Experimental Studies on Bottom Ash and Expanded Polystyrene Beads–Based Geomaterial

Bottom ash is a by-product produced from burning of pulverized coal in thermal power plants. The increasing production of bottom ash and its disposal in an eco-friendly manner is a matter of concern. This paper concisely describes the suitability of bottom ash to be used in civil engineering applications as a way to minimize the amount of its disposal in the environment and in the direction of sustainable development. The proposed geomaterial was prepared by blending bottom ash with expanded polystyrene (EPS) beads and a binder such as cement. The experiments were conducted by adding EPS beads with different mix proportions. The mix ratio percentages 0.3, 0.6, 0.9, 1.2, and 1.5 were used in the study. The cement to bottom ash (C/BA) ratios of 10 and 20% were used in the study. All the ratios used in the study are with respect to weight of bottom ash. The compressive strength of geomaterial was evaluated for curing periods of 7, 14, and 28 days. The effects of various mix ratios, cement content, and curing periods on the density, compressive strength, and initial tangent modulus was studied and the results were incorporated. Test result indicated that the density of geomaterial reduced from 650 to $360\mathrm{kg}/{\mathrm{m}}^3$ with addition of EPS beads from 0.3 to 1.5%. For a particular curing period, compressive strength reduced marginally following the inclusion of EPS beads in geomaterial. For each mix ratio, compressive strength increased with increasing curing periods. The initial tangent modulus of the geomaterial decreased with increasing mix ratio values. The prepared geomaterial was light in weight comparitively and it can be used as a substitute to conventional fill materials.