Synthesis of Current Minnesota Practices of Thin and Ultra-Thin Whitetopping

Status: Complete
Report Date: 07/22/2005

Summary:

This report documents the current practices of Minesota in rehabiliting Hot Mix Asphat pavement with thin and ultra-thin Portland cement concrete overleys, i.e. thin and ultra-thin whitetopping. The current practices of thin whitetopping (TWT) in Minnesota and its adjacent states have shown that TWT has been used successfully and is an important alternative for rehabilitating HMA pavements of medium volume roads. If designed and constructed properly, TWT is also an important alternative for rehabilitating HMA pavements of highway volume roads with more requirements in HMA quality, bonding and fiber reinforcement. The performance of ultra-thin whitetopping (UTW) projects in Minnesota ranges from very good to failing. The sections that perform poorly are short sections under stopping trucks or buses and over thin or poor condition HMA pavement. UTW has been used successfully in Minnesota when inlaid into thick and sound HMA pavements even in high-volume traffic. The quality of the HMA substrate, bonding, fiber reinforcement, and joint spacing all significantly affect the success of UTW. The great caution should be used when rehabilitating HMA pavements at bus stops, weigh stations, and intersections. The Minnesota Department of Transportation (Mn/DOT) does not recommend UTW for major highways and heavy traffic areas.

Final Deliverables:

Synthesis #2005-27