Influence of pavement materials on the thermal environment of outdoor spaces

Abstract

About 80% of the population of Singapore live in public housing estates built by the Housing and Development Board of Singapore. A typical neighbourhood in a public housing estate consists of several multi-storey buildings (from 8 to 25 storeys) laid out in a quadrangle enclosing an open space for outdoor play-grounds, car parks and private access roads into the neighbourhood. As car parks and access roads form the bulk of open spaces in these estates, it is likely that the outdoor thermal environment is much influenced by the materials used in their pavement construction. This is of special concern to the housing authority and community organizations since most community activities occur in the open spaces at ground level on weekends, and after working hours (5 pm) on weekdays. The present study does not attempt to quantify the effects of paving materials on air temperature, or on some comfort index for people inhabiting the outdoor space. However, this paper describes the experiments and analysis used to evaluate the comparative performance of several different pavement types with respect to their surface temperature behaviour and heat output to the environment as a result of daily exposure to solar irradiation in the Singapore climatic condition. It is found that pavement materials such as granite slab, terracotta bricks and coloured concrete interlocking blocks give lower surface temperatures and lower heat output to the environment than the conventional asphaltic concrete pavements used presently. A definite improvement to the thermal environment can be expected when any of these alternative pavement materials are used for the car parks and access roads in the housing estates of Singapore. © 1992.