Influence of biomass ash and coconut shell in scrap steel fiber reinforced concrete

To develop a sustainable concrete solution, the aggregates and cement in the concrete mixture were partially replaced with Cocos nucifera endocarp (coconut shell) aggregate and biomass ash (sugarcane bagasse ash) respectively. The fresh and hardened properties were studied for three types of mixes (i) the concrete mix with 10-30% replacement of cement with bagasse ash (BA), (ii) Bagasse ash concrete mix with scrap steel fiber and (ii) Bagasse ash concrete with scrap fiber and 10 - 50% coconut shell aggregate. The fresh property of concrete is positively influenced by the addition of bagasse ash. With the addition of scrap fibers and coconut shell the workability reduces by 47% when compared to the control mix. The slump values recorded for all the mixes were within the permissible limit. The density of concrete decreases with the inclusion of bagasse ash and coconut shell which helps reduce the dead weight of structural elements. The mechanical property of concrete increased by 5%, 6% and 8% in compression, split and flexure modes respectively, for 10% bagasse ash steel fiber reinforced concrete. Replacement of gravel with coconut shell affects the strength properties, but all the values were within the permissible limit for structural concrete application. The SEM image analysis showed that the porosity increased with coconut shell content. From the fresh and hardened concrete test results, it was observed that the coconut shell, bagasse ash and scrap fiber can be effectively used as substitutes for concrete ingredients to develop a sustainable fiber reinforced concrete solution.