Effects of curing age and magnesium slag grinding time on mechanical properties and hydration characteristics of magnesium slag-based backfill materials

作者：Xiaobing Yang, Jian Yang, Xi Wang, Shenghua Yin, Zepeng Yan, Xizhi Zhang, Gongcheng Li, Xun Chen, Yaobin Qi, Wei Chen · 发表于：Case Studies in Construction Materials · 年份：2025 · DOI：10.1016/j.cscm.2025.e05052 · 被引用次数：4 · 研究领域：Tailings Management and Properties、Materials Engineering and Processing、Magnesium Oxide Properties and Applications

Through comprehensive analysis methods, including uniaxial compression tests, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis, the macroscopic mechanical properties and microscopic hydration mechanisms of magnesium slag-based (MS-based) backfill under different curing ages (3, 7, and 28 d) and different MS grinding time (0, 40, 60, and 80 min) were systematically investigated. The effects of these two variables on the deformation characteristics and compressive strength of MS-based backfill were examined. Additionally, the influence mechanism of MS grinding time on the micro-morphology and hydration products of MS-based backfill was elucidated. The results suggest that the stress-strain responses of MS-based backfill under different conditions exhibits typical four-stage evolution characteristics. Grinding time has a promoting effect on the strength development of MS-based backfill. When the grinding time is 80 min, the strengths of the backfill at 3, 7, and 28 d reaches 1.558, 3.110, and 10.975 MPa, respectively, meeting the strength requirements of typical mine backfill. Linear and quadratic polynomial functions effectively illustrate the relationship between both curing age as well as grinding time with respect to compressive strength in MS-based backfill. The application of grinding activation treatment proves beneficial in enhancing hydration among MS particles while significantly increasing hydrati...