Comparison of 9.5 mm SuperPave and Marshall Wearing I Mixes in ...

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45Table 5.1 Blend Percentages for Marshall Mix DesignsStockpile TypesTraffic Level Skid N. Sand L. Sand #9 BH FinesHeavy (100% L. Stone) 35 0 46 18 1Medium (100% L.Stone) 34 0 50 15 1Heavy (13% nat. sand) 20 13 28 38 1Medium (13% nat. sand) 20 13 28 38 1The mix designs from J. F. Allen indicated optimum asphalt contents were 5.2% and 5.5% for theheavy and medium traffic levels respectively. Calculations were performed to determine therequired aggregate and asphalt weights based on a mix sample weight of 1200 g. The requiredaggregate weight was input into the spreadsheet to get the weight required on each sieve.J.F. Allen's mix design indicated the 100% crushed limestone mixtures had VMA values of 15.0for the heavy traffic level and 15.1 for the medium traffic level, right at the minimum value of15. This raised a question of what the effect of natural sand would have on the VMA. It washypothesized that if the gradation of the mixes containing sand were similar to the 100%limestone mixtures, the VMA would decrease. This would put the mixture out of specification.A trial mix with 15% natural sand and a gradation similar to the 100% limestone mix wasprepared with an asphalt content of 5.5%. The resulting VMA was 13.1. This confirmed theneed to modify the gradation of the mixes with natural sand.Through a trial and error process, it was determined that the maximum amount of sand thatcould be used in the mix and have acceptable volumetric properties was 13 percent sand. Usingstockpile blend proportions that held the gradation curve farther away from the maximumdensity line counteracted the earlier problem of low VMA. In theory, keeping the gradationcurve farther away from the maximum density line would provide for more space between theaggregates in the mix, thus resulting in higher VMA values. Resulting stockpile proportions forboth Marshall heavy and medium mixtures containing natural sand can be found in Table 5.1.Coincidentally, the same gradation
Percent Passing4610090100% Limestone Heavy100% Limestone Medium13% N. Sand Hvy and Med80706050403020100#200 #50 #30 #16 #8 #4 3/8"Sieve1/2"Figure 5.1 Marshall gradation curves
Page 1 and 2:
COMPARISON OF 9.5 MM SUPERPAVE ANDM
Page 3 and 4: iNOTICEThe contents of this report
Page 5 and 6: iiiasphalt concrete wearing courses
Page 7 and 8: vMixing Procedure 78Appendix B Fine
Page 9 and 10: viiTable C-7 Marshall Medium 13% NS
Page 13 and 14: 4Table 1.1 Mix Design Types in Expe
Page 15 and 16: 6CHAPTER 2 LITERATURE REVIEW2.1 INT
Page 17 and 18: 82. determine aggregate stockpile b
Page 19 and 20: 10SieveAllowable PercentPassing Sie
Page 21 and 22: 12Stability is recorded as the maxi
Page 23 and 24: 14The WVDOH procedure for determini
Page 25 and 26: 16sieve. This is somewhat different
Page 27 and 28: 18G sb = bulk specific gravity of a
Page 29 and 30: 20theoretical gravity at the initia
Page 31 and 32: 22D/B est = adjusted dust to binder
Page 33 and 34: 24P b,est - 0.5%,P b,est ,P b,est +
Page 35 and 36: Percent Passing261009080Superpave U
Page 37 and 38: 28Table 2.6 WVDOH Marshall and Supe
Page 39 and 40: 30Table 2.9 Habib Marshall Analysis
Page 41 and 42: 32theoretically correct in that the
Page 43 and 44: 34the machine. This variability was
Page 45 and 46: 36CHAPTER 3 EQUIPMENT3.1 INTRODUCTI
Page 47 and 48: 38Hose PressureWheel Load100 psi100
Page 49 and 50: 40mouth. This jar rests on a holder
Page 51 and 52: problematic, as the saturated surfa
Page 53: 44Mechanical Laboratory Sieve. Afte
Page 57 and 58: 48Maximum specific gravity is a req
Page 59 and 60: 50gradation. This allowed for direc
Page 61 and 62: Percent Passing521009080Light 100%
Page 63 and 64: 54percentage of aggregate from the
Page 65 and 66: 56Table 5.4 Summary of Volumetric a
Page 67 and 68: 58Table 5.5 Calculated and Adjusted
Page 69 and 70: 60Table 5.6 Results of APA TestsAir
Page 71 and 72: 62exhibit lower rut depths than any
Page 73 and 74: design had significantly more rutti
Page 75 and 76: 66SP L 100LS SP L 64NS -10.335 2.77
Page 77 and 78: 68percent air voids and percent lim
Page 79 and 80: Air Voids (%)Uncompacted Voids (%)7
Page 81 and 82: 72than the Marshall mixes. Table 6.
Page 83 and 84: Voids in the Mineral Aggregate. As
Page 85 and 86: 76REFERENCESAmerican Association of
Page 87 and 88: 78APPENDIX A BUCKET MIXER INSTRUCTI
Page 89 and 90: 80APPENDIX B FINE AGGREGATE ANGULAR
Page 91 and 92: 82Table B-3 Uncompacted Void Conten
Page 93 and 94: 84AGGREGATE DESIGN DATATable C-1 St
Page 95 and 96: 86Table C-3 Computed Blend Gradatio
Page 97 and 98: 88Table C-7 Marshall Medium 13% NS
Page 99 and 100: 90%G mm%AC VMA VTM VFA @ N ini @N d
Page 101 and 102: 92Table C-14 Superpave Light 64% NS
Page 103: 946 2979.3 1696.7 2988.1 2.307 7.09
Page 106 and 107:
971 2912.7 1620.8 2917.9 2.246 7.65
Page 108 and 109:
992 8.40 10.80 7.402 7.90 9.90 7.80
Page 110 and 111:
1011 9.50 6.90 11.502 9.79 7.15 10.
Page 112 and 113:
1032 8.55 5.20 5.95L R RDate Tested
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Comparison of 9.5 mm SuperPave and Marshall Wearing I Mixes in ...

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