Aim of the study:
The paper presents the results of testing the compressive strength, frost resistance and shear strength of stabilized fine-grained soil depending on the added hydraulic binder and the time and method of curing. Determination of these parameters was to check the suitability of the soil for stabilization purposes.

Material and methods:
The tests were performed for a coarse silt collected in Boczkowice in the Małopolskie Voivodship. The stabilizer used in the tests was Terramix F22.5, added in the amount of 3, 5 and 8% in relation to the dry matter skeleton. The test was carried out on samples immediately after stabilization, after 7 and 28 days of treatment with water and after 7 and 28 days with freezing and thawing cycles, as well as for samples without the addition of a stabilizer. The samples were formed at optimum moisture content up to obtain the compaction index close to or equal to Is = 1.00.

Results and conclusions:
On the basis of the conducted tests, it was found that the binder content used as well as the length and method of sample curing influence the improvement of geotechnical parameters. Both the compressive and shear strength of the tested soil samples depend on the method of sample care, as well as the value of the binder addition. The method of sample curing had the greatest influence on the compressive strength of the soil. Protecting the stabilized soil against water causes a significant increase in compressive strength, the enhance of compressive strength of the samples was up to 60%. The shear strength, and thus the values of the angle of internal friction and the cohesion of coarse silt, were significantly affected by content of the stabilizer. The both parameters increased with the increase of the binder addition.