Enhancing the thermal conductivity of hot-mix asphalt

Abstract

Conductive hot-mix asphalt is recommended for enhancing the solar energy collection performance of an asphalt solar collector. This type of collector consists of embedded tubes with circulating water or air inside pavement construction to generate power. This work intends to shed light on the selection of novel components for the preparation of conductive asphalt mixes. Lee's disc method was used to determine the thermal conductivity of this composite material. A comprehensive examination was conducted to prepare reference and conductive asphalt discs by manufacturing asphalt mixtures in a laboratory specified for this work. New Iraqian natural resource materials, including quartzite sandstones and silica sands, and Iraqian industrial waste materials, such as slag stones, steel wool fibres and metallic waste powder, were employed as conductive components. The results showed that the conductive materials increase the thermal conductivity of the reference asphalt mixture up to 42.75% and 66.65% for quartzite and slag combinations, respectively. Slag aggregates should not be utilized as conductive material in asphalt mixes without increasing the binder ratio. Proportions of 4% and 38% of steel wool fibres and metallic waste powder additives, respectively, were found to produce the optimal results for thermal conductivity enhancement. The air void contents and fracturing ratio of conductive discs were decreased when using conductive novel components, which is an indication of the importance of current findings in improving asphalt mixtures in heat storage and transfer applications.