Development of Practical Approaches to Quantify Pavement Thermophysical Properties: An Energy-Conserving Engineering Demonstration

Current issues such as global warming and energy conservation are being discussed more than ever worldwide. Today’s pavement sustainability evaluation methods recognize the complicated nature of pavement thermophysical characteristics but do not address albedo-related indicators or outcomes. Pavement infrastructure sustainability assessment systems that objectively prescribe certain thermophysical qualities and albedo criteria relating to “cool pavement,” “urban heat island,” and other cleaner production effects targets are required. The aim of this study was to quantitatively analyze the thermophysical properties and albedo of urban roads to validate the thermal models used in AASHTOWare Pavement ME (PaveME) version 2.3 Design software. Core samples of both portland cement concrete pavement (PCC) and asphalt pavement (AC) were drilled at 10 locations in a number of sites. In the central and eastern United States, seven field sample locations in different cities were chosen to represent a diversity of local aggregate types, pavement varieties and years of age, and environments. New test methods were then developed and used to quantify the thermal properties of pavements, including thermal conductivity (k), specific heat capacity (SH), emissivity, and albedo. The pavement thermal properties from the literature were summarized and compared to the experimental data. The pavement thermal performance varies greatly in different regions. Thermal conductivity values of PCC and AC cores from northern PCC and AC pavement samples were lower than those found in southern samples. Further endeavors are needed to enhance the accuracy of measuring thermal conductivity value and heat capacity value by utilizing pavement samples. Doing so would enable state highway agencies to document the thermal properties of their pavements and determine the appropriate thermal input values to reduce the negative impact of pavement sustainability and achieve cleaner production goals for pavement infrastructure.