Abstract

A laboratory study was conducted to enhance the engineering properties of soil with sewage sludge ash (SSA) that can be used in different engineering applications. Proctor compaction test was conducted to determine the optimum moisture content and maximum dry density of soil samples with arbitrarily selected SSA contents. Atterberg limits and grain size distribution tests were conducted to classify the soil. An unconfined compressive strength test was conducted with air-dry for a few arbitrarily selected curing periods to determine the strength. It was concluded from this study that the addition of SSA enhanced the soil type as well as the engineering properties. The optimum soil to SSA mixture was a mixture of soil with 7.5% SSA for a curing period of 28 days, which is expected to perform better as engineering materials. A mixture of soil with 5% SSA content for the same curing period could also be used as a viable alternative. The addition of SSA with soil decreased the plasticity index that indicated a more pronounced reduction in volumetric swelling. The study revealed that potentially 7.5% of SSA can be used as a part of soil property improvement that would go to landfills to be managed otherwise.

Keywords

Sewage sludge ash, Soil engineering properties, Beneficial use of SSA, Sand-size particles