This doctoral thesis deals with the stabilization of fine-grained soils using by-product originated hydraulic binders. The use of fine-grained soils as subsoil for infrastructure projects is often limited because of the risk for instability. Another reason why building on these soils is not desired is insuÿcient serviceability of the final structure caused by settlements or frost heave that occur in fine-grained soils. Therefore, these soils are often excavated, transported and landfilled. By means of stabilization with hydraulic binder, fine-grained soils can be improved and thereby utilized on site. In case by-products can be used as binders, the method of stabilization combines di˙erent sustainability aspects (reduced carbon footprint of the binder, reduced need of excavation, transport and landfilling as well as quarrying). The method of deep stabilization is often used in Sweden to increase the bearing capacity and to reduce settlements. In countries with more moderate climate than Sweden, stabilization is regularly used also to reduce the frost susceptibility of fine-grained soils in the frost active part of the subsoil.However, the influence of the combination of low curing temperature and freezing and thawing on stabilized soils is unclear, which leads to reduced applicability of this method of stabilization in regions with longer seasonal frost and low annual mean temperature. This thesis focuses on how curing at low temperatures (mean temperature +4› to+7› ) combined with freezing and thawing cycles influences the stabilizing reaction of by-product originated hydraulic binders in fine-grained soil.Three di˙erent combinations of inorganic fine-grained soils with by-product originated hydraulic binders were investigated in laboratory studies. The testing program included curing at +4› for 14, 28 and 90 days, twelve freezing and thawing cycles as well as 28 days of additional curing time after the last thawing. The results of the three laboratory studies were analyzed statistically regarding the varied influence factors (binder content, days of curing before and after freezing and thawing).In a field study, stabilized uncompacted fine-grained sulfide soil was used as cover mate-rial on a landfill. By-products from paper and cement industry were used as hydraulic binders. Samples were taken from the stabilized sulfidic fine-grained soil one year after the installation. Mainly geotechnical aspects as particle size distribution (PSD) and un-confined compressive strength (UCS) were investigated. In addition, the bu˙ering e˙ect of the binder was tested by pH measurements. Moreover, the mineral composition was investigated by X-ray di˙raction (XRD) and the micro-structure of some samples was investigated by Scanning Electron Microscopy (SEM). Parallel to the field study, samples were taken from the stabilized material directly after the installation of the field test. These samples were cured for one year in the laboratory under conditions comparable to those in the field. The testing program for these samples was similar to that for the field study.The main findings of this research can be summarized as follows:If fine-grained soil is mixed with the chosen by-products and compacted, the strength will increase compared to unstabilized soil even in cold environment and frost. The strength increase is slower in cold environment compared to reference values from literature for higher temperature.The chosen by-products bu˙er the potential acidification of the sulfide soil in cold en-vironment and frost. At the same time strength increase of stabilized sulfide soil in cold environment and frost can be achieved if compacted and protected against water percolation.