This document presents the results of a study on the durability of concrete with partial replacement of fine aggregate with hypo sludge. Tests were conducted on conventional concrete and concrete with 20% fine aggregate replaced by hypo sludge. The durability tests included acid attack, sulphate attack, rapid chloride penetration, and sorptivity. The results showed that the 20% replacement concrete had slightly higher weight and strength loss than conventional concrete for acid and sulphate attack. For rapid chloride penetration and sorptivity, the 20% replacement concrete performed similar to or slightly better than conventional concrete. In general, the study found that concrete with 20% fine aggregate replaced by hypo sludge exhibited comparable or improved durability compared to conventional concrete.