MnROAD Cell 54: Cell Constructed With Mesabi-Select (Taconite-Overburden) Aggregate; Construction and Early Performance

Cell 54 was constructed on October 22, 2004 on the straight portion of the MnROAD low-volume loop coterminous with the curved portion on the south-east side. It is made up of 8-inches of concrete underlain by variable depth of class 5 aggregate base and approximately 3 in. of compacted in-situ fill. Mn/DOT constructed thus cell to study properties of Mesabi-Select as aggregate in Concrete. This mineral aggregate that contains less iron than the ore, was obtained from overburdens in the iron ore ledges in northern Minnesota. There is no record of a previous cell constructed to study the suitability of Mesabi-Select in concrete. This project consisted of a 192-ft jointed-plain-dowelled concrete pavement comprising two lanes of 12- by 15-ft slabs paved by slip-form construction process on October 22, 2004. The longitudinal joints were tied and unsealed. Mn/DOT obtained samples and laboratory tested them for mechanical properties after rheological properties had been field evaluated. The inside lane and the outside lane will be loaded with the standard MnROAD 80-kip and 110-kip truck in the same frequency and load spectrum as other parts of the load volume road. Performance data will be continuously obtained from embedded strain gauges, vibrating wires, moisture sensors and thermocouples.