Performance comparison of two low-carbon binders for stabilization of soft sensitive Malminkenttä clay

Malminkenttä, in the northern part of city of Helsinki, will be a new residential area. The surface area is about 2.4 km2. The soil conditions of the area are mainly soft sensitive clay that requires intensive ground improvement actions for the development of the residential project. Dry deep mixing (DDM) has been planned as one of the key ground improvement methods. The preliminary preconstruction plan made in 2017 showed that if lime-cement were used as binder material for DDM in Malminkenttä the CO2 emissions would be vast. Therefore, low-carbon binders have been studied widely to reduce emissions. This paper presents performance comparison of laboratory test results for different binders. The aim is to show that low-carbon binders are a real solution for DDM and that they can perform even better than traditional lime-cement. The laboratory tests include characterization, uniaxial compression and triaxial tests. Another aim is to analyze the differences of shear strength, yield stresses and deformation moduli determined by uniaxial compression and triaxial test.