- 841 - SECTION 1029 -- PERFORM ANCE GRADED BINDER
1029.01 Description
1.Performance Graded (PG) binder shall conform to the requirements of AASHTO M332 Table 1. PG binder sha ll also conform to the Department PG+ specifications (Table 1029.01) wh en classified as a modified binder.
a.The test of Direct Tension, AASHTO M332 Table 1, is omitted.
b.The test of J nrdiff, AASHTO M332 Table 1, is omitted.
2.The Performance Graded Binder shall be supplied by a supplier that is certified by the Department.
a.A supplier may request certification by contacting the Nebraska Department of Transportation, Materials and Research Division, Flexible Pavement Engineer.
b.A certified supplier must furnish a quality control program to the Department Bituminous Laboratory for review and approval. The program shall follow, at a minimum, the guidelines of AASHTO R26 with references to AASHTO M320 to include AASHTO M332.
c.A certified supplier must be a participant in one or more of the following PG Binder Groups: (1) AASHTO Materials Reference Laboratory (AMRL) (2) Western Cooperative Testing Group (WCTG) (3) Combined States Binder Group (CSBG) (4) A PG Binder round robin Group approved by the Department
d.A certified supplier must maintain, meet and follow the requirements of the group or groups in which they participate, to maintain certification by the Department. In additi on, active participation is required to maintain certification by the Department. Active participation will include submitting of round robin sample results.
1.For suppliers that desire to provide product while approved PG Binder Group membership is pending, a temporary certification may be issued for a period of up to one year. Split sample testing will be required prior to receiving a temporary ce rtification. Split sample testing will be done on all grades of binder that t he supplier intends to supply during the temporary certification period. The supplier will have up to one year to become certified by participating in an d following the requirements of one or more of the approved PG Binder Groups , and to meet all other conditions for certification.
e.A certified supplier may be a sked to supply to the Department: past round robin results, laboratory inspection reports, reasons for and investigative reports on outlying resu lts, quality control testing results, technician training and/or pr oficiency testing reports.
f.A certified supplier will agree to inspection of their plant or terminal without notice anytime during pr oduction or supplying of material to the Department. The inspection may also include the supplier’s laboratory.
g.If desired, a certified supplier can voluntarily submit samples of PG binder proposed for use to the Department Materials and Research
1029.01 Performance Graded Binder
- 842 - Bituminous Laboratory for courtesy testing prior to Asphalt production. The test results will be for Information-Only.
h.Certification will be withdr awn from a supplier when one or more of the following conditions exist:
1.Inability to consistently supply material meeting specifications as outlined herein.
2.Failure to maintain an acceptable quality control program. (3) The failure to meet one or more of the conditions of being a certified supplier as outlined, but not limited to only these conditions.
i.Notification of decertification of a supplier will be submitted in writing by the Department. The notific ation will include the reason(s) why decertification occurred. PG Binders from a decertified source will not be accepted for use on Department projects.
j.If a supplier has lost certif ication and seeks to be recertified, the following steps are required:
1.Supplier shall fulfill the requirements outlined above for gaining Certified Supplier status. This may include the submittal of material samples to ensure specifications compli ance before recertification approval.
2.Supplier shall submit documentation to the Department Flexible Pavement Engineer explaining the cause(s) of decertification outlined in the notification, and the acti ons that are being taken to correct the problem(s) identified by the Department.
1029.02 Material Characteristics
1.Modified Performance Grade binders shall meet the following specifications:
a.All specified binders with a grade temperature spread of 92 oC or greater, shall be defined as modified.
b.The PG Binder shall meet the Multiple Stress Creep Recovery (MSCR) specifications of the following Table: Table 1029.01 PG+ Specifications AASHTO T350 MSCR Average Percent Recovery @ 3.2 kPa for modified PG binders AASHTO M332 Performance Grade Test Temperature of oC 58S – 34 --- 58H - 34 30 Min. 58V - 34 55 Min. 58E - 34 75 Min.
c.The binder shall incorporate a blend of base asphalt and the use of the elastomer modifiers styrene-butadiene (SB), styrene-butadiene-styrene (SBS), or styrene- butadiene-rubber (SBR).
1.Polyphosphoric Acid (PPA) may be used as an additional modifier to elastomer modifiers and shall not exceed 0.50% maximum PPA Performance Graded Binder 1029.03 - 843 - addition (by weight of binder). The total phosphorous content of the PPA- modified PG Binder shall not exceed 1900 ppm. The total phosphorous content shall be determined as per ASTM D1091, ASTM D6443, or ASTM D6481.
i.To determine specifications compliance, the Department requires a sample of the base asphalt binder, a sample of the PPA, and supplier-prepared varying PPA percentage modified binder samples. These samples shall be se nt to the Department Bituminous Laboratory prior to project Asphalt production.
2.Crumb rubber may be used as an additional modifier to elastomer modifiers. If crumb rubber is used:
i.Paragraph 5.4 (solubility) of AASHTO M332 is then void. (ii) Paragraph 5.5 (micron requirement) of AASHTO M332 is then void.
d.The composite material shall be thoroughly mixed at the asphalt refinery or terminal prior to (for tank storage) or as (in-line blending) being loaded into the transport vehicle.
1.The modified binder shall be heat and storage stable and shall not separate when handled and stored as per the supplier’s recommendations.
2.The composite material shall be homogenous, and shall not demonstrate evidence of localized gelation or over-crosslinking of polymers. The composite material shal l not otherwise contain any other non- homogenous conglomerations.
2.Unmodified Performance Grade Binders are defined as specified binders with a grade temperature spread of less than 92oC.
1029.03 Procedure
1.A Material Certification shall be submitted to the Engineer prior to construction or when switching supplier s, stating the type of any modifier(s) being used. The Material Certification mu st also state that the material has not been air blown or oxidized.
a.If the PG Grade modification process of the PG Binder includes the use of PPA (Polyphosphori c Acid) and/or crumb rubber, then the Material Certification must also stat e the type of all modifiers used in the formulation. If PPA is used, the Material Certification must state the percent PPA in the binder, and also state and co nfirm the total phosphorous content of the PPA modified binder.
2.The Contractor shall receive fr om the supplier, instructions on the proper storage and handling of each grade and shipment of PG Binder.
3.Substitution of a PG Binder, wh ich exceeds the upper and/or lower grade designations from what is specif ied, requires adv ance notification to, and approval by, the Engineer. The substitution of the PG Binder shall also be identified in the sample identification submittals.
1029.03 Performance Graded Binder
- 844 - 4. PG Binder Lots and their re spective samples are defined as follows:
a.Each 200 tons of liquid PG Binder grade incorporated into the production of Asphalt, or final portion thereof, will be a binder lot.
b.A binder lot will include only one PG Binder grade, or will include a blend of grades as defined in paragraph 5.
c.A binder lot will include only one supplier of the PG Binder. (1) If a Contractor needs to switch binder suppliers during the production of a binder lot, it is the C ontractor’s responsibility to ensure both the compatibility and the specifications compliance of the mixture of the respective binder products. The suppli er designation of the lot will be listed as “mixed suppliers” if the binder lot sample was taken after this occurs.
d.The Engineer must be notifi ed and approve of the intent to blend binder grades, or to switch binder suppliers, prior to either occurrence.
e.All binders shall be sampled at the rate of at least one sample per binder lot.
1.The sample shall consist of a two-quart (half gallon) can and shall be taken by the Contractor's Certified Sampling Technician, with confirmation by Department personnel. The sample shall be taken at the plant from the line between the storage t ank and the mixer, or from the tank supplying material to the line, at a location from which material sampled is representative of the materi al in the line to the mixer. The sampling process shall follow procedures of the Depart ment’s Materials Sampling Guide.
2.When the tested PG Binder is in compliance, the binder lot will be accepted and the sample will be discarded. If the tested PG Binder does not comply, then the pay factor of the PG Binder lot represented by the sample shall be adjusted according to Table 1029.02, and Table 1029.03 (if modified).
3.When a total PG Binder grade type on a project is less than 200 tons, a minimum of one PG Binder lot sample is required. If the PG Binder does not comply with test sp ecifications, then the pay factor of the PG Binder lot shall be adjusted according to Table 1029.02, and Table
1029.03 (if modified).
5.Blending of differing PG Binder grades at the hot mix plant site will be allowed only with prior approval, and with the following restrictions:
a.The resultant blend of grades will meet PG+ (if modified binder), and/or AASHTO M332 specificat ions when tested as ±3° C of the specified PG Binder grade.
b.The sample of the blended material will be considered as a lot sample, and it will be taken during initial production following the blending of the binders.
c.The lot sample of the blended material shall have a pay factor applied as per Table 1029.02, and Table 1029.03 (if modified), when not meeting specifications.
d.The blended sample's id entification form shall note the blending conditions and provide a statem ent that the sample is a blend of grades. Performance Graded Binder 1029.03 - 845 - e. The next lot sample, following the sample representing the blend, will be tested as the specifi ed binder grade for the asphalt mixture being produced and shall meet AASHTO M332 and PG+ (if modified), specifications.
f.For modified PG Binders, only blending of the same type of elastomer modifiers listed in 1029.02 Paragraph 1.c. will be allowed.
6.The Nebraska Department of Transportation, Materials and Research Bituminous Laboratory, will do selective testing on each Binder Lot. When any test result shows a lot sa mple not meeting s pecifications, that lot sample and any adjacent previous, and any adjacent following lot sample received will be tested for complete specifications compliance. Adjacent lot sample testing will then continue in th is manner until tested samples meet all specifications, or there are no more lot samples remaining to be tested.
1029.03 Performance Graded Binder
- 846 - 7. All lot samples as tested are s ubject to the Pay Factors listed in Table 1029.02, and also Table 1029.03 if modified, below: Table 1029.02 Tests of AASHTO M332 Pay Factor Table 1 Test and Specification Test Results Pay Factor Original Binder Dynamic Shear, G*/Sin , kPa Min. 1.00 > 0.99 1.00 0.97 - 0.99 0.95 0.94 - 0.96 0.90 0.91 - 0.93 0.85 < 0.91 0.70 or Reject Rolling Thin Film Oven Residue, Standard Traffic “S”, MSCR Jnr3.2 Max. 4.5 kPa-1 <4.6 1.00 4.6 .95 4.7 .90 4.8 .85 >4.8 .70 or Reject Rolling Thin Film Oven Residue, Heavy Traffic “H”, MSCR Jnr3.2 Max. 2.0 kPa-1 <2.1 1.00 2.1 .95 2.2 .90 2.3 .85 >2.3 .70 or Reject Rolling Thin Film Oven Residue, Very Heavy Traffic “V”, MSCR Jnr3.2 Max. 1.0 kPa-1 <1.1 1.00 1.1 .95 1.2 .90 1.3 .85 >1.3 .70 or Reject Rolling Thin Film Oven Residue, Very Heavy Traffic “E”, MSCR Jnr3.2 Max. 0.5 kPa-1 <0.6 1.00 0.6 .95 0.7 .90 0.8 .85 >0.8 .70 or Reject Pressure Aging Vessel Residue Dynamic Shear, “S”, G* sin , kPa Max. 5000 < 5001 1.00 5001 - 5200 0.95 5201 - 5400 0.90 5401 - 5600 0.85 > 5600 0.70 or Reject Pressure Aging Vessel Residue Dynamic Shear, “H”, “V”, “E”, G* sin , kPa Max. 6000 < 6001 1.00 6001 – 6050 .95 6051 – 6100 .90 6101 – 6150 .85 >6150 .70 or Reject Performance Graded Binder 1029.03 - 847 - Test and Specification (cont’d) Test Results Pay Factor Pressure Aging Vessel Residue BBR m-Value Min. 0.300 >0.350 1.05 0.300 – 0.350 1.00 0.295 – 0.299 0.95 0.290 – 0.294 0.90 0.285 – 0.289 0.85 <0.285 0.70 or Reject Pressure Aging Vessel Residue BBR Creep Stiffness, mPa Max. 300 < 200 1.05 200 - 300 1.00 301 - 310 0.95 311 - 320 0.90 321 - 330 0.85 > 330 0.70 or Reject Table 1029.03 PG + Pay Factor Table 1 AASHTO T350 Multiple Stress Creep Recovery (MSCR) @ 58oC Test and Specifications Test Results Pay Factor AASHTO M332 Performance Grade 58H-34 Average Percent Recovery @ 3.2 kPa Min. 30% > 29 1.00 29 0.95 28 0.90 27 0.85 < 27 0.70 or Reject AASHTO M332 Performance Grade 58V-34 Average Percent Recovery @ 3.2 kPa Min. 55% > 54 1.00 54 0.95 53 0.90 52 0.85 < 52 0.70 or Reject AASHTO M332 Performance Grade 58E-34] Average Percent Recovery @ 3.2 kPa Min. 75% > 74 1.00 74 0.95 73 0.90 72 0.85 < 72 0.70 or Reject Pressure Aging Vessel Residue BBR Creep Stiffness, mPa Max. 300 < 200 1.05 200 - 300 1.00 301 - 310 0.95 311 - 320 0.90 321 - 330 0.85 > 330 0.70 or Reject 1 If a lot sample has more than one test that results in a reduced pay factor (less than 1.00) from either or both of the above Pay Factor Tables, the single largest pay factor reduction will be the one used in determining the lot pay factor. If a lot sample passes all testing (1.00 or greater), and one or more test pay factors are 1.05, the pay fa ctor of 1.05 will be the one used in determining the lot pay factor.
1029.03 Performance Graded Binder
- 848 - 8. When all lot samples have been received and tested, a final pay factor of all the PG Binder per Asphalt type will be calculated and applied as follows:
a.The final pay factor is the av erage of all lot sample pay factors. The final pay factor cannot exceed 1.000. Example Calculations: 4 Binder Lots Asphalt: 0.95 + 1.05 + 1.00 + 0.85 4 = 0.962 Final Pay Factor 3 Binder Lots Asphalt: 0.95 + 1.05 + 1.05 3 = 1.017 = Final Pay Factor of 1.000
b.The final pay factor will be a pplied to the contract unit price of asphalt binder.
c.The Engineer will determine if lo ts that have a test pay factor of 0.70 or Reject will be removed. If 0.70 or Reject material is left in place, a price factor of 0.70 will be the determin ed lot pay factor. The final pay factor will be applied to the contract unit price of asphalt binder.
1.Removal and replacement will be at no additional cost to the Department.
2.If any lot was removed, a new lot pay factor will be determined by testing of the replacement material.
9.When the testing of a PG binder lot sample shows test results that are outside of specification limits, the initial process of resolving the sample failure will include the following actions, as appropriate:
a.The Department Bituminous Laboratory may conduct retesting of the remaining portion of the sample as determined necessary to confirm the original test result(s).
b.The Department Bituminous Laboratory will notify the Department project personnel, who will in turn notify the Contractor. All parties will arrange to investigate all aspe cts of the testing, loading, handling and delivery of the material in question. The Contractor and Department project personnel shall report their findings to the Bituminous Laboratory.
c.The Department Bituminous Laboratory will collect and compile all information provided.
d.The Department Bituminous Laboratory will issue a standard report of tests for all samples tested, to include any resulting final pay factor deductions or removals. A copy of the report of tests will be distributed to the District and the Construction Division. The District will then provide a copy to the Contractor. PG Binder Supplier requests for a copy of this report will be directed to the Contractor.
10.If the Contractor wishes to dispute any results after testing and investigations have been completed on any failing lot sample(s) that subjected the final pay factor from paragraph 8 to less than 1.000, the Department will select an independent la boratory for referee testing to take place on the remaining portion of the sample(s). Performance Graded Binder 1029.03 - 849 - a. Only the Contractor can init iate dispute resolution, and request referee testing. The request must be made, in writing, to the Department Construction Division within 30 days of awareness of final pay factor determination. Otherwise disput e resolution is forfeited.
b.The identity of the indepen dent laboratory will not be revealed until the selected laboratory has comple ted the referee testing, and the Department Bituminous Laboratory has submitted a final report of the results.
c.If the independent lab's tests indicate failing results and pay deductions equal to or greater than the Department’s, the Contractor will reimburse the Department for the cost of testing. If the independent lab's tests indicate that the material meets s pecification, or is at a pay deduction less than the Department’s, the Department will assume the cost of testing. When the independent lab's tests indicate a pay deduction, the lesser of the Department’s and the independent lab's deductions will be applied. - 850 - SECTION 1030 -- LIQUID ASPHALTS
1030.01 Description
1.Medium-Curing Cutback Asphalt is the accepted Department’s liquid asphalt.
1030.02 Material Characteristics
1.Cutback asphalts shall conform to t he AASHTO M 82, Medium- Curing Type requirements with the following changes:
a.Note “a” of Table 1 is void. b. Note “b” of Table 1 is amend ed to read: In lieu of viscosity of the residue, the Department specifie s the test of penetration with a specification of 120 to 250 dmm for all grades.
c.Due to the advent of low-sulfur petroleum formulations, some of which are used as diluent in the fluxing of cutback materials production, the Table 1 test requirements of Flash Point (tag, open cup), and Distillation, percent by volume of total distillate at the temperatures of 225 oC (437oF) and 260oC (500oF), are removed.
1030.03 Procedures
1.Medium-Curing cutback as phalts shall be stored, heated, transferred, or otherwise handled, as per Manufacturer’s recommendations.
1030.04 Acceptance Requirements
1.Liquid asphalts will be accepted as described in the Department’s Materials Sampling Guide .
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 875–883 of 1,048.