Stabilization treatment of Na-montmorillonite with binary mixtures of lime and steelmaking slag

Abstract

This paper reports the influence of lime-slag mixtures and curing on stabilization of Na-montmorillonite clays that have greater water holding capacity than other soils studied previously. For this purpose, different amounts of hydrated lime and two types of steelmaking slag including Granulated Blast Furnace Slag (GBFS) and Basic Oxygen Furnace Slag (BOFS) were added in a ratio of 1:1 to the soil and finally the investigation was carried out at 25 °C. The efficiency of soil-additive mixtures was measured using different laboratory tests such as plasticity index, pH, electrical conductivity, swelling potential and unconfined compressive strength. The results showed that blends containing 5% additive, particularly in LG (Lime:GBFS = 1:1), significantly reduced swelling potential of highly expansive soil at one day curing. Furthermore, addition of 20% LB (Lime:BOFS = 1:1) to the samples after 1 and 90 days of treatment increased their compressive strength by 8 and 13 times, respectively.

Keywords:

• Lime
• Na-montmorillonite
• granulated blast furnace slag
• basic oxygen furnace slag
• swelling
• unconfined compressive strength

Acknowledgement

The authors wish to acknowledge the financial support was provided by the deputy of Research of Islamic Azad University, Hamedan Branch.