Akkari, Alexandra

Pervious pavement provides a solution for many highly developed urban areas where an excessive amount of contaminated water is diverted into storm and sewer systems and left untreated before entering natural water sources such as rivers and streams. By allowing water to flow through the pavement surface and infiltrate the underlying soil, pervious pavements can reduce the amount of this pollution. Test cells were constructed at MnROAD to be monitored for drainability to evaluate the possibility of using pervious pavements to mitigate this problem. Other important criteria influencing the performance of pervious concrete in pavements will also be monitored, including mechanical and structural properties, surface characteristics, noise, and durability. This document summarizes the research that went into Report 2011-23, "Pervious Concrete Test Cells on MnROAD Low-Volume Road.."

This report examines how full-depth colored concrete performs in Minnesota roadways, and includes recommendations for improved specifications for construction and for repair of existing installations.

In September 2011 MnDOT constructed two cells in the MnROAD Mainline in continuation of the study of unbonded overlay (Cell 5) and to facilitate studies on a drainable base (Cell 6) with a longitudinal tined texture. Additionally, roller-compacted concrete shoulders were constructed in these cells to replace the preexisting asphalt shoulders. Finally, repairs were done to a thin concrete overlay of existing asphalt pavement installed in 2004 (Cell 63). This report discusses the construction procedure, instrumentation and the initial monitoring from these test cells.

This report summarizes the construction and early performance assessment of three composite (new, multi-layer, construction) test cells at the MnROAD: HMA over a recycled aggregate concrete; diamond grind concrete over recycled aggregate concrete; and exposed aggregate concrete over a low cost concrete. The compilation of this report is strictly a MnDOT activity that documents construction and instrumentation of concrete cells at our MnROAD facility and should not be misconstrued for a SHRP 2 activity. Strength, on board sound intensity, sound absorption, friction, texture and international roughness index were tested to better understand the performance of these, pavement types. Results suggest that the exposed aggregate concrete surface does not provide significant noise reduction. Exposed aggregate surfacing can provide more than adequate friction for skid resistance and safety. Overall, however, these two lift concrete pavements proved to address issues such as high cost of virgin aggregates and high trucking costs for areas that don't have quality aggregates to use. Continued monitoring of these test cells will help develop the extensive understanding of composite pavements needed for effective design and accurate service life models.

Local agencies are interested in pervious pavements ability to reduce storm water runoff by allowing direct infiltration through the pavement structure. However, concerns about the ability of pervious pavements to perform in Minnesota's extreme climate, maintenance needs, and effect on groundwater quality needed to be understood. This report includes the design, construction, and early performance of three pervious concrete test cells construction at MnROAD in 2008. These cells were constructed to evaluate the performance of pervious concrete pavements on a low-volume road in a cold weather climate. The three cells discussed in this report are as follows: porous concrete overlay, pervious concrete on granular subgrade, pervious concrete on cohesive subgrade. This report has the following chapters, which uniquely discuss each phase of this project: research synthesis; mix design, concept design, and geotechnical exploration; construction sequence; initial testing; hydrologic evaluation; early two year performance; implementation; effect of sound absorption on OBSI; and acoustic properties of clogged pavements.

A need arose at the MnROAD research facility to provide a thin beam structural overlay on a moderately deteriorated concrete pavement test cell. This research was done to evaluate a polyvinyl alcohol fiber reinforced engineered cementitious composite (PVA-ECC) and assess the prospects to utilize the material in the bonded pavement overlay. PVA-ECC is a ductile material that can achieve extremely high flexural strength and tensile strain capacity, characteristics which can prevent reflective cracking in pavement. The PVA-ECC mix was tailored by including coarse aggregate to maintain some of the benefits of typical concrete pavements. Workability, flexural and compressive strength, ductility and durability tests were done to assess the performance at varying fiber contents. Results show that fiber at 16 lbs/cy achieved the highest flexural and compressive strength, at 1030 and 6910 psi respectively. The paired student's t-test shows that 16 lbs/cy of fiber can improve flexural strength by between 150 and 300 psi with 95% confidence. This small increase and lack of any noticeable ductile behavior do not make the PVA-ECC beneficial for overlay applications. This research found that the modified PVA-ECC with the low doses of fiber examined in this study are not suitable for the overlay at MnROAD.