In the heart of Bangkok, a team of researchers led by Warayut Dokduea at King Mongkut’s University of Technology Thonburi is turning industrial waste into a valuable resource, potentially revolutionizing the construction and energy sectors. Their groundbreaking study, published in the journal *Case Studies in Construction Materials* (translated as “Studies on Building Materials”), explores the use of industrial by-products as sustainable alternatives to traditional construction materials.
The research focuses on controlled low-strength materials (CLSM), a versatile construction material used for various applications, including backfilling and void filling. Dokduea and his team investigated the potential of using ground coal bottom ash (GBA) mixed with ground calcium carbide residue (GCR) as a primary binder, and sieved coal bottom ash (SBA) as a replacement for river sand. The results could have significant implications for the energy sector, particularly in coal-fired power plants, which produce large quantities of coal bottom ash as a by-product.
“Our study demonstrates that industrial by-products can be effectively utilized as binders and fine aggregates for one-part lightweight CLSM,” said Dokduea. “This approach not only promotes waste valorization but also conserves natural resources, contributing to a more sustainable construction industry.”
The team’s experiments revealed that the proportions of GBA and GCR significantly influenced the fresh and hardened properties of the CLSM. They found that an optimal dosage of sodium metasilicate pentahydrate (SM), a solid activator, resulted in a 28-day unconfined compressive strength (UCS) of 2.54 MPa, meeting typical CLSM requirements. This finding is particularly noteworthy, as it suggests that industrial by-products can be used to create a material with comparable strength to traditional CLSM.
Moreover, the study’s microstructural analysis using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) revealed that the GCR acted as a crucial source of calcium oxide. This finding could pave the way for further research into the use of industrial by-products in construction materials.
The commercial impacts of this research are substantial. By utilizing industrial by-products as binders and fine aggregates, construction companies can reduce their reliance on traditional materials, lowering costs and minimizing environmental impact. Furthermore, the energy sector could benefit from this research by finding new uses for coal bottom ash, a by-product that is often disposed of in landfills.
As the world grapples with the challenges of climate change and resource depletion, this research offers a glimmer of hope. By turning waste into a valuable resource, Dokduea and his team are not only advancing the field of construction materials but also contributing to a more sustainable future.
“This study is a testament to the power of innovation and the potential of industrial by-products,” said Dokduea. “We hope that our findings will inspire further research and encourage the construction and energy sectors to embrace a more sustainable approach.”
As the construction industry continues to evolve, the utilization of industrial by-products as binders and fine aggregates for CLSM could become a standard practice. This shift could not only reduce the environmental impact of construction but also create new opportunities for the energy sector to repurpose its waste. The future of construction materials is here, and it’s made from waste.