2018 SCDOT Asphalt Specification Changes

SCDOT 2018 Asphalt Specification Changes

Just in this past year there have been a lot of changes to several of the SC Department of Transportation's asphalt specifications. Below is a rundown of the changes, with hyperlinks to each specification. 

SC-T-97 - Method for Verification of Contractor Asphalt Acceptance Test Results (link)

This past month, SCDOT approved and published the latest version of SC T-97, which was modified in conjunction to the changes to SC-M-400.  

SC-M-400 - Asphalt Mixture Quality Acceptance (link)

Major changes to SC-M-400 include but are not limited to:

• Transition from Percent Within Limits (PWL) to closing a day’s production out daily with the use of Absolute Average Deviation (AAD).
  
• Using gradation in lieu of Volumetrics (Air Voids and VMA) for Lot Pay Factor (LPF).
• Volumetrics will be required on the first LOT of a contract for each Job Mix Formula (JMF) & after any mix-test failure.
• Intermediate C – accepted using gauge shots in lieu of cores.
• Mixes that require gauge for in-place density acceptance: one gauge reading per 500-foot section-sublot (formerly 10/LOT).
• All mixes that require cores (Surface Type A-B and Intermediate Type A, B & B-Special) will be taken on a 1 core per 1500-foot section-sublot basis.
• In-place density for cores will be based on average density - not PWL
• Increasing average in-place density to 93.0 - 93.9 to obtain a LPF of 100%
• LPF are no longer weighed if a contractor obtains 105% for Binder Content, 100% for Gradation, and 95% for In Place Density...The LPF is the lowest value...95%.

Contact Cliff Selkinghaus (SelkinghCB@scdot.org) at the SCDOT Office of Materials and Research for a copy of the latest version of the 2018 QA Workbook.

SC-M-402 - Material Properties for Asphalt Mixtures (link)

• Added Intermediate B Special and 
• Allowing either hydrated lime or LASA in mixtures containing PG 64-22.
  

Supplemental Specification: Removal of Existing Asphalt Pavement before Patching 

• Allowing other mix types to be used in FDP based on depth of patches. (link)
• Tables of options for FDP and update to the specification. (link)

SC-M-406 – Liquid Anti-Strip Additives (LASA) for Asphalt Mixtures (link)

The major changes involve:

• Asphalt terminals adding the LASA product to the tanker load during pump out operations
• Allowing LASA in other mix types with PG 64-22.

SCDOT Mix Design Guidelines for Lime to LASA Changes

1% Lime to 0.7% LASA

• Submit a SCDOT 269 form - Same As to LASA, enter the 1% into a dry screening in lieu of hydrated lime to get 100% aggregate blend
• Make 4 ITS/TSR pills and provide results
• Make 2-3 Gyratory pills at optimum binder content and check volumetric properties against original design targets (if not comfortable with target values, then redesign)

• Make 4 ITS/TSR pills and provide results, will show all brands and results on a single JMF

For any additional questions regarding the new changes, please contact Cliff Selkinghaus at the SCDOT Office of Materials and Research.

Email: SelkinghCB@scdot.org
Phone: 803-737-6700