Enhancing the thermal properties of cement composites through substitution of the fine aggregate using metallic material

Abstract

In this study, copper powder was substituted for up to 50% of fine aggregate in cement mortar. The effects of employing copper powder on ice-melting performance were studied. To verify the derived ice-melting results, thermal properties were analyzed. Porosity analysis, which is highly correlated with thermal properties, was investigated. Microstructure analysis included computed tomography analysis was performed. It was found that the cement mortar with 10% copper powder was the most efficient in terms of ice-melting performance and thermal properties improvement. 10% copper powder incorporation shortened the ice-melting time by about 20 minutes or more, and also improved the thermal conductivity and heat flux by 3 and 2 times more, respectively. The porosity test and computed tomography analysis have demonstrated that copper powder can produce an agglomeration effect if the amount is higher than 10% in the cement mortar system. The porosity of the 10% copper powder incorporation was decreased by about 5% compared with plain mortar, while that of the 30% and 50% copper powder incorporation was increased by about 2.5% and 8%, respectively. In addition, 10% copper powder incorporation had the highest compressive strength and flexural strength. As a result, 10% copper powder substitution was an optimal choice.