Using Spray Technique of Bentonite Slurry in Treatment of Sand Dunes.

Sand dunes in the Arabian Peninsula cause many problems for the population, environment and desert roads, which directly affects the regional development. Many studies have been carried out to solve this problem. However, they used agricultural and chemical materials to stabilize sand dunes which gave a limited success. This study used the non- active calcium bentonite ore from Khulais region, Saudi Arabia. The stabilization process by this proposed method is not only on the surface of sand dunes, but also to some depths from surface. That is to provide a relative thick bed on the sand dune surface, which has the ability to resist wind blew and be not able to be removed. In addition, it becomes able to conserve water for very long time. The present research deals with the comparison between surface and subsurface spraying of bentonite slurry in sand treatment. The method using subsurface spraying gives some improvement in the engineering properties of sand dunes. Their values increased to (1.5-4.0), twice the original values compared with only (1.0-2.50) twice of the original values in case of using surface spraying. These values have been obtained after 10 days of treatment and using only 2% of bentonite. [ABSTRACT FROM AUTHOR]