Performance of Concrete Containing Water-Hyacinth Ash (Wha) as a Cement Replacement: Fresh and Mechanical Properties

Considerable efforts are exerted worldwide to use local and waste materials to avoid stockpiling and conserving the environment. The current research investigates the possibility of using the ash produced from the water-hyacinth plant, which causes enormous environmental problems, as a partial cement replacement. The study revealed that under certain burning and grinding conditions, the water-hyacinth ash (WHA) has amorphous and pozzolanic characteristics. The research presents the fresh and mechanical performances of the WHA in paste, mortar, and concrete mixtures. The experimental evaluation included two WHA burning conditions (in the open air for 60 min and closed oven at 600oC for 30 min), different cement replacement ratios (5%, 10%, 15%) by WHA, and the use of three coarse aggregate types. The results illustrate that the WHA is a pozzolanic material that contributes to strength gain over time. The concrete containing WHA showed better performance than the control made with only Portland cement and comparable behavior to mixtures containing 10% silica fume. Based on the current study, the 10% WHA replacement ratio to cement can be considered optimum. The two WHA types obtained from the two different burning methods yielded a slight difference in performance, and the choice should be optimized based on environmental conservation.