In the quest for sustainable construction materials, a team of researchers led by Zhenbo Wang from the China University of Mining and Technology (Beijing) has made a significant breakthrough. Their study, published in *Case Studies in Construction Materials* (translated from Chinese as “典型案例：建筑材料”), explores the synergic effects of steel slag and coal gangue powder on cementitious grouting materials, offering a promising solution for the energy sector and beyond.
The research focuses on enhancing the performance of cement grouting materials while promoting the utilization of solid waste. By replacing a portion of Ordinary Portland Cement (OPC) with high volumes of steel slag and coal gangue powder, and further modifying the mix with sulphate aluminate cement (SAC), the team has developed eco-friendly grouting materials with improved properties.
“The rapid hydration of SAC shortens the setting time of the slurry and reduces the bleeding rate,” explains Wang. This is crucial for applications in the energy sector, where quick setting and minimal bleeding can enhance efficiency and reduce costs. The hydration of steel slag micro powder forms a gel network that intertwines with SAC hydration products, significantly improving compressive strength. However, the study found that excessive replacement of OPC with steel slag can prolong the setting time, while coal gangue powder, although it accelerates setting, impairs strength development due to its inert phases and weak interfaces.
The optimal performance was achieved when the solid waste replacement ratio was set at 0.5, with a steel slag-coal gangue powder ratio of 0.75:0.25. This balance ensures shorter setting time, lower bleeding rate, and higher 28-day compressive strength, making it an ideal candidate for concealed engineering applications in the energy sector.
The implications of this research are far-reaching. By providing a novel technical pathway for developing sustainable grouting materials, it offers practical guidance for mix design in various engineering applications. The study not only achieves high solid waste incorporation but also reveals the intricate relationship between raw material dosages and slurry performance.
As the energy sector continues to seek sustainable and cost-effective solutions, this research paves the way for future developments in the field of cementitious materials. By leveraging the synergic effects of steel slag and coal gangue powder, engineers and researchers can create more efficient and environmentally friendly construction materials, ultimately contributing to a greener and more sustainable future.