Strength assessment of chemically stabilised soft soils

Abstract

Since the development of the modern concept of chemical stabilisation of soils, geotechnical engineers have attempted to develop methodologies to describe the strength development based on a rational criterion, as in concrete technology, in which the binder content, the water content and/or the void ratio play an essential role. This paper presents a methodology to assess the unconfined compressive strength (UCS) in cement-based stabilised soft soils with a high water content (w > wL). A number of UCS tests were performed on cement-based stabilised Coimbra soft soil and the results obtained showed that the binder content and the liquidity index are fundamental parameters in assessment of the target strength. A simple and expedite method based on normalisation by the liquidity index is proposed. This method was successfully validated for a wide range of chemically stabilised soft soils, subjected to zero or small curing stresses, thus demonstrating its versatility. Applying the generalised relationship of the method, data from only one test condition are required to assess the UCS for other possible combinations of binder content and liquidity index.