Research results by the National Road Research Alliance (NRRA) and MnDOT show some positive results for early opening of concrete pavements.
MnROAD personnel conducted early life load testing during the test period. This included passage of a ¾-ton pickup approximately 2 hours after placement (to induce visible damage), followed by the movement of an 80,000-lb snow plow the following day.As soon as the pavement was placed and instrumented, the load testing and analysis followed. Bernard Izevbekhai, MnDOT Research Operations Engineer, explains research teams performed early loading in a sequence based on maturity of the concrete. Maturity was calculated or read as a function of internal temperature of the concrete and time.
When the pavement reached 100 degree Celsius-hour (100 °C-Hr.), the trucks were driven on one of four cells (to the edge of the cell), then reversed and back over it again. Likewise, when the maturity reached 200 °C-Hr., a second cell was tested. This proceeded in a similar fashion until all four cells were loaded and tested.
To see videos of the tests follow these YouTube links:
- https://www.youtube.com/watch?v=ZyNy2UA9mSs, and
Click here to read more about the research project. NRRA is a pooled fund program with a mandate to improve the future sustainability of our roads through research and a commitment to cooperative implementation. Special thanks to Matt Zeller of CPAM for sharing this information.