Using Evotherm with Ground Tire Rubber
May 17, 2011
Last Tuesday I attended another very successful project with Chester Bross Construction in on Route 50 in Lee's Summit, MO. This project was a first in several ways for Chester Bross. Not only were they using Evotherm for the first time but this year they purchased a ground tire rubber machine for blending into their PG70-22 asphalt. Evotherm was added using our plant add pump at a rate of 0.4% by weight of AC.
Normally this 12.5mm surface mix with 30% RAP would be produced at 320-330F. The mix was initially produced at this temperature to get all the parts of the plant hot. After 40 tons the temperature was slowly lowered. Paving conditions were ideal for getting the most out of Evotherm with ambient temperatures at 93F and haul time of only 10 minutes. Bag house temperatures were a little slow to rise but once they did asphalt was produced consistently at 240F.
Field conditions were also very favorable for Evotherm with the use of a material transfer device, a brand new Volvo Blaw Knox paver, and 2 brand new high frequency rollers over a milled surface. Mix showed up on-site at 230F. Density readings were between 93 and 95% of the Rice number.
The Chester Bross paving foreman could not believe the temperature of the asphalt coming out behind the screed. The Route 50 job is a huge success for both Evotherm and Chester Bross in Missouri.
Author: Rob Bach