Study on Freeze-thaw Performance of Improved Subgrade Filler with Large Steel Slag Content

Abstract In order to evaluate the use effect of the modified subgrade filler with large amount of steel slag in the seasonal freezing area, the properties of the filler under the freeze-thaw cycle were studied. On the basis of the optimum mix ratio of improved soil determined by previous geotechnical tests, the variation trend and influence law of various performance parameters of improved soil under different stress and temperature conditions and after multiple freeze-thaw cycles were analyzed through freeze-thaw cycle and temperature control triaxial test. The results show that the failure stress, internal friction angle, shear strength and dynamic elastic modulus of the modified soil with large amount of steel slag decrease significantly after the first freeze-thaw cycle, reaching 7.89%, 6.41%, 13.57%, 30.16%, and then the decreasing amplitude decreases and gradually becomes stable.