CONSOLIDATION BEHAVIOR OF SOIL STABILIZED WITH CEMENT: EXPERIMENTAL ANALYSIS OF ROHRI CANAL’S SOIL (PAKISTAN)

Abstract

This research aims to study the consolidation characteristics of clayey soil samples taken from the Rohri Canal in Pakistan, using Ordinary Portland Cement (OPC) as a stabilizer. This study, however, deviates from the general trend of literature that, over the years, has shown a significant decrease in compressibility of soils over time, by revealing a peculiar short-term effect of cement addition, which initially results in an increase in vertical strain and compressibility parameters of soils. The results of the incremental loading Oedometer test on soil samples containing 5% and 10% cement content, after short curing periods, revealed that the 10% cement content-24h sample recorded the highest vertical strain of 27.4%, coefficient of volumetric compressibility (mᵥ = 0.128 m²/MN), and compression index (C꜀ = 0.239), almost tripling the value of the untreated soil samples, which recorded a value of 0.087 for the compression index. This unusual increase in compressibility is due to the formation of a porous soil-cement skeleton, which collapses under high vertical stress levels, up to 640 kPa.

Comparative analysis of sources (2015-2026) indicates that, although the process of long-term curing for 28 to 90 days results in densification of the microstructure through the formation of Calcium Silicate Hydrate, short-term stabilization can increase settlement risks. These results are critical for the design and construction of hydraulic fillings in Pakistan, as immediate mechanical response is the main concern.