Compressive Strength Properties Evaluation of Concrete Containing Iron-Laden Spent Sand from Water Treatment Systems and River Sand

Abstract

Spent sand from water treatment plants has long been a source of environmental concerns due to mineral pollution, notably iron, and environmental degradation. Hence, its use for road pavement construction would be a better option, therefore, the objective of this paper was to investigate the Compressive Strength Properties of Concrete Containing Iron-laden spent sand from Water Treatment Systems and untreated River sand using appropriate standard techniques with concrete cubes of 1:2:4 ratios of sand, cement, and granite. The results showed that after curing for 7 to 28 days, River sand gradually increased in compressive strength, reaching a maximum of 18.9N/mm² on day 28, whereas, Spent sand deceased in strength over time, peaking at 12.6N/mm² on day 14 and declining to 11.8N/mm² by day 28. The River sand consistently outperformed spent sand in both rebound number and compressive strength tests throughout all curing days (7, 14, and 28 days). A pattern was also noticed in the compressive strength of spent sand, which increased from the 7^th to the 14^th days of curing but decreased by the 28^th day for all samples. This revealed that, while spent sand has potential as a construction material, its structural integrity does not compare to that of untreated river sand and should only be used in milder constructions. The researcher also recommended more research on these materials.