A study on pedestrian pavement thermal performance with reference to associated materials

Abstract

The urban environment is continuously expanding and the majority of the green spaces in urban areas are replaced by various grey infrastructure such as buildings, roads, and pavements. Improper planning of infrastructure exacerbates negative impacts on urban microclimates that leads to an increase in average annual air temperatures by 1°C to 3°C, demonstrating an effect known as Urban Heat Island (UHI). Approximately one-third of the urban land uses are known to be covered with paved surfaces. Therefore, the contribution of pavements to UHI is of a serious concern. The energy performance of grey infrastructure is largely influenced by the materials associated, and the material's street physical properties. Identification of the thermal performance variations of pavers of alternative materials will assist landscape planners to select suitable paver types in an optimal way to reduce UHI, after considering the surrounding structures and the direction of shading. The current study was concentrated on three pavement types representing changes in materials; 1) Cement Pavers (CP), 2) Terracotta Pavers (TP) and 3) Grass Pavers (GP), to assess the thermal performance of pavement designs which are commonly used for urban pavement construction. The study was conducted in an urban environment in Colombo, Sri Lanka by considering three replicates for each material. One-way ANOVA was performed to analyze the significant differences on the thermal performance of different material types. According to the results obtained, both TP and GP showed significant difference to the thermal performance of CP from 9.00 AM to 3.00 PM. Furthermore, between 8.00 AM–3.00 PM there was no significance difference among the performance between GP and TP. However, TP showed the lowest surface temperature levels and heat emittance considering heat levels throughout the day. The maximum temperature difference compared to CP was shown at 1.00 PM as 4.49°C with TP and as 4.42°C with GP. The findings of this study provide valuable insights in integrating commonly used materials in pavement designing for urban areas, in order to regulate microclimates and reduce the impacts of UHI.