Potential Use of Rice Husk Ash (RHA) in Flowable Fill Concrete

Flowable fill is a self-compacting material, which has been developed in recent years. It is a relatively new construction technology where rapid construction is needed for different applications such as backfilling walls, sewer trenches, bridge abutments, conduit trenches, pile excavations, and retaining walls. The objective of this study is to evaluate the usage of RHA in producing low strength and self-consolidating flowable fill concrete (FFC). Two different RHA samples (600 µm and 150 µm) in three different percentages (40%, 60%, and 80% by the weight) of Ordinary Portland Cement (OPC) have been used to prepare flowable fill mixture. The evaluation processes of these fresh FFC mixtures includes determination of strength, setting time, flowability, unit weight, and air content in the laboratory. Further, two field demonstration projects have been planned to evaluate their workability, placement, and in-service performance. Findings of this study will help the transportation and the construction agencies in finding a cost-effective construction material