Development of porous composite matrix using fly ash, waste tyre rubber, and rice husk ash for sustainable engineering applications

Abstract

Utilization of fly ash (FA), waste tyre rubber (WTR), and rice husk ash (RHA) has grown as research towards handling the disposal issue and its environmental degradation concerns. The present research and development has delineated a sustainable porous composite matrix utilizing industrial and agricultural wastes with minimal content of cement and water. The research study has included three phases of development such as FA-Cement; FA-WTR-Cement; and FA-WTR-RHA Cement. Two optimized matrices FA-WTR-RHA-Cement (50%+20%+10%+20% and 50%+15%+15%+20%) by weight have exhibited density of 1.4 g/cm³, compressive strength of 8.0 and 8.8 N/mm2, and system porosity of 61% and 60.5% respectively. FESEM and EDX have further validated a stable internal microstructure characterized by well-integrated waste particles, thereby improving the functionality of the matrix. A leachability study has also been carried out on the optimized matrices, with results well below the regulatory levels. Overall, the developed composite has offered a low-carbon, eco friendly alternative to traditional materials, without any chemicals/additives, pre- and post-treatment of the waste, for sustainable civil and environmental engineering applications.