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

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.