Synergistic Effects of Corn Stalk Ash and Fly Ash on the Properties of Lightweight Concrete Using Pumice Aggregate

The research investigates the characteristics of lightweight concrete by incorporating class C fly ash (FA) and corn stalk ash (CSA) as partial substitutes for cement, along with lightweight pumice aggregates replacing coarse aggregates. The massive energy consumption in the cement manufacturing process is posing a threat to the environment. Furthermore, using waste to dispose of and re-cover natural concrete components might harm the environment. This investigation includes the study of workability, water absorption, compressive strength, and unit weight test. In this experimental study, 0%, 5%, 10%, and 20% by weight of cement have been replaced with FA and CSA, and coarse aggregates are replaced in different proportions, including 0%, 5%, 10% and 20% by pumice aggregate. In total, 15 mix proportions were prepared and used for compressive strength, water absorption and other parameter each. Based on the results obtained, the optimal solution for optimum strength (54.5 MPa) is obtained by replacing 5% cement with FA and CSA each and coarse aggregate with pumice aggregate. Furthermore, workability increases with increased fly ash and corn stalk ash content. Water absorption also decreases with an increase in corn stalk ash as well as in fly ash. XRD patterns with significant peaks demonstrate that most fly ash and corn stalk ash structures are amorphous. XRF is employed to determine the elemental composition of FA and CSA.