Quality Assessment of River Sand from Different Sources Used in Construction Purposes in Duhok Governorate at Kurdistan – Iraq

Abstract

Concrete is the most widely used construction material in the world. Some previous studies claim that substandard and low-quality concrete materials account for the majority of building collapse causes. These have mainly been attributed to the poor quality of concrete ingredients. Data regarding the clay and silt content in the river sand sources, and their impact on concrete’s compressive strength that is used in construction in Duhok and its surroundings were missing. Aggregates usually affect freshly mixed proportions and properties. This research aimed to investigate the quality of sand & its impact on the concrete’s compressive strength. Natural river sand assessment was carried out, which is used as fine aggregate in concrete production, in this case, in Duhok city and its surroundings. Five sand sources (Kalaka Yasen Axa, Khazir, Gomly, Khabur, and Dijla) were chosen for the study. Each source sample was subjected to sieve analysis, fineness modulus (FM), silt and clay content, specific gravity, and compressive strength of concrete made with these sand types. It was deduced that Duhok and its surroundings’ sand from Kalaka Yasen Axa and Khazir is composed of clay and silt content exceeding the allowable Iraqi specifications (IQS) and British Standard (B.S) limits. This has caused a significant drop in concrete strength. It was found that the concrete mixtures suffer from strength reduction as a result of the gradation and impurities of the sand used. Also, the sand samples with fineness modulus values outside the standards range are more likely to cause concrete workability issues.

Keywords

• concrete
• fine aggregate
• river sand
• sand quality
• compressive strength
• construction