2025/01/01 by Yi-Lun Chen, Zhong Xu, Ge Chen +4 · 1 voice
Engineering · Materials Science · #Concrete and Cement Materials Research #Geomechanics and Mining Engineering #Magnesium Oxide Properties and Applications
paper · doi:10.1515/ntrev-2025-0225
openalex publication_date 2025/01/01 · openalex created_date 2025/10/15 · openalex updated_date 2026/07/22
Abstract To enhance the engineering applicability of coal gangue-based geopolymer concrete (CGGC), nano-silica (NS) was used to modify CGGC, the influence of different NS dosage (0–2.5 wt%) on mechanical properties and durability of CGGC was studied. The compressive, flexural, and splitting tensile strengths were tested, the mass and strength loss of samples were analyzed under different sulfate attack ages with different NS dosages. With the increase in the dosage of NS, the mechanical strength and sulfate resistance of CGGC first increase and then decrease. When the dosage is 1%, the mechanical properties are improved most significantly, and when the dosage is 1.5%, the sulfate resistance is the strongest. Combined with scanning electron microscopy, X-ray diffraction, and pore image analysis tests, it was revealed that NS optimized the pore defects in the matrix, generated more cementitious materials, and made the microstructure of the matrix more uniform and denser, both porosity and total pore number had a good linear correlation with compressive strength and sulfate resistance. The smaller the porosity and the fewer the total pore number, the better the engineering applicability of the sample.