Abstract
The modification of soil has become a major drive in construction and geoenvironmental engineering in recent years. Researches towards the effective incorporation of wastes as cement blenders and enhancers with environmental friendly impacts are increasing. This paper channeled the utilization of commercially available industrial waste- Fly ash (FA) in South Africa towards the modification and improvement of kaolinitic clay sampled from a disposal site. One-dimensional consolidation tests were conducted to investigate the effect of integrating varied proportions of FA on the compressibility behavioral patterns of a parent compressible landfill material. Compacted specimens were modified at optimum water content (OWC) and maximum dry unit weight (MDUW) by the incorporation of an industrial waste material to the parent soil. The generated specimens were subjected to incremental vertical loadings/pressures in a fixed ring odometer. This was done to simulate the impact of waste loads from a typical landfill on the consolidation characteristics of the modified specimens in a view for use as bottom liners in domestic waste containment facilities. The addition of different proportions of FA waste to the kaolinitic parent clay resulted in considerable improvements in compaction characteristics. Thus, the results of this study revealed that the incorporated industrial waste effectively increased one-dimensional stiffness and as such, successfully decreased settlement. Under adequate strength and operative conditions, the modified kaolinitic clay soil can withstand loadings from waste heaps and after recommended scrutiny by experts, may be initiated into landfill designs as an eco-friendly cost reducing agent.