Influence addition of Fine Sawdust on the Physical Properties of Expansive Soil in the Middle Nile Delta, Egypt

This study evaluated how the fresh fine sawdust from Pinewood affects some hydro-physical properties of expansive soil which collected from the middle Nile Delta, Egypt. To fulfil this objective, a number of laboratory tests were carried on the clay loam soil samples collected from the depth of 0-30 cm. Clay loam soils were treated by sawdust at the rate of 0%, 1%, 2%, 5%, 10%, 15% and 20% on the dry weight basis. Various experimental methods were used to determine the variations in the falling-head permeability, the clay size fraction, the plasticity index, the linear shrinkage and the cracking width with different sawdust-amended soils. The results showed that the addition of sawdust decreases the clay size fraction, the plasticity index, the linear shrinkage and the cracking width, while it increases significantly the falling-head permeability, which is a sign improvement of soil hydro-physical properties. It can be concluded that sawdust had the potential to improve the hydro-physical properties of expansive soils, especially, when added into soil in between one to two percent on dry weight basis, above this percentage the improvement was much less significant and warranted by the clay content decrease.