The usability of bottom ash as an engineering material when amended with different matrices

This study aims at investigating the utilization of bottom ash obtained from four different power stations as a construction fill and landfill bottom liner. For the matrix material, commercial powdered bentonite, construction lime and natural clay were used. Compaction tests (Standard Proctor and vibratory hammer) were carried out on the different ratios of bottom ash and matrix material. The optimum water content ranged from 40 to 45% yielding a dry density mostly ca 1 Mg m^?3. Uniaxial compressive strength of mixtures ranges from 0.1 to 0.5 kgf cm^?2 which showed a 3–20-fold increase when tested on 28-day cured specimens. Triaxial compression tests yield varying rates of shear strength which also showed as high as an 11-fold increase for cured specimens. The hydraulic conductivity of those mixtures was mostly ca 10^?4 cm s^?1, which is not considered to be low enough for landfill lining. Leaching tests using deionized water were also performed to investigate the possible effect of leachate produced from the mixtures on the environment. In conclusion a light density and environmentally friendly mixture is determined and proposed as construction filler.