Soft Clay Treatment Using Portland Cement and Hydrated Lime

Abstract

Soft soils often cause difficulties in construction operations with their low strength, low strength, and high compressibility. However, the engineering properties of these soils can be enhanced by soil stabilization. This research is carried out to study the effects of using hydrated lime and Portland cement for stabilization of soft clay soil collected from the cleaning of Mowais canal bed in Zagazig, Egypt. Two types of experimental testing are performed on the natural and stabilized soils. Unconfined compression strength tests are conducted on treated and untreated soft clay samples. In addition, model footing tests are also conducted on the untreated and treated soft soils. Unconfined compression test results showed that mixing hydrated lime and Portland cement with soft clay soils are effective in increasing the treated soft soil strength and reducing its compressibility. Soils treated with high dosage of cement (from 7% to 10%) showed lower effectiveness of lime. However, for low dosage cement (4%), the lime effectiveness is significant. Curing time has a noticeable impact on the strength of the cement-treated samples and cement-lime mixture treated samples. Model tank tests are performed to study the effect of treated soft clay with 4% cement + 4% lime on the settlement of (10*10 cm) square model footing. Results showed that the measured settlements in treated soils are remarkably lower than the untreated ones especially when increasing the depth and extension of treated zone under footing.