Engineering and Microstructure Properties of Soft Clay Improved with Ordinary Portland Cement and Polymers

This study investigated properties of soft Bangkok clay stabilized with ordinary Portland cement (OPC) and various polymers. Variables included initial water content (۱.۰LL, ۱.۵LL, and ۲.۰LL; LL = liquid limit), polymer type (polyvinyl alcohol (PVA), polyethylene glycol (PEG), and polyvinylpyrrolidone (PVP), polymer concentration (۱%, ۳%, ۵% and ۷%), and curing time. The unconfined compressive strength (UCS), consolidation, permeability, and microstructure were analyzed. UCS decreased with increasing water content due to delayed polymer bonding; however, at ۱.۰LL, polymers effectively bonded clay particles, resulting in higher UCS. A ۳% polymer concentration yielded the highest UCS, while ۵–۷% led to non-homogeneous structures and reduced UCS. The UCS of the sample with PEG outperformed those with PVA and PVP. At ۱.۰LL and ۳% polymer, ۲۸-day UCS values were ۱.۲۰ MPa (PEG), ۱.۱۲ MPa (PVA), and ۱.۰۴ MPa (PVP), all exceeding the Department of Highways’ standard ۱.۰ MPa. Higher polymer concentrations decreased void ratios and permeability by forming hydrogel layers and thin films, increasing soil density. SEM/EDS analysis confirmed ۳% polymers formed uniform films enhancing soil bonding, while ۷% resulted in thicker, irregular films, reducing UCS. These findings suggest that polymers could be a promising alternative to OPC in environmentally friendly deep mixing applications. Doi: ۱۰.۲۸۹۹۱/CEJ-۲۰۲۵-۰۱۱-۰۴-۰۲۲ Full Text: PDF

کلیدواژه ها:

Unconfined Compressive Strength ، Consolidation ، Polyvinyl Alcohol ، Polyethylene Glycol ، Polyvinylpyrrolidone.