Investigation of the Effect of Pavement Albedo on Urban Temperature Using Computational Fluid Dynamics Simulation

This paper investigated the effect of the changed albedo of colored pavement on the urban temperature. The surface albedo of different conventional and colored pavement slabs was measured in the laboratory. Numerical simulations were conducted to determine the relationship between pavement albedo and the temperatures of pavement and its surrounding environment in the local urban. Results showed that colored porous portland cement concrete (PPCC) slabs have higher albedo values than conventional gray PPCC and black asphalt concrete, but conventional dense portland cement concrete (DPCC) has the highest albedo value owing to its smooth surface. The temperature of colored PPCC (except black PPCC) slabs at 1-cm depth was about 1 degrees C-6 degrees C lower than that of conventional gray PPCC due to the high albedo, and the green PPCC slab had the best cooling effect among all PPCCs. The simulated temperature profiles of the PPCC slab were found to be in good agreement with the laboratory test results. The local urban simulation showed that the colored pavement has a noticeable effect on reducing pavement surface temperature and nearby air temperature. Compared with open-graded friction course, which had an albedo value of 0.058, conventional gray DPCC with an albedo value of 0.32 had a temperature at 0.2 m below the pavement surface that was 0.83 degrees C lower at 3:00 p.m. of a typical summer day.