Illinois Tollway Goes Fiber Free
Aug 06, 2012
Curran Contracting and William Charles have been hard at work on Illinois Tollway I-88 East. They are producing SMA without fibers and with Evotherm for this 220,000 ton job. The mix is an IL 12.5mm N80 SMA Friction Wearing Course along with 12% Fractionated RAP, 5% RAS, and Evotherm. Curran’s DeKalb, IL, location produces the mix through their counterflow plant at about 260 tons per hour. The production temperature has been about 50 degrees F lower than their standard production temperatures for SMA's and dense graded mixes.
A test strip determined that 14-16 passes produced the best density, keeping in mind that IDOT does not allow vibration on the SMA mixes and all passes were static. The mix looked and rolled great yielding in-spec volumetrics, passing field Hamburgs, and densities ranging from 94%-97%. All parties involved have been pleased with the outcome.
The tollway work is ongoing so take notice if you are driving down the Illinois Tollway on fiberless, warm-mix SMA.
Author: Jason Mapes