Dense graded rubber mixtures and chemkrete (81-09-1)
Abstract
This report discusses the application of three ground
rubber additives and a chemical additive as ingredients in
dense graded asphalt concrete (AC) overlays. A two inch layer
of Type C dense graded AC vith fabric reinforcement io being
used as a comparison.
The goal of this project is to find better methods of
controlling distress cracking and to slow the deterioration of
the AC overlay.
The construction methods for each product mixture are
discussed. The Cbemkrete method closely resembles conventional
mixing and laying methods. A chemical agent was added to the
asphalt holding tank and thoroughly mixed. Ground tire rubber
crumbs of the Arm-R-Shield and Overflex processes were added
and mixed with 85-100 penetration asphalt. The Plusride
product ia also ground tire rubber but is added as an
aggregate. Fabric reinforcement was not used with the asphalt
rubber mixes.
ln this experimental application, one and one-half inches
of Chemkrete costs about the same as two inches of AC. Two
inches of Plusride cost about twice the standard AC.
Arm-R-Shield and Overflex cost about 3 1/2 times the standard AC
for their respective 2 inch layers.
Evaluations of the performance of these products will
continue for three years. Initial performance evaluations
indicate some stress conditions are beginning to come into
view.