Utilization of Fly Ash and Waste Ceramic in Improving Characteristics of Clayey Soil: A Laboratory Study

Fly ash is a waste product obtained from coal-based thermal power stations. In the absence of proper utilization, large quantities of fly ash are dumped in the landfills. Since traces of heavy metals are present in coal, the dumping of fly ash in landfills is not ecofriendly and leads to air pollution and groundwater contamination. The ceramic tile waste is obtained from construction and tile industries which poses disposal problems and requires dumping areas causing environmental concerns. The inherent properties of these waste materials can be exploited by using in road pavement subgrade and thus solving the disposal problems. This experimental study was performed to assess the efficiency of using fly ash and waste ceramic along with poor sand for clayey soil stabilization by evaluating compaction, strength and drainage properties to be used as road sub-grade material. The addition of sand to clayey soil decreased the optimum moisture content (OMC), increased the maximum dry density (MDD) whereas the California bearing ratio (CBR) improved. Further, adding fly ash to clayey soil increased OMC value, decreased MDD value but improved the CBR value. The results indicate that adding ceramic tile waste reduced MDD value and increased OMC value and the CBR value. The drainage characteristics of composite material were better than those of clayey soil or fly ash. The stabilization of sub-grade resulted in significant savings in terms of the material required for subgrade of road pavement compared to those using un-stabilized soil. The composite containing optimum contents of clay, sand, fly ash and ceramic waste possessed better sub-grade and drainage properties and thus can be used successfully for construction of pavement subgrade of low cost roads.