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.