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

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57among the tests results of the same mixture was also observed and examined during and afterthe APA testing.5.3.1 Procedure for Determining Sample Weights for Correct Air VoidsThe procedure for the APA test was fairly straightforward. First, the weight of sample for 7 0.5percent air voids was estimated using Equation 5.3.VsampWest GmmC1[5.3]C2Where,W est = estimated weight to achieve 7.0% air voidsG mm = maximum theoretical specific gravity of specific mixtureV samp = volume of APA sample with height of 75mm = 1325.3mm 3C 1 = percent sample of total volume at 7.0% voids = 0.93C 2 = constant observed in lab accounting for voids at sample surface = 1.03.Estimated weights were calculated for each mix design with the above equation and trial blendswere made up. It was found that these weights resulted in the air voids being just slightly over7.5 percent in some of the mixes. If a mix was within range but very close to either limit then itwas adjusted also to reduce the effects of having to reject a sample that went above or belowthe limits due to variability in the mix. Most of the mixtures required adding 20 g to theestimated weight to achieved the proper air content. Table 5.5 contains the calculated andadjusted weights for each mix design.The next step in preparing for the APA samples was the making of the required number ofspecimens for proper testing of each mix design. In the preliminary stages of this research itwas decided that three samples of each mix design would be necessary to correctly test the mixdesigns. A sample would consist of two specimen pills each, making a total of 6 specimen pillsper mix design and with 12 mix designs that number comes to 72 pills required. The sampleswere blended, mixed and compacted in accordance with the particular specimen’s mix designmethod with the exception of using the gyratory compactor for the compaction of Marshallspecimens. Since samples were tested randomly in the APA, testing could not begin until allsamples had been made.
58Table 5.5 Calculated and Adjusted Weights for APA Test SamplesMix DesignCalculatedWeightAdjustedWeightMR HVY 100% LS 2978 2998MR MED 100% LS 2969 2989MR HVY 13% NS 2946 2956MR MED 13% NS 2941 2951SP HVY 100% LS 2971 2991SP MED 100% LS 2956 2976SP HVY 13% NS 2975 2995SP MED 13% NS 2966 2986SP LOW 100% LS 2966 2986SP LOW 50% NS 2910 2930SP LOW 64% NS 2910 2930SP LOW 100% LS (mod) 2988 30085.3.2 Test ProcedureOnce all the APA samples were compacted to the proper height of 75mm and air content ofbetween 6.5 and 7.5 percent, the APA tests were performed. The tests were conducted byrandomly testing two specimens of each mix design in a random position in the testing tray. Tobegin, each specimen was placed into the specimen retaining molds and secured in the testingtray in the proper positions. Once the testing tray was secured in the APA, the soak time andtemperature was set at 3 hours and 140 F, respectively. Pressing the start button then startedthe automated testing process. After the three-hour soak time, hoses pressurized to 100 psiwere automatically lowered unto the samples. Then wheels loaded to 100 pounds werelowered onto the hoses and the repetitive loading process started. This process consisted of8000 cycles of the wheels rolling back and forth across the hoses and specimens. The APAautomatically shut down once it completed these cycles and the samples were allowed to cool.Once the samples were cool and removed from the APA, a measuring template was placed overthe sample retaining mold and a deflectometer was passed over two equally spaced positionson each specimen pill making a total of four measurements per sample. After measurements
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 and 54: 44Mechanical Laboratory Sieve. Afte
Page 55 and 56: Percent Passing4610090100% Limeston
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: 56Table 5.4 Summary of Volumetric a
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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