This guide provides information on how to use low-density concrete for civil works projects. It focuses on the differences between low-density and normal-density concrete in terms of materials, processing, mixing, placing, and other construction-related aspects. The goal is to help users select and use materials effectively for making low-density concrete. The guide emphasizes the use of low-density concrete in hydraulic structures. Key topics covered include material selection, mixture proportioning, job controls, and quality verification. The guide also highlights the importance of coordination between design and field activities, preparation for construction, and concrete testing.