New block design and laying parameters for interlocking concrete block pavements to improve human thermal comfort levels in urban spaces

Abstract

Asphalt, concrete and interlocking concrete block paving (ICBP) are the most commonly used paving materials. Artificial pavements are one of the key factors for the urban heat island effect. Due to high irradiance, the ambient air temperature rises above human thermal comfort levels. Studies have shown that ambient air temperatures above asphalt and concrete surfaces are significantly higher than those above ICBP pavements. Typically, paving blocks are used in public spaces that are generally used by pedestrians. During the daytime, the surface temperature of pavements rises and walking on pavements becomes very uncomfortable. The thermal behaviour of interlocking concrete block pavements is mainly governed by solar irradiation. When pavements are exposed to solar radiation, paving blocks are heated and the temperature of their top surfaces rises. Several factors such as heat capacity, convection film coefficient, and heat conductivity directly affect the temperature of ICBP. In this study, a finite element model (FEM) is developed to model the thermal behaviour of ICBP and the model is validated using experimental data. The verified model is used to predict the thermal behaviour for different paving arrangements. A parametric analysis of the ICBP parameters shows a significant reduction of block temperature by (1) increasing the gaps, (2) leaving air in the gaps, (3) using blocks with vertical holes and (4) using smaller blocks.

Keywords:

• ICBP
• interlocking concrete block pavements
• human thermal comfort
• finite element modelling
• surface temperature
• ambient air temperature

Acknowledgments

The material in this paper is based on work supported by Department of Civil Engineering, University of Moratuwa, Sri Lanka.