Experimental Study on Modification of Expanded Soil by Glutinous Rice Mortar Material

Abstract

There are facilities such as highways and houses in the distribution area of expansive soils in Yanji region, while there are large agricultural fields in the surrounding area. In order to ensure that the nature of expansive soil will not have an impact on engineering facilities, and does not hinder the cultivation of farmland. In this paper, the expansion and contraction characteristics, mechanical properties, physical properties and microstructure of Yanji expansive soil were tested using glutinous rice mortar as the improvement material, and the difference between glutinous rice mortar improvement and traditional lime improvement was compared with the two methods of conventional maintenance and CO2 maintenance. The test results showed that: 1) Compared with the plain soil samples, the internal friction angle of the modified glutinous rice mortar samples increased by 98%~166%, the cohesion of the soil samples increased by 81%~310%, and the free swelling rate was reduced to 30%~45% of that of the plain soil samples. 2) Compared with the lime-amended specimens, the internal friction angle of the glutinous rice mortar-amended specimens decreased by 18 ~ 29%, the cohesive strength increased by 21 ~ 37.8%, and there was no significant difference in the free swell and shrinkage rates. 3) The free expansion rate of the specimens under CO2 conditioning was reduced to 21% ~ 48%, the unconfined compressive strength was increased by 122% ~ 258% compared with that of the plain soil, the pH was decreased by 1.7 ~ 2.4, and the peak strength was reached at 7 days of conditioning. The lime-modified soil under. 4) CO2 conditioning generates calcium carbonate crystals between the layers of montmorillonite minerals, and agglomerated cubic and spherical calcium carbonate crystals in the pores of the modified soil with glutinous rice mortar. The results of the above tests indicate that glutinous rice ash slurry can be used as a good modifier to improve expansive soils; CO2-maintained lime-amended soils and ash slurry-amended soils are an ideal ecological management mechanism.