Development and Characterization of Coal-Based Thermoplastic Composite Material for Sustainable Construction

Abstract

The exploitation of coal and the disposal of waste plastic present significant environmental and economic challenges that require sustainable and profitable solutions. In response, we propose a renewable construction composite material of coal-based thermoplastic composite (CTC) that can be made from low-grade coal and plastic waste. We developed and tested the hot-press fabrication method for this CTC, using coal with a maximum particle size of 4.75 mm and recycled high-density polyethylene (HDPE). The effects of the coal fraction (50–80 wt%) on compressive properties, thermal properties, microstructure, and ecological and economic efficiencies of the CTC were investigated. Test results revealed that the compressive strength and modulus decrease as the coal fraction increases. However, the thermal properties, including thermal conductivity and specific heat, increase with higher coal contents. Compared to concrete, the CTC has about half the thermal conductivity and twice the specific heat, making it a more energy-efficient construction material. Microstructure testing helped to reveal the mechanisms behind the above behaviors of CTC from the observation of binder volume, bonding quality between coal and HDPE, and porosity variation. The life cycle analysis indicated that the CTC production reduced embodied energy, carbon footprint, and cost by up to 84%, 73%, and 14%, respectively. Therefore, we recommend the CTC with 50–70% coal fraction as an innovative construction material with satisfied mechanical and thermal properties, better cost efficiency, and a reduced ecological impact.

Eco-Friendly Sustainable Concrete and Mortar Using Coal Dust Waste

“…The use of coal dust in building materials and in particular in cement composites was considered in works [8][9][10]34]. Overall, the addition of coal dust in certain quantities can facilitate its efficient use in the production of cement and concrete and thus make a significant contribution to the sustainable development of the construction industry in terms of long-term energy savings, a reduction in greenhouse gas emissions and the mitigation of global climate change [8].…”

“…Such dust has a direct impact on the creation of a carbon footprint and the risk of not achieving sustainable development goals. As for the relevance of the scientific research of this work, it should be noted that the natural mechanism for the formation of concrete based on coal dust is complex [34]. Coal dust, as a fine powdery material, has a certain chemical composition that must be carefully taken into account when integrating such a powdered material into the composition of a concrete conglomerate.…”