Engineering behaviour of expansive clays blended with cement and GGBS

Abstract

This paper presents experimental data on the liquid limit (LL), plastic limit, plasticity index (PI), free swell index (FSI), optimum moisture content, maximum dry density (MDD), stress–strain behaviour and unconfined compressive strength (UCS) of an expansive clay blended with varying amounts of cement and ground granulated blast furnace slag (GGBS). Both cement and GGBS were independently added to the expansive clay up to 15% in increments of 5%. FSI, respectively, decreased from 145 to 100% and from 145 to 80% when cement and GGBS contents increased from 0 to 15%. LL and PI, respectively, decreased by 23 and 41% when cement content increased from 0 to 15%. Similarly, LL and PI, respectively, decreased by 14 and 30% when GGBS content increased from 0 to 15%. MDD increased, respectively, by 11 and 9·5% when cement content and GGBS content increased from 0 to 15%. The UCS of the cement–clay blends and the GGBS–clay blends increased with increasing additive contents. For a given additive content, UCS increased significantly with increasing curing period.