Study The Effect of Coal Bottom Ash And Limestone Dust as Partial Replacement of Sand and Cement

Abstract

With the tremendous increase in the population, per capita consumption of cement production has increased by many folds. This has lead to an exponential increase in the carbon dioxide levels causing extreme pollution to the environment. Necessary steps have been taken by the researchers worldwide to find alternatives to cement so as save the environment from this rising pollution. In this paper coal bottom ash [CBA] which is a by product of coal burning thermal power plant is used as partial replacement of sand and Waste limestone dust [WLSD] as partial replacement of cement in concrete. These two are the waste materials and their utilisation in concrete proves economical as the cost of concrete will be less and dumping cost of these two materials is a problem of discussion therefore, the replacements are done at 0%, (10%, 5%), (20% ,5%), (30% ,5%), (40%, 5%),(60%, 5%), (80%, 5%) of sand and cement respectively at fixed water cement [W/C] ratio (0.45) and fixed slump ranges with mix (1:1.2:2.5). The result showed that at fixed W/C ratio the strength (compressive strength, flexural strength, split tensile strength) and durability increased initially at small percentages of (10%, 5%), (20% ,5%), (30% ,5%) and later when the percentage of replacement is increased as (40%, 5%),(60%, 5%), and (80%, 5%) the strength and durability decreased.

Coalash as Sustainable Material for Low Energy Building

“…Water-cement ratio was same for all mixes. Increase in strength was found consistent up to 30% sand substitution and 5% cement substitution [26]. Ghosh et al had experimented with coal bottom ash and fly ash separately as sand substitute in different concrete mix proportions.…”

“…OPC, sand, bottom ash and stone aggregate as the concrete mix constituents were used. The results revealed that 10-30% replacement of sand by bottom ash did not adversely impact the desired strength gain in the concrete, barring some losses in workability and flexural strength parameters [13][14][15][16][17][18][19]. Another group of Researchers investigated about the suitability of fly ash and bottom ash as replacement material of cement and normal river sand utilized in concrete making.…”

Reuse of fly ash and bottom ash in mortars with improved thermal conductivity performance for buildings

“…However the gradation of particles in bottom ash and sand showed some similarity, and overall, bottom ash is recommended favourably as a replacement material to sand. Abbas et al. (2016) had studied the effect of partial replacement of cement and sand by limestone dust and bottom ash respectively.…”