Asphalt 104: An Introduction to Hot Mix Asphalt Materials. -Part II- Mix Design. Scott Shuler CSU

Transcription

1 Asphalt 104: An Introduction to Hot Mix Asphalt Materials -Part II- Mix Design Scott Shuler CSU 1

2 The MIX 2

3 2 The MIX n Rocks

4 2 The MIX n Rocks n Asphalt

5 2 The MIX n Rocks n Asphalt

6 2 The MIX n Rocks n Asphalt n Air

7 2 The MIX n Rocks About 86% n Asphalt n Air

8 2 The MIX n Rocks About 86% n Asphalt n Air

9 2 The MIX n Rocks n Asphalt About 86% About 10% n Air

10 2 The MIX n Rocks n Asphalt About 86% About 10% n Air

11 2 The MIX n Rocks n Asphalt About 86% About 10% n Air 4%

12 2 The MIX n Rocks n Asphalt About 86% About 10% n Air 4%

13 3

14 Purpose of Mixture Design 3

15 To Build Better Roads 3

16 4

17 Better Asphalt Roads are: 4

18 4 Better Asphalt Roads are: A Combination of an Asphalt Binder And Crushed Rocks Medium Coarse Fine

19 5

20 5 These Individual Rock Sizes Will Not Make a Good Asphalt Mix Alone but A Combination Might Medium Coarse Fine

21 6 What Combination Works? Coarse Intermediate Fines

22 6 What Combination Works? Coarse Intermediate Fines 33.3% 33.3% 33.3%

23 7 Maximum Density for Aggregates Goode and Lufsey, Bureau of Public Roads

24 7 Maximum Density for Aggregates Goode and Lufsey, Bureau of Public Roads p = 100 d D 0.45

25 7 Maximum Density for Aggregates Goode and Lufsey, Bureau of Public Roads p = 100 d D 0.45 p = percent material passing a given sieve d D = Maximum aggregate size

26 8 Aggregate Gradation Specs 100 control points Percent Passing maximum density line Nom max size Max size Sieve Sizes Raised to 0.45 Power

27 9

28 What a Mixture Design Does 9

29 9 What a Mixture Design Does Creates a Strong Pavement HOW?

30 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of

31 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks

32 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks

33 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks About 86%

34 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks About 86%

35 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks About 86% n Asphalt

36 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks About 86% n Asphalt

37 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks n Asphalt About 86% About 10%

38 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks n Asphalt About 86% About 10%

39 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks n Asphalt About 86% About 10% n Air

40 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks n Asphalt About 86% About 10% n Air 4%

41 9 What a Mixture Design Does Creates a Strong Pavement HOW? The Right Volumes of n Rocks n Asphalt About 86% About 10% n Air 4%

42 10

43 Traffic Affects the Air Voids 10

44 10 Traffic Affects the Air Voids Rocks

45 10 Traffic Affects the Air Voids Rocks 86%

46 10 Traffic Affects the Air Voids Asphalt Rocks 86%

47 10 Traffic Affects the Air Voids Asphalt 10% Rocks 86%

48 10 Traffic Affects the Air Voids Air Asphalt 10% Rocks 86%

49 10 Traffic Affects the Air Voids Air 4% Asphalt 10% Rocks 86%

50 10 Traffic Affects the Air Voids Air 4% Asphalt 10% Rocks 86%

51 10 Traffic Affects the Air Voids Minivans, Cars Air 4% Asphalt 10% Rocks 86%

52 10 Traffic Affects the Air Voids Heavier Traffic Squeezes Air Out Minivans, Cars Air 4% Asphalt 10% Rocks 86%

53 10 Traffic Affects the Air Voids Heavier Traffic Squeezes Air Out Minivans, Light Trucks, Cars Vans Air 4% 3% Asphalt 10% Rocks 86%

54 10 Traffic Affects the Air Voids Heavier Until There Traffic is Squeezes Less, and Air Less Out Minivans, Light Trucks, Cars Vans Air 4% 3% Asphalt 10% Rocks 86%

55 10 Traffic Affects the Air Voids Heavier Until There Traffic is Squeezes Less, and Air Less Out Minivans, Semis Light Trucks, Cars Vans Air 4% 3% 2% Asphalt 10% Rocks 86%

56 And Finally.. 11

57 11 And Finally.. Rutting

58 12 Adjust Asphalt and Rocks for Traffic Cars Light Trucks Semis Asphalt Air 4% 10% 4% 4% 9% 8% Rocks 86% 87% 88%

59 Simulate Traffic in the Laboratory 13

60 13 Simulate Traffic in the Laboratory Low Gyrations - Cars

61 13 Simulate Traffic in the Laboratory Low Gyrations - Cars

62 13 Simulate Traffic in the Laboratory Low Gyrations - Cars Med Gyrations Lt Trucks

63 13 Simulate Traffic in the Laboratory Low Gyrations - Cars Med Gyrations Lt Trucks

64 13 Simulate Traffic in the Laboratory Low Gyrations - Cars Med Gyrations Lt Trucks High Gyrations - Semis

65 13 Simulate Traffic in the Laboratory Low Gyrations - Cars Med Gyrations Lt Trucks High Gyrations - Semis

66 14

67 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids??????

68 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 Air Voids, % Med Traffic Asphalt, %

69 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 Air Voids, % Med Traffic Asphalt, %

70 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 As Traffic Increases Air Voids, % Low Traffic-35 Med Traffic-50 Hi Traffic Asphalt, %

71 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 As Traffic Increases Air Voids, % Low Traffic-35 Med Traffic-50 Hi Traffic Asphalt, %

72 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 As Traffic Increases Air Voids, % Low Traffic-35 Med Traffic-50 Hi Traffic Asphalt, %

73 14 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 As Traffic Increases Air Voids, % Low Traffic-35 Med Traffic-50 Hi Traffic Asphalt, %

74 The Key to Mixture Design How Much Asphalt to get 4% Air Voids?????? 10 As Traffic Increases Air Voids, % Low Traffic-35 Med Traffic-50 Hi Traffic Decreases Asphalt, % 14

75 15

76 We Must Know Traffic To Know Asphalt % 15

77 15 We Must Know Traffic To Know Asphalt % Let s Design for Residential Street with 100 cars per day

78 15 We Must Know Traffic To Know Asphalt % Let s Design for Residential Street with 100 cars per day

79 15 We Must Know Traffic To Know Asphalt % Air Voids, % Asphalt, % Let s Design for Residential Street with 100 cars per day

80 15 We Must Know Traffic To Know Asphalt % Air Voids, % Low Traffic-35 Let s Design for Residential Street with 100 cars per day Asphalt, %

81 15 We Must Know Traffic To Know Asphalt % Air Voids, % Low Traffic-35 Let s Design for Residential Street with 100 cars per day Asphalt, % 5.7

82 16 Would this Design Work on I-25?????? 10 Low Traffic-35 Air Voids, % Asphalt, %

83 16 Would this Design Work on I-25?????? Air Voids, % Low Traffic-35 Hi Traffic Asphalt, %

84 16 Would this Design Work on I-25?????? Air Voids, % Low Traffic-35 Hi Traffic Asphalt, % NO! 1.8% Air Voids Is Too Low

85 16 Would this Design Work on I-25?????? Air Voids, % Low Traffic-35 Hi Traffic Asphalt, % NO! 1.8% Air Voids Is Too Low Decrease AC%

86 Superpave Mix Design 17

87 17 Superpave Mix Design Gyratory Compactor Simulates Traffic Better Than Hammer

88 17 Superpave Mix Design Gyratory Compactor Simulates Traffic Better Than Hammer

89 17 Superpave Mix Design Gyratory Compactor Simulates Traffic Better Than Hammer Volumetric Analysis (Voids)

90 17 Superpave Mix Design Gyratory Compactor Simulates Traffic Better Than Hammer Volumetric Analysis (Voids)

91 17 Superpave Mix Design Gyratory Compactor Simulates Traffic Better Than Hammer Volumetric Analysis (Voids) Adjusts AC% to Traffic and Climate

92 18

93 Volumetric Analysis 18

94 18 Volumetric Analysis Air Voids

95 18 Volumetric Analysis Air Voids VMA (Voids in Mineral Aggregate

96 18 Volumetric Analysis Air Voids VMA (Voids in Mineral Aggregate VMA Filled with AC%

97 18 Volumetric Analysis Air Voids VMA (Voids in Mineral Aggregate VMA Filled with AC% Absorption

98 VMA Concept 19

99 19 VMA Concept Durability Enough Binder Not Too Much

100 19 VMA Concept Durability Enough Binder Not Too Much n Rocks About 86%

101 19 VMA Concept Durability Enough Binder Not Too Much n Rocks n Asphalt About 86% About 10%

102 19 VMA Concept Durability Enough Binder Not Too Much n Rocks n Asphalt About 86% About 10% n Air 4% VMA = Effective Asphalt + Air Voids are Just Full Enough

103 If VMA Too Low 20

104 If VMA Too Low Durability Suffers Not Enough Coating n Rocks n Asphalt About 88% About 8% n Air 4% VMA = Effective Asphalt + Air Voids are Not Full Enough 20

105 If VMA Too High 21

106 If VMA Too High Stability Suffers Too Much Coating n Rocks n Asphalt About 84% About 12% n Air 4% VMA = Effective Asphalt + Air Voids are Too Full of Asphalt 21

107 22 Select Asphalt and Aggregates Aggregates 1. Coarse Aggregate Angularity (fractured faces) 2. Fine Aggregate Angularity 3. Flat and Elongated Particles 4. Clay Content (sand equivalent) 5. Toughness (LA Abrasion) 6. Soundness 7. Deleterious Stuff 8. Gradation

108 Evaluate Compaction 0 2 Air Voids, % Ndes Nmax Ninit Low Med High Compaction 23

109 24 Stability Load Pressure Rubber Allows Lateral Movement

110 Optimum AC% 25

111 25 Optimum AC% 6 % Voids Stability, % minimum

112 25 Optimum AC% 6 % Voids Stability, % minimum

113 25 Optimum AC% 6 % Voids Stability, % minimum

114 25 Optimum AC% 6 % Voids Stability, % minimum

115 Verify 5.3% AC 26

116 26 Verify 5.3% AC VMA OK?

117 26 Verify 5.3% AC VMA OK?

118 26 Verify 5.3% AC VMA OK? VFA OK?

119 26 Verify 5.3% AC VMA OK? VFA OK?

120 26 Verify 5.3% AC VMA OK? VFA OK? Stability OK?

121 26 Verify 5.3% AC VMA OK? VFA OK? Stability OK?

122 26 Verify 5.3% AC VMA OK? VFA OK? Stability OK? Moisture Sensitivity OK?

123 Let s Pave! 27

124 Let s Pave! 27

125 28