Chicken Feather Ash (CFA) as a Partial Replacement of Cement in Concrete

Abstract

Every day, large quantities of chicken feathers are disposed of as waste at markets where birds are slaughtered and sold for meat. The possibility of using Chicken feather ash (CFA) as a partial replacement of cement in the concrete making was investigated. Water-cement ratio and percentage CFA used for replacement were chosen as variables in the design of the experiment. Compressive strength and workability were chosen as the required responses to observe and analyzed using response surface methodology. Full factorial design was used for the design of experiment, with CFA replacement and water-cement ratio ranging from 2 – 11% and 0.3 – 0.7 % by mass respectively. There were 27 trial mixes and the freshly made concrete mix was tested for workability. Concrete cubes were molded and cured for 7 and 14 days and were crushed to determine the compressive strength. It was found that as the CFA percentage increases, the workability of the concrete increases making it more fluid. The optimum water-cement ratio was observed to range from 0.49 to 0.51 % as the curing age increases. The optimum compressive strength was observed to range from 15.6 to 18.6 N/mm2 as the curing age increased. However, the allowable range of CFA to be used for concrete making is 3.8 to 6.34 % beyond which compressive strength reduces.