High temperatures of the asphalt concrete pavements in summer contribute to the heat island phenomenon in the urban areas. The effective cool-pavement technologies are sought to mitigate the pavement environment. In t...High temperatures of the asphalt concrete pavements in summer contribute to the heat island phenomenon in the urban areas. The effective cool-pavement technologies are sought to mitigate the pavement environment. In this paper, developed heat-reflective pavements are constructed from open-graded asphalt concrete, in which voids in the upper part of the pavement are filled with a cement mortar, containing recycled materials as a fine aggregate. The recycled materials used in this study are： crushed oyster shells, roof tile debris, pottery debris, glass cullet, crushed escallops and coral sand. The temperature reduction of the pavement surfaces at an open site is measured in the summer. The results show that the maximum surface temperature of the pavements falls by approximately 8-10 ℃ compared to the asphalt concrete pavement. Furthermore, it is found that the temperature reduction is mainly due to the increased solar radiation reflectance of the pavement surface.展开更多
The outdoor ground radiation including the emitted radiation and reflected radiation plays an important role in the outdoor thermal environment. In this paper, based on the hypothesis of that the occupant body can be ...The outdoor ground radiation including the emitted radiation and reflected radiation plays an important role in the outdoor thermal environment. In this paper, based on the hypothesis of that the occupant body can be equivalent to a human cylinder and the outdoor ground surface is diffusive for radiation, a mathematical model is advanced to describe the radiation from the ground surface to the occupant. Through theoretical analysis of the mathematical model, general formulas for calculating the radiation arriving at the occupant from an annular ground surface and infinite ground surface are obtained. It shows that, the radiation from ground surface to the occupant depends on the surface temperature, reflectivity and emissivity, the arrange within the radius of 8.0m encircling the occupant can be defined as the dominant radiating area which radiates 90% radiation to the occupant. The radiative potentials of different pavement surface such grass, asphalt concrete surface, granite slab surface, terracotta bricks, colored concrete interlocking blocks are also compared with the datum measured by Tan Slew-Ann and Fwa Tien-Fang in Singapore, it shows that, in the summer sunny day, grass surface radiates more radiation in the morning but less in the afternoon than other pavement materials. Finally, discussions of reducing the radiation of outdoor ground surface are presented and main conclusions are drawn for improving the outdoor thermal environment.展开更多
文摘High temperatures of the asphalt concrete pavements in summer contribute to the heat island phenomenon in the urban areas. The effective cool-pavement technologies are sought to mitigate the pavement environment. In this paper, developed heat-reflective pavements are constructed from open-graded asphalt concrete, in which voids in the upper part of the pavement are filled with a cement mortar, containing recycled materials as a fine aggregate. The recycled materials used in this study are： crushed oyster shells, roof tile debris, pottery debris, glass cullet, crushed escallops and coral sand. The temperature reduction of the pavement surfaces at an open site is measured in the summer. The results show that the maximum surface temperature of the pavements falls by approximately 8-10 ℃ compared to the asphalt concrete pavement. Furthermore, it is found that the temperature reduction is mainly due to the increased solar radiation reflectance of the pavement surface.
基金This study was supported by the Natural Science Foundation of Fujian Province of China （Nos. Do210013, 2006J0460）.
文摘The outdoor ground radiation including the emitted radiation and reflected radiation plays an important role in the outdoor thermal environment. In this paper, based on the hypothesis of that the occupant body can be equivalent to a human cylinder and the outdoor ground surface is diffusive for radiation, a mathematical model is advanced to describe the radiation from the ground surface to the occupant. Through theoretical analysis of the mathematical model, general formulas for calculating the radiation arriving at the occupant from an annular ground surface and infinite ground surface are obtained. It shows that, the radiation from ground surface to the occupant depends on the surface temperature, reflectivity and emissivity, the arrange within the radius of 8.0m encircling the occupant can be defined as the dominant radiating area which radiates 90% radiation to the occupant. The radiative potentials of different pavement surface such grass, asphalt concrete surface, granite slab surface, terracotta bricks, colored concrete interlocking blocks are also compared with the datum measured by Tan Slew-Ann and Fwa Tien-Fang in Singapore, it shows that, in the summer sunny day, grass surface radiates more radiation in the morning but less in the afternoon than other pavement materials. Finally, discussions of reducing the radiation of outdoor ground surface are presented and main conclusions are drawn for improving the outdoor thermal environment.
