Impact of various binders on loess durability subjected to different freeze-thaw regimes.

Freezing and thawing (F/T) is an important occurrence in cold regions influencing soil geotechnical characteristics. Current study investigates effects of lime, Rice Husk Ash (RHA) and Nano-clay on unconfined compressive strength and F/T of loess under open and closed schemes. Loess was treated with 2, 4, 6 and 8% lime and RHA and 0.5, 1.0, 1.5 and 2% Nano-clay and compacted at optimum conditions. Samples were cured for 1, 7, 14 and 28 days at 35 °C before freezing at −23 °C and thawing at room temperature for 24 h intervals. Tests conducted on untreated and RHA and Nano-clay treated samples showed total loss of strength after one F/T cycle with noticeable weight and volume changes by samples subjected to open F/T. Exposing samples to closed F/T resulted in smaller changes in volume and strength. Samples treated independently with lime or concurrently with RHA and Nano-clay showed significant resistance to F/T particularly with curing time. Formations of chemical compounds bind particles, reduce void ratio resulting in a solid durable structure resisting freezing. Open F/T proved more detrimental than closed F/T scheme exhibiting moisture accessibility to be a dominant factor on F/T process. [ABSTRACT FROM AUTHOR]