Prime Coat Calculations for IDOT

About a year ago, the Illinois Department of Transportation (IDOT) changed the way it measures & pays for bituminous prime coat. What used to be a simple computation became complicated (just like everything in construction anymore….). The specification requirements were expanded, increasing the degree of surface prep, cleaning & application parameters than with former specifications. IDOT made the change in response to research that has shown the expanded role that prime/tack coats play in the longevity of HMA overlays.

With the new Special Provision (CLICK HERE FOR A COPY), payment calculations also changed. Instead of paying for the total quantity of emulsion applied (in either gallons or pounds of emulsion), IDOT now pays for the residual asphalt (or the actual quantity of bitumen) This requires that the engineer calculate and subtract ALL water (both dilution water AND water in the emulsion) from the volume of material shipped & applied.

OK, so I’m a pretty capable guy. I like to occasionally geek-out on spreadsheets. But for whatever reason, this calculation string was a doosy. Developing formulas, based on the Bill of Lading (as it was shipped to the plant) and then developing respective formulas for the actual delivery was quite tedious. But, with effort comes results. I think I got it.


If you are interested in getting a copy of this worksheet, send me an email link in the COMMENTS below and I’ll try to help you out.



  1. Looks like a great work sheet. Appreciate that you are willing to share it. BTW, your blogs have been very interesting. Great job!

  2. Bob, I am a young Resident Engineer and was referred to your blog from a past manager. I have found the material to be extremely well written and a valuable resource to me. I would really appreciate a copy of this worksheet for it would be a great tool for me in the field. Thank you and I look forward to the blogs to come!

  3. Bob– this is Pat Kielty. I jsut finished DOC course last week and saw Tim Hussey there. Can you sent me a link or copy of your spreadsheet.

  4. Hey, Bob!

    I work in documentation and I would LOVE a copy of your spreadsheet to share with my construction guys and to help me get through this pay item in their reviews.

  5. Hello, Robert. If you could send me a copy of your prime worksheet, I’d appreciate it. Thanks.

  6. Hello Bob,
    You done a great job on the worksheet. Please send me a copy of your worksheet, this will help me out so much. Thank you

  7. Hello Bob,
    You done a good job on creating the worksheet. Please send me a copy of the worksheet. Thank you

  8. Hey Bob, could you send me the spreadsheet? BTW great blog. Its been a great resource for me.

  9. Hey Bob, just stumbled upon your blog, and must say you provide a lot of gems.
    Hope it’s not too late to get a copy of your tack coat spreadsheet. Thank you for sharing.

  10. Thank you for doing this. Could you email me a link to the spreadsheet when time allows?

  11. Could you please email me the link to calculate the tack coat. This will help me final my IDOT project. This is really helpful and thank you for sharing this to us.

  12. Would really appreciate a copy of the worksheet! Your website is awesome, so much great information! Thank you!!

  13. Hi,

    I liked your spreadsheet. I was wondering if you could send a copy(The post age). Also, I love your website.

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