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From page 1... ... 1 I Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA) Read the entire page →
From page 2... ... Table 2 summarizes the information that should be collected for designing WMA mixtures and compares this information to that required for designing HMA mixtures. 2 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Step Description Major WMA Differences 1 Gather Information 1. Read the entire page →
From page 3... ... 3 Type of Information Detail WMA HMA Site Geographic Location X X Climate Relating to Binder Grade X X Design Traffic Level X X Design Life X X Unusual Performance Requirements X X Construction Lift Thickness X X Haul Time X X Construction Temperatures X X Unusual Specification Requirements X X Unusual Construction Requirements X X Pavement Mix Type X X Distance from Pavement Surface X X Aggregate Nominal Maximum Size X X Gradation X X Specific Gravity and Absorption X X Specification Properties X X Binder Performance Grade X X PG Plus Properties, if applicable X X Type of Modification, if applicable X X Continuous Performance Grade for Blending Chart Analysis X X Mixing and Compaction Temperatures NA X RAP Binder Content X X Continuous Performance Grade X X Nominal Maximum Size X X Gradation X X Specific Gravity and Absorption X X Specification Properties X X Anti-Strip Additives Type X X Dosage Rate X X WMA WMA Process X NA Additive Type X NA Additive Dosage Rate X NA Production Temperature X NA Compaction Temperature X NA Table 2. Information required for WMA and HMA design. Read the entire page →
From page 4... ... In NCHRP Project 9-43, several mixtures with less than 1% binder absorption designed as WMA and HMA following the procedures given in this manual had optimum binder contents and volumetric properties that were essentially the same. The recommended design compaction levels for both WMA and HMA 4 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Read the entire page →
From page 5... ... Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA) 5 Virgin Binder PG Grade 58-28 58-22 64-22 64-16 67-22 Average HMA Production Temperature, oF 285 285 292 292 300 Rate of Improvement of Virgin Binder LowTemperature Grade per oC Reduction in Plant Temperature 0.035 0.025 0.025 0.012 0.025 WMA Production Temperature, oF Recommended Improvement in Virgin Binder LowTemperature Continuous Grade for RAP Blending Chart Analysis, oC 300 NA NA NA NA 0.0 295 NA NA NA NA 0.1 290 NA NA 0.0 0.0 0.1 285 0.0 0.0 0.1 0.0 0.2 280 0.1 0.1 0.2 0.1 0.3 275 0.2 0.1 0.2 0.1 0.3 270 0.3 0.2 0.3 0.1 0.4 265 0.4 0.3 0.4 0.2 0.5 260 0.5 0.3 0.4 0.2 0.6 255 0.6 0.4 0.5 0.2 0.6 250 0.7 0.5 0.6 0.3 0.7 245 0.8 0.6 0.7 0.3 0.8 240 0.9 0.6 0.7 0.3 0.8 235 1.0 0.7 0.8 0.4 0.9 230 1.1 0.8 0.9 0.4 1.0 225 1.2 0.8 0.9 0.4 1.0 220 1.3 0.9 1.0 0.5 1.1 215 1.4 1.0 1.1 0.5 1.2 210 1.5 1.0 1.1 0.5 1.3 205 1.6 1.1 1.2 0.6 1.3 200 1.7 1.2 1.3 0.6 1.4 Table 3. Read the entire page →
From page 6... ... The lower temperatures for WMA mixtures result in less binder absorption compared with HMA. In NCHRP Project 9-43, the binder absorption for WMA mixtures was about 90% of that for HMA 6 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Application Recommended NMAS, mm Minimum Lift Thickness, mm Fine-Graded Mixtures Coarse-Graded Mixtures Leveling course mixtures 4.75 15 to 25 20 to 25 9.5 30 to 50 40 to 50 Wearing course mixtures 4.75 15 to 25 20 to 25 9.5 30 to 50 40 to 50 12.5 40 to 65 50 to 65 Intermediate course mixtures 19.0 60 to 100 75 to 100 25.0 75 to 125 100 to 125 Base course mixtures 19.0 60 to 100 75 to 100 25.0 75 to 125 100 to 125 37.5 115 to 150 150 Rich base course mixtures 9.5 30 to 50 40 to 50 12.5 40 to 65 50 to 65 Table 5. Read the entire page →
From page 7... ... % VA = design air voids, vol. % Gsb = aggregate bulk specific gravity Pwa = water absorption of the aggregate, weight % As with HMA mixture design, the binder content by volume computed at this point is an estimate that will be refined during Step 10, Evaluate and Refine Trial Mixtures, of the design process. Read the entire page →
From page 8... ... Note that the aggregate specification requirements apply to the blended aggregates and should be measured on the final design blend of aggregates. For trial batches, they can be 8 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Design ESALs (million) Read the entire page →
From page 9... ... These calculations are performed automatically by HMA Tools and when RAP is included in the mixture, binder from the RAP is properly accounted for in the calculations. WMA mixtures should meet the requirements for the ratio of dust to effective binder content given in Chapter 8 for HMA. Read the entire page →
From page 10... ... Viscosity-based mixing and compaction criteria cannot be used with the wide range of WMA 10 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Step Description HMA WMA Comment 1 Calculate batch weights X X Must calculate WMA additive content for some processes 2 Batch aggregates X X Must batch WMA additive for some processes 3 Heat aggregates and asphalt binder X X Use planned production temperature for WMA 4 Mix aggregates and binder X X Procedure is WMA process specific 5 Mixture conditioning X X WMA uses lower temperature 6 Compact laboratory specimens X X WMA uses lower temperature 7 Calculate volumetric composition of laboratory specimens X X 8 Adjust aggregate proportions to meet volumetric requirements X X 9 Evaluate coating and compactability NA X Used in WMA design in place of viscositybased mixing and compaction temperatures 10 Conduct performance testing X X Moisture sensitivity for all mixtures, rutting resistance for design traffic levels of 3 m ESALs or greater procedures Table 12. Comparison of trial specimen fabrication procedures for WMA and HMA design. Read the entire page →
From page 11... ... Bucket mixers are less efficient than planetary mixers; therefore, the mixing times may need to be increased. For WMA processes requiring the additive to be blended in the binder, a low-shear mechanical stirrer with appropriate size impeller is needed to homogeneously blend the additive in the binder. Read the entire page →
From page 12... ... Determine the target total weight of the mixture where wt = target total weight wi = oven dry weight from Step a Pbnew = % by weight of total mix of new binder in the mixture c. Add new binder to the bowl to reach wt w w p t i bnew = − ⎛⎝⎜ ⎞⎠⎟1 100 12 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Read the entire page →
From page 13... ... The coarse aggregate and dry portion of the fine aggregate are mixed with the binder at normal HMA production temperatures. The percentage of the fine aggregate that will be added wet, the moisture content of that portion of the fine aggregate, and the initial mixing temperature are recommended by the WMA process supplier. Read the entire page →
From page 14... ... Determine the target total weight of the mixture: where wt = target total weight wi = oven dry weight from Step a wdwf = oven dry weight of the wet fraction from the batch sheet Pbnew = percent by weight of total mix of new binder in the mixture c. Determine the target weight of the heated mixture: w w wthm t dwf= − w w w p t i dwf bnew = +( ) Read the entire page →
From page 15... ... It should be between 90 and 100°C. Foamed Asphalt The preparation of foamed asphalt mixtures requires special asphalt binder foaming equipment that can produce foamed asphalt using the amount of moisture that will be used in field production. Read the entire page →
From page 16... ... WMA mixtures for both volumetric mixture design and mechanical property testing (performance evaluation) should be conditioned for 2 hours at the planned compaction temperature. Read the entire page →
From page 17... ... are used to perform the volumetric analysis. Air Void Content where VA = Air void content, volume % Gmb = Bulk specific gravity of compacted mixture Gmm = Maximum theoretical specific gravity of loose mixture Total Binder Content by Volume where VB = Total asphalt binder content, % by total mix volume Pb = Total asphalt binder content, % by mix mass Gmb = Bulk specific gravity of the mixture Gb = Specific gravity of the asphalt binder Absorbed Binder by Volume where VBA= Absorbed asphalt content, % by total mixture volume Gmb = Bulk specific gravity of the mixture Pb = Total asphalt binder content, % by mix mass Gb = Specific gravity of the asphalt binder Ps = Total aggregate content, % by mix mass, equal to 100 − Pb Gsb = Average bulk specific gravity for the aggregate blend Gmm = Maximum specific gravity of the mixture Effective Binder Content by Volume where VBE = Effective asphalt content, % by total mixture volume VB = Asphalt binder content, % by mix volume VBA = Absorbed asphalt content, % by total mixture volume VBE VB VBA= − ( ) Read the entire page →
From page 18... ... Adjust Aggregate Proportions to Meet Volumetric Requirements Adjusting WMA mixtures to meet volumetric requirements is the same as discussed in Chapter 8 for HMA. The procedure presented in this manual is designed to provide acceptD B P Pbe = 0 075. Read the entire page →
From page 19... ... The sections that follow describe these evaluations. Coating Coating is evaluated at the planned production temperature by preparing loose mix of the design mixture following the specimen fabrication procedures presented earlier and evaluating the coating of the coarse aggregate particles using AASHTO T 195, Standard Method of Test for Determining Degree of Particle Coating of Bituminous-Aggregate Mixtures. Read the entire page →
From page 20... ... Performance evaluation for WMA is the same as HMA and includes evaluation of the resistance to moisture damage for all mixtures and evaluation of rutting resistance for mixtures designed for traffic levels of 3 million ESALs and higher. As discussed above, the primary difference between WMA and HMA is in mixture conditioning -- HMA mixtures are conditioned for 4 hours at 135°C, whereas WMA mixtures for performance testing are conditioned at the planned compaction temperature for 2 hours. Read the entire page →
From page 21... ... In such cases, the following information should be included in the report: • The organization that performed the mix design • The name of the technician or engineer responsible for developing the mix design I Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA) Read the entire page →
From page 22... ... , the nominal maximum aggregate size, the design traffic level, the Ndesign value, and any special requirements • Complete aggregate information, including for each aggregate the producer, the size designation of the aggregate, gradation, specific gravity, and all applicable specification properties • Binder information, including the binder PG grade and the name of the supplier • Composition of the mixture, including the design air void content, the design VMA, the design VBE, the mineral filler content, the target dust/binder ratio and the estimated unit weight for the mix • The planned production and compaction temperatures • The results of the evaluation of coating • The results of the compactability analysis • The results of moisture resistance testing • The results of rut resistance testing, if applicable (generally for mixtures designed for traffic levels of 3 million ESALs and over) HMA Tools includes a comprehensive mix design report that contains all of this information and additional information on the results of trial mixtures evaluated during the mix design process. Read the entire page →
From page 23... ... The recycling additive has a specific gravity of 1.020 and is to be added at 1.00% by total mix weight. After entering the binder grading data in HMA Tools, the blended binder grade is given as a PG 64-22, with an intermediate grading temperature of 25°C. Read the entire page →
From page 24... ... (Note that the component weights are not percentages but are in units 24 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Aggregate Wt. % in Aggregate Blend No. Read the entire page →
From page 25... ... 25 Mix Component Percent by Total Mix Volume Bulk Specific Gravity Percent by Aggregate Weight Percent by Total Mix Weight Air 4.00 -- - -- - -- - New Asphalt Binder 7.34 1.026 -- - 3.19 RAP Asphalt Binder 3.37 1.030 -- - 1.47 Liquid Antistrip Additive 0.066 1.020 -- - 0.028 Recycling Additive 2.31 1.030 -- - 1.00 No. 67 Stone 16.67 2.635 20 18.86 1B Stone 20.81 2.639 25 23.58 Screenings 7.90 2.771 10 9.43 Manufactured Sand 12.36 2.630 15 14.15 RAP Aggregate 25.13 2.619 30 28.29 Note: Calculations may not agree exactly because of rounding. Read the entire page →
From page 26... ... A Note on Using HMA Tools to Perform WMA Mix Designs HMA Tools has several features designed specifically for use in designing WMA. In worksheet "General," there is a section for entering information generally required for WMA, such as production and compaction temperature, and whether or not to allow adjustment in the low-temperature grade of the virgin binder. Read the entire page →
From page 27... ... Using the Asphalt Mixture Performance Tester (AMPT) Other Publications Bonaquist, R., "Mix Design Practices for Warm Mix Asphalt," NCHRP Report 691, National Cooperative Highway Research Program, Washington, D.C., 2011. Read the entire page →

From page 1...

... 1 I Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA)

Read the entire page →

From page 2...

... Table 2 summarizes the information that should be collected for designing WMA mixtures and compares this information to that required for designing HMA mixtures. 2 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Step Description Major WMA Differences 1 Gather Information 1.

Read the entire page →

From page 3...

... 3 Type of Information Detail WMA HMA Site Geographic Location X X Climate Relating to Binder Grade X X Design Traffic Level X X Design Life X X Unusual Performance Requirements X X Construction Lift Thickness X X Haul Time X X Construction Temperatures X X Unusual Specification Requirements X X Unusual Construction Requirements X X Pavement Mix Type X X Distance from Pavement Surface X X Aggregate Nominal Maximum Size X X Gradation X X Specific Gravity and Absorption X X Specification Properties X X Binder Performance Grade X X PG Plus Properties, if applicable X X Type of Modification, if applicable X X Continuous Performance Grade for Blending Chart Analysis X X Mixing and Compaction Temperatures NA X RAP Binder Content X X Continuous Performance Grade X X Nominal Maximum Size X X Gradation X X Specific Gravity and Absorption X X Specification Properties X X Anti-Strip Additives Type X X Dosage Rate X X WMA WMA Process X NA Additive Type X NA Additive Dosage Rate X NA Production Temperature X NA Compaction Temperature X NA Table 2. Information required for WMA and HMA design.

Read the entire page →

From page 4...

... In NCHRP Project 9-43, several mixtures with less than 1% binder absorption designed as WMA and HMA following the procedures given in this manual had optimum binder contents and volumetric properties that were essentially the same. The recommended design compaction levels for both WMA and HMA 4 Special Mixture Design Considerations and Methods for Warm Mix Asphalt

Read the entire page →

From page 5...

... Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA) 5 Virgin Binder PG Grade 58-28 58-22 64-22 64-16 67-22 Average HMA Production Temperature, oF 285 285 292 292 300 Rate of Improvement of Virgin Binder LowTemperature Grade per oC Reduction in Plant Temperature 0.035 0.025 0.025 0.012 0.025 WMA Production Temperature, oF Recommended Improvement in Virgin Binder LowTemperature Continuous Grade for RAP Blending Chart Analysis, oC 300 NA NA NA NA 0.0 295 NA NA NA NA 0.1 290 NA NA 0.0 0.0 0.1 285 0.0 0.0 0.1 0.0 0.2 280 0.1 0.1 0.2 0.1 0.3 275 0.2 0.1 0.2 0.1 0.3 270 0.3 0.2 0.3 0.1 0.4 265 0.4 0.3 0.4 0.2 0.5 260 0.5 0.3 0.4 0.2 0.6 255 0.6 0.4 0.5 0.2 0.6 250 0.7 0.5 0.6 0.3 0.7 245 0.8 0.6 0.7 0.3 0.8 240 0.9 0.6 0.7 0.3 0.8 235 1.0 0.7 0.8 0.4 0.9 230 1.1 0.8 0.9 0.4 1.0 225 1.2 0.8 0.9 0.4 1.0 220 1.3 0.9 1.0 0.5 1.1 215 1.4 1.0 1.1 0.5 1.2 210 1.5 1.0 1.1 0.5 1.3 205 1.6 1.1 1.2 0.6 1.3 200 1.7 1.2 1.3 0.6 1.4 Table 3.

Read the entire page →

From page 6...

... The lower temperatures for WMA mixtures result in less binder absorption compared with HMA. In NCHRP Project 9-43, the binder absorption for WMA mixtures was about 90% of that for HMA 6 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Application Recommended NMAS, mm Minimum Lift Thickness, mm Fine-Graded Mixtures Coarse-Graded Mixtures Leveling course mixtures 4.75 15 to 25 20 to 25 9.5 30 to 50 40 to 50 Wearing course mixtures 4.75 15 to 25 20 to 25 9.5 30 to 50 40 to 50 12.5 40 to 65 50 to 65 Intermediate course mixtures 19.0 60 to 100 75 to 100 25.0 75 to 125 100 to 125 Base course mixtures 19.0 60 to 100 75 to 100 25.0 75 to 125 100 to 125 37.5 115 to 150 150 Rich base course mixtures 9.5 30 to 50 40 to 50 12.5 40 to 65 50 to 65 Table 5.

Read the entire page →

From page 7...

... % VA = design air voids, vol. % Gsb = aggregate bulk specific gravity Pwa = water absorption of the aggregate, weight % As with HMA mixture design, the binder content by volume computed at this point is an estimate that will be refined during Step 10, Evaluate and Refine Trial Mixtures, of the design process.

Read the entire page →

From page 8...

... Note that the aggregate specification requirements apply to the blended aggregates and should be measured on the final design blend of aggregates. For trial batches, they can be 8 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Design ESALs (million)

Read the entire page →

From page 9...

... These calculations are performed automatically by HMA Tools and when RAP is included in the mixture, binder from the RAP is properly accounted for in the calculations. WMA mixtures should meet the requirements for the ratio of dust to effective binder content given in Chapter 8 for HMA.

Read the entire page →

From page 10...

... Viscosity-based mixing and compaction criteria cannot be used with the wide range of WMA 10 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Step Description HMA WMA Comment 1 Calculate batch weights X X Must calculate WMA additive content for some processes 2 Batch aggregates X X Must batch WMA additive for some processes 3 Heat aggregates and asphalt binder X X Use planned production temperature for WMA 4 Mix aggregates and binder X X Procedure is WMA process specific 5 Mixture conditioning X X WMA uses lower temperature 6 Compact laboratory specimens X X WMA uses lower temperature 7 Calculate volumetric composition of laboratory specimens X X 8 Adjust aggregate proportions to meet volumetric requirements X X 9 Evaluate coating and compactability NA X Used in WMA design in place of viscositybased mixing and compaction temperatures 10 Conduct performance testing X X Moisture sensitivity for all mixtures, rutting resistance for design traffic levels of 3 m ESALs or greater procedures Table 12. Comparison of trial specimen fabrication procedures for WMA and HMA design.

Read the entire page →

From page 11...

... Bucket mixers are less efficient than planetary mixers; therefore, the mixing times may need to be increased. For WMA processes requiring the additive to be blended in the binder, a low-shear mechanical stirrer with appropriate size impeller is needed to homogeneously blend the additive in the binder.

Read the entire page →

From page 12...

... Determine the target total weight of the mixture where wt = target total weight wi = oven dry weight from Step a Pbnew = % by weight of total mix of new binder in the mixture c. Add new binder to the bowl to reach wt w w p t i bnew = − ⎛⎝⎜ ⎞⎠⎟1 100 12 Special Mixture Design Considerations and Methods for Warm Mix Asphalt

Read the entire page →

From page 13...

... The coarse aggregate and dry portion of the fine aggregate are mixed with the binder at normal HMA production temperatures. The percentage of the fine aggregate that will be added wet, the moisture content of that portion of the fine aggregate, and the initial mixing temperature are recommended by the WMA process supplier.

Read the entire page →

From page 14...

... Determine the target total weight of the mixture: where wt = target total weight wi = oven dry weight from Step a wdwf = oven dry weight of the wet fraction from the batch sheet Pbnew = percent by weight of total mix of new binder in the mixture c. Determine the target weight of the heated mixture: w w wthm t dwf= − w w w p t i dwf bnew = +( )

Read the entire page →

From page 15...

... It should be between 90 and 100°C. Foamed Asphalt The preparation of foamed asphalt mixtures requires special asphalt binder foaming equipment that can produce foamed asphalt using the amount of moisture that will be used in field production.

Read the entire page →

From page 16...

... WMA mixtures for both volumetric mixture design and mechanical property testing (performance evaluation) should be conditioned for 2 hours at the planned compaction temperature.

Read the entire page →

From page 17...

... are used to perform the volumetric analysis. Air Void Content where VA = Air void content, volume % Gmb = Bulk specific gravity of compacted mixture Gmm = Maximum theoretical specific gravity of loose mixture Total Binder Content by Volume where VB = Total asphalt binder content, % by total mix volume Pb = Total asphalt binder content, % by mix mass Gmb = Bulk specific gravity of the mixture Gb = Specific gravity of the asphalt binder Absorbed Binder by Volume where VBA= Absorbed asphalt content, % by total mixture volume Gmb = Bulk specific gravity of the mixture Pb = Total asphalt binder content, % by mix mass Gb = Specific gravity of the asphalt binder Ps = Total aggregate content, % by mix mass, equal to 100 − Pb Gsb = Average bulk specific gravity for the aggregate blend Gmm = Maximum specific gravity of the mixture Effective Binder Content by Volume where VBE = Effective asphalt content, % by total mixture volume VB = Asphalt binder content, % by mix volume VBA = Absorbed asphalt content, % by total mixture volume VBE VB VBA= − ( )

Read the entire page →

From page 18...

... Adjust Aggregate Proportions to Meet Volumetric Requirements Adjusting WMA mixtures to meet volumetric requirements is the same as discussed in Chapter 8 for HMA. The procedure presented in this manual is designed to provide acceptD B P Pbe = 0 075.

Read the entire page →

From page 19...

... The sections that follow describe these evaluations. Coating Coating is evaluated at the planned production temperature by preparing loose mix of the design mixture following the specimen fabrication procedures presented earlier and evaluating the coating of the coarse aggregate particles using AASHTO T 195, Standard Method of Test for Determining Degree of Particle Coating of Bituminous-Aggregate Mixtures.

Read the entire page →

From page 20...

... Performance evaluation for WMA is the same as HMA and includes evaluation of the resistance to moisture damage for all mixtures and evaluation of rutting resistance for mixtures designed for traffic levels of 3 million ESALs and higher. As discussed above, the primary difference between WMA and HMA is in mixture conditioning -- HMA mixtures are conditioned for 4 hours at 135°C, whereas WMA mixtures for performance testing are conditioned at the planned compaction temperature for 2 hours.

Read the entire page →

From page 21...

... In such cases, the following information should be included in the report: • The organization that performed the mix design • The name of the technician or engineer responsible for developing the mix design I Special Mixture Design Considerations and Methods for Warm Mix Asphalt (WMA)

Read the entire page →

From page 22...

... , the nominal maximum aggregate size, the design traffic level, the Ndesign value, and any special requirements • Complete aggregate information, including for each aggregate the producer, the size designation of the aggregate, gradation, specific gravity, and all applicable specification properties • Binder information, including the binder PG grade and the name of the supplier • Composition of the mixture, including the design air void content, the design VMA, the design VBE, the mineral filler content, the target dust/binder ratio and the estimated unit weight for the mix • The planned production and compaction temperatures • The results of the evaluation of coating • The results of the compactability analysis • The results of moisture resistance testing • The results of rut resistance testing, if applicable (generally for mixtures designed for traffic levels of 3 million ESALs and over) HMA Tools includes a comprehensive mix design report that contains all of this information and additional information on the results of trial mixtures evaluated during the mix design process.

Read the entire page →

From page 23...

... The recycling additive has a specific gravity of 1.020 and is to be added at 1.00% by total mix weight. After entering the binder grading data in HMA Tools, the blended binder grade is given as a PG 64-22, with an intermediate grading temperature of 25°C.

Read the entire page →

From page 24...

... (Note that the component weights are not percentages but are in units 24 Special Mixture Design Considerations and Methods for Warm Mix Asphalt Aggregate Wt. % in Aggregate Blend No.

Read the entire page →

From page 25...

... 25 Mix Component Percent by Total Mix Volume Bulk Specific Gravity Percent by Aggregate Weight Percent by Total Mix Weight Air 4.00 -- - -- - -- - New Asphalt Binder 7.34 1.026 -- - 3.19 RAP Asphalt Binder 3.37 1.030 -- - 1.47 Liquid Antistrip Additive 0.066 1.020 -- - 0.028 Recycling Additive 2.31 1.030 -- - 1.00 No. 67 Stone 16.67 2.635 20 18.86 1B Stone 20.81 2.639 25 23.58 Screenings 7.90 2.771 10 9.43 Manufactured Sand 12.36 2.630 15 14.15 RAP Aggregate 25.13 2.619 30 28.29 Note: Calculations may not agree exactly because of rounding.

Read the entire page →

From page 26...

... A Note on Using HMA Tools to Perform WMA Mix Designs HMA Tools has several features designed specifically for use in designing WMA. In worksheet "General," there is a section for entering information generally required for WMA, such as production and compaction temperature, and whether or not to allow adjustment in the low-temperature grade of the virgin binder.

Read the entire page →

From page 27...

... Using the Asphalt Mixture Performance Tester (AMPT) Other Publications Bonaquist, R., "Mix Design Practices for Warm Mix Asphalt," NCHRP Report 691, National Cooperative Highway Research Program, Washington, D.C., 2011.

Read the entire page →

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