MnDOT Research

A completed LRRB-funded study is helping engineers better understand and reduce surface tenting, a type of pavement distress caused by frost and moisture under the roadway. Researchers identified causes of tenting, evaluated pavement treatments and created new tools to help engineers choose the best maintenance options.

Mitigating Surface Tenting to Improve Road Quality Transverse cracking and tenting are significant problems for asphalt pavements, especially in colder climates where the asphalt layer contracts during winter conditions. While the impacts of frost …

Concrete roundabouts are becoming more common across Minnesota and understanding their performance is essential for long-term safety and durability. A new MnDOT & LRRB-funded study will evaluate concrete roundabout designs statewide to identify pavement distress and the influence of design features such as joint spacing, dowel bar placement, and drainage features. The findings will help improve design practices and extend pavement life.

New Project: Are Current Rigid Pavement Roundabout Designs Working in Minnesota? As roundabouts become more commonplace in Minnesota, the role they play in the improvement of traffic flow and safety increases. Although rigid roundabouts were originally designed with the assumpt…

Minnesota is home to over 30,000 stormwater ponds and historic wetlands that help keep phosphorus and other pollutants out of lakes and rivers. A completed LRRB-funded study examined the functions of stormwater treatment systems and identified the most effective strategies to remove phosphorus. Results showed that street-sweeping, chemical treatment, and mechanical aeration are among the strategies that help lower phosphorus levels.

Reducing Phosphorus Pollution from Ponds Ponds and historic wetlands are essential for preventing excessive phosphorus from reaching downstream waters. These systems remove solids, nutrients, metals and hydrocarbons from stormwater runoff…

Using recycled asphalt pavement (RAP) materials can lower costs, reduce environmental impacts, and conserve natural resources. However, there is little information on how well RAP mixtures compact. In a completed LRRB-funded study, researchers evaluated asphalt mixtures with different RAP content and explored whether adding graphite nanoplatelets could enhance compaction. Results showed that mixtures with higher RAP contents can still compact well and perform reliably in cold weather.

Evaluating Recycled Asphalt Pavement Mixtures The use of recycled asphalt pavement (RAP) materials in asphalt pavement construction provides numerous benefits, including reduced material costs, fewer environmental impacts and decreased demand …