405— Open-Graded Friction Course

400-29 Section 405 — Open- Graded Friction Course

405.1 Description 1 Construct a permeable open- graded friction course (OGFC), mixed in an approved asphalt plant. 405.2 Materials 405.2.1 General 1 Use materials meeting the applicable requirements of Subsection 401.2, except as modified in this Subsection. Do not use RAP, slag, or marine limestone in the OGFC. PG 76 -22 and hydrated lime are required. 405.2.2 Aggregate 1 Use crushed coarse aggregate having an abrasion loss of not more than 52.0% when tested according to AASHTO T 96 (C Grading). If the aggregate abrasion loss is greater than 42.0% but less than or equal to 52.0% , test the Micro- Deval abrasion value of the material according to AASHTO T 327 and ensure it does not exceed a maximum of 15.0% loss. Use crushed coarse aggregate with two or more freshly mechanically induced fractured faces on at least 90.0 %, based on count, according to AASHTO T 61, and a Sodium Sulfate Soundness loss not greater than 15.0% when subjected to five alterations according to AASHTO T 104. When fly ash is used as a mineral filler material in an OGFC design, ensure that it is from a source listed on Qualified Products List 3. 405.2.3 Additives 1 Use a chemical additive that is listed on Qualified Products List 77 and is terminally blended with the asphalt binder. The use of stabilizing fibers is not required. 405.2.4 Composition of Mixture 1 Submit a job mix formula according to SC-T-88. Ensure that job mix formulas are accepted by the AME before use on Department work. Ensure that the job mix formulas are prepared in a laboratory accepted by the AME according to SC-M-405 and by technicians certified as a SCDOT Level 2 Asphalt Mix Technician. Ensure a minimum retention coating of 99.5% following SC-T-91. Ensure that the abrasion resistance (Cantabro) of the OGFC mixture is less than 15.0% using SC-T-127. Ensure that porosity measurements o n the job mix formula specimens are equal to or greater than 13.0 % according to SC-T-128. Design and set target job mix formula gradations within the master range listed