Utilization of Fly Ash and Coconut Shell as Sustainable Alternatives in M30 Grade Concrete: A Feasibility Study

The gradual reduction in availability of traditional construction materials and disposal of waste materials are the two most important challenges which engineers or researchers face. To encounter these challenges, industrial or agricultural waste as a substitute for traditional building materials is generally adopted. Among various waste generated in our country, fly ash and coconut shell waste occupy a significant proportion and, if not appropriately managed, can cause serious waste disposal problems. Therefore, in this investigation, a feasibility study on the valorisation of fly ash and coconut shell as substitute materials to cement and natural coarse aggregates (NA), respectively in M30 grade concrete is carried out. The study incorporates the examination of two variables, namely the fly ash (FA) content ranging from 0% to 30% and the coconut shell aggregates (CSA) content ranging from 0% to 30%. The present study assesses the fresh and hardened characteristics of concrete mixtures using different proportions of fly ash as a substitute for cement and coconut shell aggregates as a replacement for coarse aggregate. Based on the obtained data, it is evident that when NA is replaced by CSA in all instances, the hardened properties of the concrete reduced gradually, while the use of FA as a partial substitute to cement by up to 20% showed positive results and could almost counter act the loss in strength of the concrete with incorporation of 20% CSA.