Performance analysis of thermally and non-conductive cement mortar prepared from waste iron scraps and magnetite sand

ABSTRACT

The existing thermal conductive pavement exploits heating cables as the heat source commonly. However, the poor thermal conductivity of the upper layer in the pavement structure results in a low energy utilisation efficiency. In order to ensure energy transfer efficiency and reduce energy consumption, this paper investigates the application of waste iron scraps and magnetite sand in cement-based materials. The mechanical properties, electrical conductivity and thermal conductivity of cement mortar were tested by ISO method, two-electrode method and plate steady-state method, and the drying shrinkage condition of the specimens was studied by drying shrinkage test. The results showed that there was a critical value of mechanical property enhancement of mortar by waste iron scraps and magnetite sand, while the electrical and thermal conductivity were positively correlated with their admixtures. The study obtained the optimal ratio of waste iron scraps and magnetite sand in the system that would exhibit excellent thermal and mechanical properties while having low electrical conductivity. It can be concluded that this study provides suggestions for solving the problems of low exploitation rate of solid waste and low heat transfer efficiency of thermal conductive pavement.

KEYWORDS:

• Solid waste recycling utilisation
• mechanical property
• thermal conductivity
• electrical conductivity
• Gray correlation

Disclosure statement

The authors declare that they have no known competing interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

All data used during the research appear in the submitted article.

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities, Chang'an University [grant number 300102310301]; Ningbo Science and Technology Innovation 2025 Major Project [grant number 2019B10048]; the Fundamental Research Funds for the Central Universities, Chang'an University [grant numbers 300102311404 and 300102313501]; Open Funding of x’an Key Laboratory of Modern Transportation Function Materials, Chang’ an University [grant number 300102313505].