Road Widening Included
The construction project was also to be used to simultaneously widen the roadway to 4.40 m (14 feet 5 inches). “To this end, we initially milled off 60 cm (2 feet) along the inner edge of the roadway that borders the passing lane," said Mike Crenshaw, president of the contractor King Asphalt, Inc. from Liberty, South Carolina, explaining the steps taken to prepare the road using two Wirtgen cold milling machines. Only then could the cold recycling train, led by the W 380 CRi, get rolling. The tracked cold recycler milled the damaged pavement at a width of 3.80 m (12 feet 6 inches) and a depth of 20 cm (8 inches) in a single pass. In the process, it simultaneously granulated the material while mixing in 2.3% foamed bitumen, 1% pre-spread cement, and 3 – 4% water.
Binding Agents Create Permanent Stability
“In FDR, stabilizing the layers recycled with foamed bitumen gives the sub-base the structural strength it needs to withstand recurring loads over decades of use,” explained Mark Stahl, director of recycling products for the Wirtgen Group in North America.