As a part of sustainable construction, pervious concrete has been found to be a better choice over traditional asphalt pavements. Because of higher voids content, pervious concrete allows water to percolate in the ground reducing the storm water runoff and helping ground water table to recharge. Reduction in runoff has a major advantage of reducing harmful waste and contaminants getting transported to nearby water bodies such as lakes and rivers.  Pervious concrete is typically used in areas with light traffic such as parking lots and walkways. Despite its benefits, pervious concrete has not been used widely in cold climates owing to its potential susceptibility to freeze-thaw, salt, and clogging. 

The Trinity parking lot on the UVM Campus is first of its kind in Vermont. It is half traditional asphalt and half pervious concrete, and the pervious concrete portion is comprised of removable slabs made by Porous Technologies, LLC. These slabs can be lifted and cleaned, and replaced if desired, as part of maintenance.  

In order to monitor the functioning of pervious concrete, a variety of instrumentation has been placed around and under the parking lot. The pervious concrete pavement is supposed to allow the stormwater to infiltrate through the soils underneath as if there was no pavement. The embedded instrumentation is expected to examine this desired performance. Lysimeters are being used to collect water samples to allow assessment of water quality. The moisture probes measure electrical conductivity which is an indicator of changes in moisture content, salt concentration and temperature fluctuations.  The pore pressure transducers measure fluctuations in groundwater below different portions of the pavements and nearby. In addition to the embedded instrumentation, a rain gauge and temperature sensors are installed outside to capture all the rain events and monitor temperature fluctuations. In addition, the infiltration capacity of the pervious concrete will also be monitored using a falling head infiltrometer over the next two years and the goal is to relate the measured infiltration to maintenance and cleaning practices. 

The research is being conducted in collaboration with the School of Engineering. The sensor measurements and their analysis will be incorporated in some civil and environmental engineering courses at UVM. In fact, a preliminary plan for the instrumentation was developed by a team of civil and environmental engineering seniors as part of their capstone project, which also included preliminary design of this parking lot. The entire study is funded by UVM's Transportation & Parking and the United States Department of Transportation through UVM's Transportation Research Center. The research team is comprised of Prof. Mandar Dewoolkar [Mandar.Dewoolkar@uvm.edu], Dr. Lalita Oka and Ian Anderson.