Investigation of stabilized weak sub-grade soils mechanical performance under the freeze-thaw effect

In this study, it is focused on improving the mechanical properties of fine-grained silty soils by stabilizing them with lime and cement additives. For this purpose, the silty soil sample taken from the Kuzköy location of Çeltikçi district of Burdur was used. First, index properties were determined and soil classification was made. Then the physical properties of the soil sample were determined and mechanical performance tests were applied. The cylindrical soil samples prepared by mixing with lime + Portland cement at optimum water content were cured for 1, 7, 14 and 28 days in a minimum 95% humidity, and then freeze-thaw cycles were applied for 3 and 5 cycles. To determine the mechanical performance of samples after freeze-thaw cycles; California bearing ratio test, unconfined compression test and dynamic triaxial test were performed. According to the results, it was observed that the unconfined compressive strengths decreased as the number of F-T cycles increased in unconfined compression tests. As a result of 3 F-T cycles, the strength decreased by 25% on average, and as a result of 5 F-T cycles, by an average of 48%. As a result of the triaxial compression test, the Resilient Modulus (Mr) values of the samples obtained on average 5.6% lower than the samples without F-T cycle. As a result, it has been determined that cement+lime additives can be used effectively in the stabilization of silty sub-grade soils in Çeltikçi district of Burdur. It has been observed that the stabilization obtained by using cement + lime in fine-grained silty soils significantly increases the strength value of the soil samples. It has been determined that additionally applied F-T cycles have a significant negative effect on the strength of the stabilized soil samples. In this study, the importance of stabilizing silty sub-grade soils with the addition of lime + cement additives is emphasized, especially in cold climates where there are collapse problems on highways.