Shear Properties of Clinker Ash and Construction Generated Soil Mixtures

Clinker ash in coal fly ash is known as a geomaterial superior to natural sand because of its light weight, high shear strength, and excellent permeability. However, the clinker ash content in coal fly ash is as low as 10%, and efficient utilization methods are needed. In this study, clinker ash is mixed with construction generated soil to expand its effective use, and physical tests, compaction tests, and triaxial compression tests are conducted to clarify its shear properties. The triaxial compression tests were conducted under both drained and undrained conditions. Construction generated soil, which is classified as organic clay, was used as the mixed soil. Since the construction generated soil did not contain soil particles larger than 19 mm in diameter, it was used in condition of original grain size distribution for a series of tests. The soil mixtures were made with dry mass ratios of 0:10, 3:7, 5:5, 7:3, and 10:0. The relationship between deviator stress and axial strain under undrained conditions shows that deviator stress moves upward as the clinker ash mixing ratio increases. The pore water pressure coefficient Af decreased as the clinker ash mixing ratio increased. This result depends on the dilatancy characteristics of clinker ash and construction generated soil mixtures. The maximum deviator stress also increased with increasing clinker ash mixing ratio, and the tendency of the increase depended on the drainage conditions even in the same clinker ash mixing ratio.