average permeability values of 173 5.2 142 76 66 10-5 cm/sec and 196 10-5 cm/sec, respectively. These values for the SMA exceed the recommended maximum permeability value of 125 10-5 cm/sec. It appears from these 4.6 EVALUATION OF EFFECT OF t/NMAS data that a specification requirement of 7 percent air voids ON PERMEABILITY USING GYRATORY COMPACTOR would be acceptable for all of the mixes if the t/NMAS is 3 or greater. The likely reason that the thinner samples have Specimens were compacted to 7.0 1.0 percent air void high permeability is that the voids are more likely to be inter- content at t/NMAS of 2.0, 3.0, and 4.0. For most mixes, spec- connected all the way through the samples when the samples imens could not achieve the target air voids even when the are thinner. Hence when mixes are placed thin, in this case 97.5 40 97.0 Steel Wheel Roller 30 96.5 Difference in Temperature Difference in Temperature, oC 96.0 20 %Lab Density 95.5 10 95.0 %Lab Density Difference in Temperature 94.5 Steel Roller 2 R = 0.9821 0 2 R = 0.6392 94.0 -10 93.5 93.0 -20 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 t/NMAS Figure 25. Relationships between density, t/NMAS, and temperature for Section 1.

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23 96.0 50.0 Difference in Temperature. 2 95.0 R = 0.998 40.0 94.0 30.0 Difference inTemperature, C o 93.0 %Lab Density 20.0 92.0 10.0 91.0 %Lab Density 0.0 %Lab Density Steel Roller 90.0 Steel/Rubber Tire Roller 2 R = 0.6796 2 R = 0.5115 -10.0 89.0 88.0 -20.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 t/NMAS Figure 26. Relationships between density, t/NMAS, and temperature for Section 2. 100.0 50 Difference in Temperature Steel Wheel Roller 2 99.0 R = 0.976 Rubber Tire Roller 40 %Lab Density Difference in Temperature Steel Roller 98.0 2 R = 0.8335 30 97.0 Difference in Temperature, C o 20 96.0 %Lab Density 95.0 10 94.0 %Lab Density 0 Steel/Rubber Tire Roller 93.0 2 R = 0.1864 -10 92.0 -20 91.0 90.0 -30 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 t/NMAS Figure 27. Relationships between density, t/NMAS, and temperature for Section 3.

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24 104.0 100 %Lab Density 103.0 Steel Roller 102.0 Steel Wheel Roller 2 R = 0.8711 Rubber Tire Roller 80 101.0 Difference in Temperatur e 100.0 99.0 98.0 60 Difference in Temperature, C o 97.0 96.0 %Lab Density 40 95.0 94.0 %Lab Density 93.0 Steel/Rubber Tire Roller 2 20 92.0 R = 0.7651 91.0 90.0 0 89.0 Difference in Temperature 2 R = 0.8884 88.0 87.0 -20 86.0 85.0 84.0 -40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 t/NMAS Figure 28. Relationships between density, t/NMAS, and temperature for Section 4. 105.0 70 Different in Temperature @ 20 Min. 2 R = 0.8191 104.0 60 103.0 50 102.0 Difference in Temperature, C o 101.0 %Lab Density 40 100.0 30 99.0 %Lab Density 98.0 Steel Roller 20 2 R = 0.7736 97.0 10 96.0 95.0 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 t/NMAS Figure 29. Relationships between density, t/NMAS, and temperature for Section 5.

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25 100 70 Difference in Temperature 2 R = 0.6816 99 60 Steel/Rubber Tire Roller 98 Difference in Temperature 50 Difference in Temperature, C %Lab Density 97 40 96 30 95 20 Steel/Rubber Tire Roller 2 94 R = 0.4489 10 93 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 t/NMAS Figure 30. Relationships between density, t/NMAS, and temperature for Section 6. 100.0 70 Steel Roller 99.0 60 Steel/Rubber Tire Roller 98.0 Difference in Temperature 50 97.0 40 96.0 %Lab Density Difference in Temperature,C Steel Roller 2 30 95.0 R = 0.6529 %Lab Density 94.0 20 93.0 10 92.0 Difference in Temperature %Lab Density 0 2 R = 0.9904 Steel/Rubber Tire Roller 91.0 2 R = 0.8092 -10 90.0 -20 89.0 88.0 -30 87.0 -40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 t/NMAS Figure 31. Relationships between density, t/NMAS, and temperature for Section 7.

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26 104.0 102.0 100.0 98.0 2 y = -0.8216x + 7.2531x + 80.848 2 R = 0.2562 %Lab Density 96.0 94.0 92.0 90.0 88.0 86.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 t/NMAS Figure 32. Relationships between density and t/NMAS for all sections. 180 25 mm (1.0") 32 mm (1.25") 160 38 mm (1.5") 44 mm (1.75") 140 51 mm (2.0") 64 mm (2.5") 89 mm (3.5") Temperature of Mix, C 120 100 80 60 40 20 0 0 10 20 30 40 50 60 70 Time, min. Figure 33. The effect of layer t/NMAS and cooling time on mix temperature.