Freeze-thaw performance of a cement-treated expansive soil

Abstract

This experimental study presents an attempt on the effect of cement addition to expansive soil on its deformation and strength behaviours when subjected to freezing–thawing (F–T) action. A series of laboratory tests on cemented-treated expansive clay samples after 28–d curing periods were conducted. The experimental program involved freezing–thawing test, volume measurement, and unconfined compression test. The effects were evaluated by focusing on the water loss, volume change, stress-strain response, unconfined compression strength, resilient modulus and strain at failure after a sequence of freeze–thaw cycles. Eight groups of expansive soil samples were prepared with four different cement contents (i.e. 0%, 3%, 5% and 7% by weight of soil) and subjected to 0, 1, 2, 3, 5, 7, 9, and 12 F–T cycles, respectively. The analysis of experimental results indicated that: 1) Cement additive makes expansive soil become less sensitive to moisture and cement–induced hydration reaction will reduce swelling–shrinkage characteristics triggered by F–T cycles; 2) The inclusion of cement within expansive soil causes an increase in unconfined compressive strength, resilient modulus, but a decrease in strain at failure. However, such effect induced by cement will be diluted by F–T cycles; 3) Cement can retard the degradation of resilient modulus but increase a faster strength reduction against F–T weathering. 4) Upon F–T cycles, un–cemented expansive soil will become more brittle, while cement-treated soils more ductile before 1st F-T cycle. A power function, independent of F–T cycles and cement contents, exists between the strain at failure and UCS. The results obtained from the study are fairly promising to employ cement additive against freeze–thaw resistance of expansive soils.