- Prediction of Thermal Behaviors of Pervious Concrete Pavements in Winter
- Monday, May 15, 2017 - 9:00AM Alaska Time
- Civil & Environmental Engineering
- Washington State University
In-field thermal performance of pervious concrete pavements during the winter was investigated in this project because this behavior affects winter safety and mobility of drivers/pedestrians. The amount of heat conducted through pervious concrete is affected by the highly voided structure of pervious concrete. Therefore, it is critical to establish the thermal conductivity (k) of pervious concrete to predict those times during the winter that the surface nears freezing temperatures and ice/snow control actions may be required. In a combined field-laboratory investigation, this project included an analysis of the field temperature data from an instrumented pervious concrete pavement (PCP) sidewalk in Pullman, WA. Based on the data collected during winter 2016 when ambient temperature ranged 0-60°F, the sidewalk surface did remain at freezing temperatures for a cumulative duration of 24 days. In order to build upon the field data for theoretical modeling, k of pervious concrete at variable volumetric air void (porosity) was experimentally characterized using two different methods. Conductivity of pervious concrete was found in 0.50-0.62 W/(mK) range as opposed to 2.13-3.29 W/(mK) range for limestone and quartzite aggregate traditional concrete. Because air has a low k of 0.024 W/(mK), conductivity of pervious concrete is lower than the reported values for impermeable concrete with minimal entrapped air. A basic parallel model was proposed for estimating k of pervious concrete based on the mixture proportioning and k of individual constituents. The value of k for the instrumented sidewalk when used in a temperature prediction simulation model provided close agreements between the predicted and in-field temperatures at near-surface depths of the instrumented sidewalk.
Dr. Nassiri is an Assistant Professor at the Civil & Environmental Engineering Department of Washington State University. Dr. Nassiri’s main research thrust centers around sustainable material and design solutions for concrete infrastructure. One of the focus areas of Dr. Nassiri’s research over the last two years has been directed at putting forward solutions for the several emerging challenges around testing, design and construction of pervious concrete pavements. Dr. Nassiri’s research lab has been active in characterizing thermophysical properties of pervious concrete, modeling its thermal behavior, also testing to improve mechanical behavior of pervious concrete pavements for higher traffic volume applications, and extended durability.