WITHDRAWN: Effect of coal ash on strength characteristics of clayey silt soil treated with cement

Abstract

Coal-based thermal power plants produce coal ash as a by-product and the major concern is for handling and disposal of coal ash without adversely affecting the environment. There is a feasibility to utilize the coal ash in an environmentally safe manner in geotechnical engineering applications. To achieve this objective, an experimental investigation was conducted in which coal ash was used as replacement material in soil mixtures. A clayey silt soil was used in this study and class F type coal ash (CA) was blended in different proportions up to 50% by mass of the soil. The testing program comprised characterization of soil and coal ash, compaction tests and California bearing ratio (CBR) tests. The stress–strain and strength characteristics of compacted soil with coal ash and cement were analyzed. The test results showed that all the mixes achieved a higher CBR value than the control specimen. The optimum coal ash contents for clayey silt–coal ash mixes were found as 20% and 50% which showed higher CBR value, it could be due to the packing effect and imparting cohesion, respectively. The minimum cement content of 1% to the optimum mixes provided a significant improvement in CBR values of 25.19% and 29.14% as compared to the control specimen of 4.72%. These results are acceptable values and hence, the coal ash blended soil is found to be suitable for pavement subgrade and embankments constructions.