Life-Cycle Cost Analysis of Thin Whitetopping

This report summarizes experiences with thin whitetopping (TWT) in the state of Colorado and provides a model for an economic analysis that justifies selecting TWT for a pavement rehabilitation strategy. Whitetopping is a concrete paving process where new concrete pavement is placed over an existing asphalt pavement. The concrete bonds to the asphalt, resulting in a composite pavement. Properties of both materials are measured or estimated for design. Whereas a typical concrete pavement is placed no thinner than 203 mm (8 in.) in Colorado, TWT is typically place at 152 mm (6 in.) thickness because it derives some support from the asphalt layer. Colorado began experimenting with TWT in 1990. From 1990 to 2003, the Colorado Department of Transportation has placed over 627,095 m(squared) (750,000 yd(squared)) of TWT on 15 different roadways. In 2004, another project with 81,940 m(squared) (98,000 yd(squared)) was placed. This report provides a model for life-cycle cost analysis of the TWT process used in Colorado.