The National Road Research Alliance (NRRA) is hosting “Performance Benefits of Fiber-Reinforced Thin Concrete Pavement and Overlays” on September 21 at 10 a.m. CST, presented by Manik Barman, University of Minnesota Duluth.
The NRRA’s monthly seminar highlights research topics that will make an impact on the work done here in the state of Minnesota and around the country.
Due to increasing budget constraints, there is interest in economizing pavement structures by reducing the panel thickness or increasing the service life of the pavement. Past research has demonstrated definite limits to reducing the panel thickness of conventional undoweled jointed plain concrete pavement (JPCP), thus invoking interest in understanding the potential of using structural fiber-reinforced concrete (FRC) to either allow slab thickness reduction or an increase in service life. The research need arises in understanding the contribution of structural fibers in mitigating panel fatigue cracking and transverse joint faulting in thin concrete overlays and pavement on grade. There is interest in understanding the effects fiber reinforced concrete have on panel size as well, especially for much thinner slabs.
Structural fibers generally improve the performance of thin concrete pavement and overlays by (i) holding cracks tight and (ii) transferring the wheel load between adjacent slabs. Several laboratory studies are currently in progress to comprehensively quantify the above-mentioned two benefits. Performance comparison of companion pavement sections (with and without fibers) are now required to obtain a field-validated method to accurately account for the contribution of fibers for the future mechanistic-empirical (ME) design procedures of FRC based thin concrete overlays and pavements on grade.
To achieve this, the National Road Research Alliance (NRRA) has designed and constructed seven fiber-reinforced concrete test cells and one control plain concrete cell at the MnROAD facility in summer 2017. The primary variables in these cells include panel thickness, type of support (base), panel size, and fiber dosage. All of these cells are equipped with different types of response measuring sensors. Performance of these cells will be periodically evaluated. Sensor data and periodically collected performance data will be used to achieve the following objectives:
- Determining contribution of fibers in reducing panel fatigue cracking;
- Determining contribution of fibers in mitigating joint faulting;
- Determining optimal panel size.