Back Filling Compound, also known as backfill material or simply backfill, refers to a material that is used to fill the space between a buried pipeline or underground structure and the surrounding soil. The purpose of backfilling is to provide support and stability to the structure, protect it from external forces, and prevent water from infiltrating and damaging the structure. Back Filling Compound is typically made of natural or synthetic materials such as sand, crushed rock, or concrete.