Recycling sand-wash fines as synthetic lightweight aggregates

Local aggregate sources in Kuwait are scarce and quarrying for coarse aggregates has been completely stopped. The construction industry is now entirely dependent on imported aggregates. Research has been carried out at the Kuwait Institute for Scientific Research to explore suitable indigenous raw materials as alternative sources for the production of synthetic lightweight aggregates (LWAs). This paper presents the outcome of the investigation on LWAs made using sand-wash fines from a sand-washing plant in Kuwait, in addition to other waste materials acting as gas generating and fuelling agents such as used lube oil and municipal sewage sludge. The physical and mechanical properties of the sand-wash fines and other ingredients, and synthetic LWA products were assessed. The investigation revealed that the sand-wash fines contain all the necessary elements to enable the bloating and sintering processes. The engineering properties of concrete made with the LWAs were also tested.