River sand is obtained by dredging from river beds. It has the major characteristics that since it has been subjected to years of abrasion, its particle shape is more or less rounded and smooth, and since it has been subjected to years of washing, it has very low silt and clay contents.
With lower silt and clay contents, river sand improves the quality control of the concrete/mortar production because the presence of too much silt and/or clay would adversely affect the workability and strength of the concrete/mortar produced. Coarse river sand is recommended for reinforcement cement concrete (RCC) and brick / blockwork.
