Performance of resource saving agro-industrial wastes and their utilization in lightweight concrete -A review

Abstract

The high demand for natural aggregates has created opportunities for the use of agro-industrial waste in the building sector brought on by rising urbanization and the disposal issue of agricultural and industrial waste. Numerous agricultural waste and industrial by-products are already employed in concrete in place of cement, fine aggregate, coarse aggregate and reinforcing elements. Furthermore, there is an increase in the use of Lightweight concrete (LWC) in civil structures such as high-rise buildings, off-shore structures, and long-span bridges owing to the need of concrete, lighter than the conventional one. Presence of natural aggregates makes the concrete dense and heavy, hence the use of lightweight aggregates (LWA), such as perlite, paper industry waste, expanded shale, volcanic pumice, slate, wood ash waste, and expanded polystyrene (EPS), in the production of LWC can effectively decrease the self-weight of a structure. In a comparable manner agricultural wastes, like oil palm shell (OPS), coconut shell (CS), rice husk ash (RHA) and industrial waste like fly ash, plastic aggregate, silica fume (SF), metakaolin (MK) have the potential of a LWA. This study reviewed the utilization of oil palm shells (OPS), coconut shells (CS), expanded polystyrene (EPS), and silica fume (SF) in concrete, among the numerous available agro-industrial wastes. For the past decade, research has been ongoing on aggregate processing to meet special concrete requirements such as low density, thermal insulation, and strength. These wastes exhibit similar properties to conventional concrete when used in combination with mineral additives like SF and RHA, among others. The study also highlights the eco-efficiency and functional benefits of using these wastes as lightweight aggregates (LWA).