820Asphalt Cement

820.1General Description

This section includes the requirements for asphalt cements prepared from crude petroleum. 820.1.01 Related References

General Provisions 101 through 150.

Standard Operating Procedure (SOP 4) AASHTO R 28 AASHTO T 48 AASHTO T 179 AASHTO T 240 AASHTO T 313 AASHTO T 314 AASHTO T 315 AASHTO T 316 AASHTO TP70 / ASTM D7405

820.2Materials

820.2.01 Asphalt Cement

Type Use a material homogenous and water-free and will not foam when heated to 347 °F (175 °C). Ensure blend used to produce a specified performance grade meets the following requirements: • Is uniform and homogeneous without separation • Uses PG 64-22 or PG 67-22 described below for the base asphalt • Consists of production materials not being “air-blown”. • Contains < 0.5% acid (including Polyphosphoric Acid (PPA) modification, when approved by the Office of Materials. Grade Use the various grades of asphalt cement meeting the requirements shown in the test requirements for Petroleum Asphalt Cements. Add Styrene-Butadiene-Styrene (SBS) or Styrene-Butadiene (SB) to neat asphalt to produce a binder meeting requirements for PG 76-22 when roadway ADT is equal to or greater than 100,000 for Stone Matrix Asphalt and Porous European Mix (PEM) or Open Graded Friction Course (OGFC) Mixtures. Styrene Butadiene Rubber (SBS) or Crumb rubber modified PG 76-22 is an acceptable alternative to SBS or SB modified asphalt cement at contractor’s discretion, when roadway ADT is less than 100,000, provided the SBR or crumb rubber modified asphalt cement meets the tests’ requirements of PG 76-22. For SBR modified PG 64-22 or PG 67-22 to meet PG 76-22, use only SBR currently approved on QPL-65 “Georgia’s List of 1503 1503 1503

Approved Latex Suppliers”. For crumb rubber modified PG 64-22 or PG 67-22 to meet PG 76-22, use 30 mesh size ambient or cryogenic ground tire rubber at minimum 10% of weight of total asphalt cement content. Ensure Trans-Polyoctenamer is added at 4.5% of the weight of the crumb rubber to achieve better particle distribution. Varying percentage blends of crumb rubber and approved additives may be used, at the discretion of the Office of Materials, provided the end product meets all specified requirements of PG76-22 including Phase Angle. Ensure the end product is homogenous and shows no separation or coagulation. Percentage of ambient or cryogenic ground tire rubber is neat asphalt source dependent to meet specification requirements for PG 76-22. The maximum Phase Angle requirement is not applicable to the crumb rubber modified PG 76-22 incorporating ≥ 10% crumb rubber with approved additive equivalent to 4.5% of crumb rubber (see notes f, g, i and j). TEST REQUIREMENTS FOR PETROLEUM ASPHALT CEMENTS Test and Method Test Temperature Original Binder Residue of Binder After: PG (Note e) PG 64- PG PG (Note d) Rolling Thin Film Oven, AASHTO: T 240 Pressure Aging AASHTO: R 28 Flash Point, Min., AASHTO T 48 446 °F (230 °C) Viscosity, Max., AASHTO T 316, (Note a) 275 °F (135 °C) 3Pa-S (3000C P) Mass Loss (%), Max., AASHTO T 240, (Note b) 0.5 Dynamic Shear, G*/sin δ, AASHTO T 315, 10 Rad/Sec 136 °F (58 °C) 147 °F (64 °C) 153 °F (67 °C) 169 °F (76 °C) > 1.0 kPa > 2.2 kPa Dissipated Energy, Dynamic Shear, G*sin δ, AASHTO T 315, 10 Rad/Sec 72 °F (22 °C) 77 °F (25 °C) 80 °F (26.5 °C) 88 °F (31 °C) < 5000 kPa Creep Stiffness, 60 sec., AASHTO T 313, (Note c) 10 ° F (- 12 °C) S < 300 000 kPa m > 0.300 1504 1504 1504

Test and Method Test Temperature Original Binder Residue of Binder After: Direct Tension, 1.0 mm/min., AASHTO T314, Failure Strain 10 ° F (- 12 °C) Report Multiple Stress Creep & Recovery

D7405, AASHTO TP70 (proposed), Jnr 3.2 kPa, (Notes f, g, i and j) 64 °C < 1.0 Polymer Separation Test ASTM D7173 AASHTO T53 Softening Point (ºF) (ºC) [h] (< 18 ºF) (< 10 ºC) Difference between top and bottom specimens Notes:

pumped and mixed at temperatures meeting all applicable safety standards.

is ≥300,000 kPa, report the Direct Tension Failure Strain value. Satisfy the m-value requirement in either case.

(Section 424).

combination modified PG 76-22 asphalt cement. Additionally, ensure the materials meet all PG 76-22 requirements except for phase angle as detailed in sub-section 820.2.01.A.2.

blended PG 64-22 or PG 67-22 modified using SBR or GTR to meet PG 76-22 requirements.

using complete analysis for compliance with PG 76-22 requirements prior to mixture production using laboratory blended materials. PG 64-22 or PG 67-22 modified to meet PG 76-22 using crumb rubber via dry method, will be evaluated for compliance with original DSR testing requirements for PG 76-22 during mixture production using abson recovery in accordance with GDT 119 in compliance with AC sampling frequencies established in GSP 21 sub-section A.9.

evaluated for MSCR (Jnr @ 3.2 kPa) requirements, in accordance with GDT 119, on AC samples obtained for project assurance at frequencies established in GSP 21 sub-section A.9. 1505 1505 1505

Thoroughly blend the composite materials at the supply facility prior to being loaded into the transport vehicle if modification is required in accordance with 820.2.01. Ensure all blending procedures, formulation, and operations are approved by the Office of Materials. Certification: Provide certified test results from an approved, certified laboratory of blends for proposed PG asphalt for each specification characteristic of the asphalt cement proposed for shipment. Provide the certified results to the State Materials Engineer as required in Standard Operating Procedure (SOP 4). The State Materials Engineer may interrupt production until test results are known in the event there is reason to suspect a sample will be outside specification limits. Mixture placed incorporating modified binders determined to not meet specification requirements may be subject to removal at the recommendation of the State Materials Engineer.

General Provisions 101 through 150. 1506 1506 1506