Volume 53

Investigating the Thermal Performance of Novel Permeable Concrete Pavements through Numerical Modelling Hafiz Muhammad Adeel Hassan, Mohammad Taher Ghalandari, Alalea Kia

Abstract

A novel high strength clogging resistant permeable pavement (CRP, also known as Kiacrete) has been developed to prevent surface flooding by absorbing stormwater runoff. Ground source energy systems (GSES) are a sustainable method to melt ice/snow on pavements. Heat energy is deposited into the ground during the summer and extracted in the winter. In this study, a numerical model has been developed, using COMSOL Multiphysics, to investigate the thermal performance of Kiacrete that is heated with a GSES. The numerical results were validated against that of the experimental values. The experimental setup consisted of i) a Kiacrete slab (290 mm × 290 mm × 80 mm) with 144 equidistant pores (each pore was 6 mm in diameter); ii) a heating water bath that pumped 40°C hot water into a standard High-Density Polyethylene (HDPE) pipe of 24 mm in diameter at a flow rate of 18.5 litres/minute. This pipe was placed underneath Kiacrete, at its centre, to mimic the ground source energy; iii) an aggregate layer (Thames Valley River gravel ≥5 mm) to simulate the ground conditions; and iv) a cooling water bath that pumped 10°C cold water into an aluminium plate with embedded copper pipes of 8.12 mm inner diameter, spaced 18 mm apart. This cooling plate was placed underneath the aggregate layer to mimic the ground temperature conditions within the UK. K-type thermocouples were placed at different heights and locations within the Kiacrete pores and the surrounding concrete. A good agreement was observed between the numerical simulation results and the experimental values. The heat propagation inside the concrete, in lateral direction, was found to be symmetrical. Furthermore, the pores inside Kiacrete produced the effect of small chimneys supporting the convection heat transfer, with conduction heat transfer occurring inside the surrounding solid concrete. This study provides the basis for investigating the heat transfer characteristics of a new type of permeable concrete pavement, whilst providing useful insights into developing complex numerical models for simulating its efficiency in melting ice and snow.

Keywords Numerical modelling, thermal performance, permeable pavement