Mechanical characterization of Pb contaminated loess solidified/stabilized by red mud, ground granulated blast furnace slag and waste tire textile fibers.

The presence of contaminated soil and the storage of industrial solid waste materials are two major thorny issues that pose a serious threat to the environment. In this context, the resourceful use of industrial solid wastes to remediate contaminated soil offers a sustainable way to address both problems. In this research, waste tire textile fiber (WTTF), red mud (RM) and ground granulated blast furnace slag (GGBS) were used to solidify Pb contaminated loess. Based on the 28-day and 90-day unconfined compressive strengths of the samples, the ratios of the ternary curing materials were optimized using the response surface method, and the significant effects of one-factor and two-factor were analyzed. The 28-day compressive strength exceeded 0.35 MPa when the dosages of RM, GGBS, and WTTF were 2.5, 7.5, and 0.6%, respectively. In addition, a comprehensive microanalysis of the cured 28-day samples was conducted, and the effects of C-S-H, C-A-S-H gels and WTTF on the strength increase were corroborated. The Pb contaminated loess solidified by the method of this study can be used as the backfill for the solid waste landfill or subgrade, which opens up a new way to improve the utilization rate of industrial solid waste.