Here's the back-up for my statement:
" State transportation officials blamed the failure on a key ingredient in concrete. When it was built, there was a shortage in the natural resin used in highway concrete, the stuff that adds bubbles and helps it withstand big swings in temperatures, Richard said. That’s because more of it was being sold to the cosmetic industry, he said. He said that forced the industry to use synthetic resin, which hadn’t been perfected. "
From http://woodtv.com/2016/04/26/m-6-crumbling-years-ahead-of-schedule/
This would be part of the " additives for special situations" you mention. Seems to be a key ingredient in cold weather states to accommodate the freeze-thaw cycle.
Honestly, this is the last post about road/highway construction in the wrong thread.