Investigation of color pigment incorporated roller compacted high performance concrete as a mitigation tool against urban heat island

Abstract

Traditional asphalt pavement is one of the causes of urban heat island due to its low albedo. Although the use of various pavement materials is widely preferred method to mitigate urban heat island effect, the use of color pigment added roller compacted high performance concrete as road pavement is a new approach. Within the scope of this research color pigment incorporated roller compacted high performance concrete (CIP-RCHPC) was produced to mitigate urban heat island. Color pigment was used at the rate of 0.25 % 0.5 % 0.75 % and 1 % of cement by weight. Vebe, compressive strength, splitting tensile strength and albedo determination tests were performed on the samples. Highest albedo was obtained as 0.69 on the RCHPC sample that containing color pigment 0.75 % of cement by weight. A selected area was modeled in ENVI-met software with two configurations. In the base configuration road pavement material was set to be asphalt and in roller compacted concrete (RCC) configuration pavement material was set to be RCHPC with 0.69 albedo value. Air temperature, relative humidity, surface temperature and reflected sort wave radiation results were obtained from the both simulations. In the asphalt configuration the highest air temperature was determined to be 33.72 °C while it was determined to be 32.55 °C RCC configuration. Utilization of color incorporated RCHPC as a pavement material results in 1.63 °C decrease on air temperature, 9.69 °C reduce on surface temperature, 8 % increase on relative humidity and 56 % on sort wave reflectance, in the model area which is an ordinary urban area containing residential buildings and streets where speed limit is 50 km/h.