Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Collapsibility


Improving Collapsibility and Compressibility of Gypseous Sandy Soil Using Bentonite and Kaolinite

Hussein H. Karim; T. Schanz; Maha H. Nasif

Engineering and Technology Journal, 2012, Volume 30, Issue 18, Pages 3141-3153

The sandy soil which covers the surface layer for the investigated area consists of
high gypsum content (50%). The soil was found to be a “collapsible” soil. Thus
bentonite and kaolinite have been used as an improving agents for such soil. The
essential idea of this study represents an investigation of the possibility of using
these materials as additives with different percents (5%, 10%, 15%, and 20%) to
enhance these soils. A testing program was conducted on 9 models of untreated and
treated gypseous soil specimens to study the behavior of such mixes as well as their
effects on physical properties, collapsibility and compressibility characteristics. It
was concluded that a significant reduction in collapsibility reaching 80 to 82 % for
the 10 percent mixed kaolinite and bentonite respectively. Lowest compression
index (Cc) and recompression index (Cr) have been obtained using the same
percentages of mixed additives. Generally, best improving results have been
obtained using bentonite additive (specially the ratio 10%) for its finer grains than
those of kaolinite.