Research
| Title： | Reuse of soil-like material solidified by a biomass fly ash-based binder as engineering backfill material and its performance evaluation |
|---|---|
| First author： | Qin, Zhifa; Jin, Jiaxu; Liu, Lei; Zhang, Yi; Du, Yuelin; Yang, Yong; Zuo, Shenghao |
| Journal： | JOURNAL OF CLEANER PRODUCTION |
| Years： | 2023 |
| DOI： | 10.1016/j.jclepro.2023.136824 |
| Abstract： | The reuse of soil-like material (SLM) obtained from landfill mining as engineering backfill materials contributes to sustainable waste management. In this paper, a new biomass fly ash-based binder (BB) containing biomass fly ash (BFA), carbide slag (CS), and phosphogypsum (PG) is designed to solidify the SLMs. The mechanical prop-erties, permeability, microstructure, and physicochemical characteristics of the BB-solidified SLM are compre-hensively characterized. The optimum proportion of ternary BBs consisting of 80% BFA, 15% CS, and 5% PG was determined through tests on paste samples. The different landfill depths of SLMs show significant variability in solidification/stabilization (S/S) effects due to their different physicochemical properties. The mechanical and permeability properties of BB-solidified SLM improve with the increasing BB content and the age of solidifica-tion. Microstructural and phase analyses indicated the formation of significant amounts of ettringite crystals and C-(A)-S-H gels were generated by the pozzolanic reaction, forming a stable and dense microstructure. The var-iations in pH and conductivity were correlated with the development of mechanical properties. Moreover, the organic matter content and leached heavy metal content of SLM2 and SLM3 after S/S treatment did not exceed the specified limits. This study can provide theoretical guidance for the resource utilization of the stabilized/ solidified SLMs. |
