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City of Lincoln
Sampling and Testing Procedures



  1. Asphalt must conform to Chapters 5 and 12 of the 2006 City of Lincoln Standard Specifications.
  2. Plants supplying asphalt for subdivision work must submit mix designs and material samples to the City Testing Lab, for all mix types to be used, at the beginning of each construction season and at least 14 days prior to production as defined in Chapter 12.
  3. Notify the City Testing Lab at the beginning of each day Asphaltic Concrete is to be placed to receive the sampling schedule and to allow for plant material sampling.
  4. Field sampling of Asphaltic Concrete shall be done by the Engineer on a lot basis, at the rate of one sample for each 500 tons placed or fraction thereof per day.
  5. Sample Asphalt from the mat immediately behind the paver prior to rolling. Follow the sampling schedule as close as possible for the sample ton, but do not sample in a radius or other hand work area.
  6. Sample is obtained by extracting two full scoops from the mat with a square-nosed shovel and placing in a double layered, large, paper grocery bag. Penetrate the mat as completely as possible, but do not get into the tack oil or sub-grade below the mat.
  7. Obtain a second sample adjacent to the first sample and give to the Contractor's personnel for correlation testing.
  8. Measure the mat temperature at the sample location at time of sampling.
  9. Record the following information on the bags of both samples:
    1. Date
    2. Sample number
    3. Sample ton
    4. Mat temperature
    5. Lift (e.g. Top, Middle, Bottom)
    6. Lane (e.g. WB-O, West Bound Outside or NB-RT, North Bound Right Turn)
    7. General Location (e.g. Pioneers Blvd., 150' east of 56th)
    8. Stationing and Offset left or right from centerline is also helpful but not required.
  10. Transport the City's sample to the City Testing Lab as soon as possible to maintain heat. Notify the City Testing Lab by phone (441-8407) when in route.
  11. After the rolling process is complete and the mat has cooled mark the location for a density core, in the mat, five to ten feet from the sample location, by painting a box with the sample number inside of it. Make sure that this location does not fall in a radius or hand-work area.

E. ASPHALT (Contd.)

  1. Density cores shall be obtained by the Contractor and delivered to the City Testing Lab as per Chapter 5. If the density core does not meet the required density for 100% pay, the City Testing Lab will notify the Engineer to mark two additional check core locations within five to ten feet either side of the original core. The City Testing Lab will notify the Contractor to obtain and deliver check cores as per Chapter 5.
  2. 14. If density core testing results in pay deductions for any lot, the tonnage of that lot shall be obtained from the Engineer's placement records and the deduct amount calculated from the bid price per ton as per Chapter 5.

Sampling and Testing Procedures