Investigations on Carbonation of Lime Stabilized Expansive Soil from Micro-Level Perspectives

TLDR: In this article , the effects of carbonation on the compressive strength of lime-stabilized compacted expansive soil by varying the dosage of lime content and curing period were investigated using a thermogravimetric analyzer, Fourier transform infrared spectrometer, and mercury intrusion porosimeter.

Abstract: Carbonation is a chemical reaction that occurs invariably throughout the service life of lime-stabilized soil. Carbonation results in densification owing to the precipitation of reaction product calcite within the pore structure. However, the pore structure of lime-stabilized soil varies during curing due to the progressive surface modifications and pozzolanic reactions. Given this, the present study investigates the effects of carbonation on the compressive strength of lime stabilized compacted expansive soil by varying the dosage of lime content and curing period. The chemical, molecular, and microstructure changes upon carbonation were assessed using a thermogravimetric analyzer, Fourier transform infrared spectrometer, and mercury intrusion porosimeter. Results showed that the porosity of lime stabilized soil increased with initial lime content and curing period. Also, the permeation of gas and consequent changes in the mechanical performance upon carbonation is observed to be highly dependent on the availability of macropores and residual lime in a stabilized expansive soil.