Mechanical evaluation of CFBFA-GGBS geopolymer grouting material for subgrade remediation: Compatibility, interfacial bonding, and performance optimization

分类： 矿山工程技术 >> 矿山地质学 提交时间： 2025-07-17

Hualei Wang Chenchen Li Junhui Zhang Jianwei Xie Fan Gu

摘要： Road trenchless grouting is widely used for subgrade remediation due to its convenient application, low-carbon, and low-disturbance features. This study focuses on the circulating fluidized bed fly ash (CFBFA) - ground granulated blast furnace slag (GGBS) grouting material, researching its preparation and remediation effect of subgrade distress via laboratory tests. Results show that as CFBFA content rises, the grouting material's fluidity increases, bleeding rate decreases, setting time prolongs, and compressive and flexural strengths decrease. Through a self-designed test, the subgrade soil type, distress type, grouting pressure, and material compatibility are explored. The grouting material significantly affects the remediation of subgrade voids and slurry-soil interfaces. For example, at a 10 mm loose thickness and 1.5 MPa grouting pressure, the optimal remediation effect can reach 2.66 times of the strength of 96% compacted sandy clay of low liquid limit (CLS) subgrade soil, with a 59.10% increase in shear strength. Clayey sand (SC) has better loose remediation and interface shear strength than CLS subgrade soil. Based on data analysis, suitable grouting materials and pressures are recommended for different soil and distress types. Further X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) tests are conducted. XRD pattern shows a weak geopolymerization reaction between grouting material and subgrade soil, with SC having stronger reactivity. SEM and EDS results demonstrate that the grouting material effectively binds subgrade soil particles and fills voids, with the combined effect of soil particle participation in the reaction and cementation significantly enhancing the bonding efficiency. This study classifies the grouting remediation effect into filling, slurry-soil reaction, cation exchange, and bonding effect, systematically explores the compatibility of subgrade factors with grouting materials and pressures, and provides new methods and ideas for improving the remediation effect.

同行评议状态:待评议

 点击量 4  下载量 2  评论 0