In the heart of Hanoi, Vietnam, researchers are turning industrial waste into a promising construction material, offering a sustainable alternative to traditional concrete. Chuc Ngoc Pham, a scientist at the Institute of Material Science under the Vietnam Academy of Science and Technology, has been leading a team exploring the potential of geopolymers made from fly ash, blast furnace slag, and incinerator slags. Their findings, published in the journal *Materials Research Express* (translated as “Materials Research Express”), could significantly impact the energy and construction sectors, promoting a circular economy and reducing environmental pollution.
Geopolymers are inorganic polymers that can be created using aluminosilicate materials, often derived from industrial by-products. Pham and his team investigated the mechanical and physical properties of geopolymers made from a mix of these industrial wastes, with and without nano-silica additives. Their goal was to optimize the mix design to achieve high compressive strength and durability, while also ensuring that the materials do not leach harmful heavy metals.
The team found that the optimal mix for geopolymers incorporating incinerator and blast furnace slags had a NaOH concentration of 14M, with mass ratios of incinerator/blast furnace slag to water glass/NaOH of 4:6 and 7:3, respectively. “These ratios and concentrations were crucial in achieving the desired mechanical properties,” Pham explained. The resulting geopolymer demonstrated environmentally acceptable levels of heavy metal leaching, addressing a significant concern for using industrial waste in construction materials.
For geopolymers based on fly ash and blast furnace slags, the team discovered that a 60/40 ratio yielded the highest compressive strength of 57.4 MPa. Adding 1.5% nano-silica to this mix further increased the compressive strength by up to 11.5%. This enhanced geopolymer concrete achieved waterproofing grades from W10 to W14 and could protect steel reinforcement against corrosion in water environments containing chloride and sulfate ions.
The implications of this research are substantial for the energy and construction sectors. By utilizing industrial waste, geopolymer concrete reduces the consumption of natural resources and energy, contributing to a more sustainable built environment. “This technology not only helps in managing industrial waste but also offers a high-performance alternative to traditional concrete,” Pham noted.
The potential commercial impacts are equally promising. As the demand for sustainable construction materials grows, geopolymer concrete made from industrial waste could become a valuable commodity. The energy sector, in particular, stands to benefit from this innovation, as it aligns with the increasing focus on circular economy principles and reducing carbon footprints.
Looking ahead, this research could shape future developments in the field by encouraging further exploration of geopolymer technologies. As Pham and his team continue to refine their methods, the construction industry may see a shift towards more widespread adoption of geopolymer concrete, driven by its environmental benefits and superior performance characteristics.
In the quest for sustainable construction materials, Pham’s work offers a beacon of hope. By transforming industrial waste into high-performance geopolymer concrete, his research paves the way for a greener future, where the energy and construction sectors can thrive in harmony with the environment.