Soil stabilization known as the process of improving the engineering properties of soils is a method applied when the engineering properties of soil are not suitable for purpose. There are several methods of soil stabilization that could be implemented to improve the physical characteristics of the soil. In this study, the pine tree sawdust as an organic material wase used as additive material for stabilization of clayey soils and the influence of pine tree sawdust on the geotechnical properties of clayey soil was investigated in terms of strength behaviors. The pine tree sawdust is an organic waste resulting from the mechanical milling or processing of timber (wood) into various standard shapes and useable sizes. The strength properties of the clayey soil when blended with pine tree sawdust indicates that the pine tree sawdust is a good stabilization material for this problematic soil. As a result, it is concluded that the pine tree sawdust material as an organic material can be successfully used for the reinforce of clayey soils in the geotechnical applications.

Expansive soils are very important natural geological materials used in the geotechnical applications in the worldwide. After compacting, they are used as hydraulic barriers in earth structures, such as core of earth fill dams, landfill liners, and etc. However, these soils have some defects from technical points of view. To remove the defects, one of the soil improvement methods is mixing of these soils with granular materials. In this study, pine tree sawdust was used as granular additive material to stabilize the expansive soils. The effects of pine saw dust on the volume compressibility of expansive soils were investigated by using experimental studies under laboratory conditions. The test results showed that the pine saw dust positively affected the geotechnical properties in term of volume compressibility manner. As a consequently, the geotechnical properties of the expansive soil when blended with pine tree sawdust indicates that the pine tree sawdust is a good modification material for this problematic soil.

This paper evaluates the use of waste material mixtures including marble dust and scrap tire rubber the stabilization of fine-grained soils in order to remove the effects of freeze-thaw cycles. In this study, a fine-grained soil material was stabilized by using waste material mixtures. Natural and stabilized fine-grained soil samples were subjected to freeze-thaw cycles under different curing periods. After the freeze-thaw cycles, compressive strength tests were performed to investigate effects of waste material mixtures on the freeze-thaw resistance of fine-grained soil samples. The experimental results showed that the samples of fine-grained soil stabilized with waste material mixtures have high freeze-thaw durability as compared to unstabilized fine-grained soil samples. Consequently, we conclude that waste material mixtures including marble dust and scrap tire rubber, can be successfully used as an additive material to enhance the freeze-thaw durability of fine-grained soils for soil stabilization in the geotechnical applications.