Geological and physiochemical characterisation of construction sands in Qatar

This paper investigates the two different types of naturally occurring construction sands in Qatar (fluvial and aeolian dune). These sands are mined from natural deposits that consist of various layers formed at different geological times. After mining, sand treatment plants further process the various layers to be sold commercially for concrete and mortar applications. The booming construction industry in Qatar is only allowed to utilise the locally mined sands which are limited in quantity and are in high demand. Properties of these sands were hardly ever systematically published. This study aims at an initial characterisation and comparison of these sands, augmented by linking sand characteristics to geological processes.Representative fluvial and aeolian sand samples were collected from natural deposits in the south of Qatar and compared to the standard European Norm sand. A rigorous testing program was carried out, comprising of geological, physical, chemical and microstructure investigations. Results were bench marked against the prevalent Qatar Construction Standards specified properties and showed compliance with the thresholds apart from sulphate contents for fluvial sand.In conclusion, Qatar sands consist of high percentages of carbonates and traces of clay minerals and their properties strongly vary with geological layers. In contrast, European Norm sand purely consists of quartz. Thus, selective mining is recommended as a means to upgrade the quality of sand in Qatar. Hence, it is recommended to extract fluvial sand from Channel and Sand Bar geological layers while avoiding mining from abandonment paleosol layers. For aeolian dune sand, selective mining from top layers of deposits while avoiding base layers close to the sulphate and carbonate rich Sabkha is suggested.