A Study on Strength Behaviour of Seasonal Frozen Soils Stabilized with Cement and Wood Ash

Abstract

AbstractPavement failure in seasonal frozen areas is mainly accelerated by the periodic freezing–thawing cycles. This study investigates the suitability of cement and household waste product such as wood ash as stabilizing agent to improve the strength behaviour of soil subjected to seasonal freeze–thaw cycles. Test samples were prepared by blending the frost affected soil with 2%, 4% and 6% cement as well as 5%, 10%, 15% and 20% wood ash and combination of both, respectively. Unconfined compressive tests were performed on Soil+Cement, Soil+Wood ash and Soil+Cement+Wood ash samples after 0, 3, 7, 14 and 28 days of curing periods and 28 freeze–thaw cycles. The results show a noteworthy increase in the strength of “Soil+cement+wood ash” mix over “soil+cement” or “soil+wood ash” mix when subjected to freeze–thaw cycles and strength improvement is augmented with curing periods. The highest UCS value was found to be of soil treated with 6% cement and 20% wood ash, with an increase of UCS value from 258 kPa of untreated soil to 4405 kPa of treated soil for non-freeze–thaw cycle and 237–4572 kPa for 28 days freeze–thaw cycles. Further, scanning electron microscope and energy-dispersive X-ray spectrometer tests were conducted to comprehend the mechanism involved in the stabilization process. Change in soil structure and formation of cementitious compounds were observed on addition of cement and wood ash.KeywordsFreeze–thawWood AshUCSSEMEDX