An Experimental Study for Identification and Comparison of Plastic Index and Shrinkage Properties of Clay Soils with the Addition of Cement

چکیده مقاله

There has been an increasing application of various clay minerals with high plasticity in environmental and
geotechnical projects. One of the weaknesses of clay minerals is their shrinkage potential while desiccating. It is imperative to modify the properties of these minerals by combining them with other materials. The present article tries to examine the effect of adding cement to clay on its shrinkage properties and to compare it with normal clay.
A considerable number of expansion experiments were carried out on mixed samples with different weight
percentages. The results suggested the significant effect of modification of clay soils in Golestan Province by adding cement on their shrinkage properties, such that increased percentage of additives increases the shrinkage limit of clay-additive mixture and the cracks caused by shrinkage decrease in terms of length and width. Finally, the clayadditive mixture pattern can be obtained that provides the basic, necessary properties which correspond to the aims of the project. In the present article, cement is used as a chemical for improving the shrinkage properties of expansive and problematic soils in Golestan Province. During the course of experiments, four samples of different soils are used with plasticity indices of 20, 30, 35, and 40. Here, the plasticity properties (including liquid limit,
plastic limit, shrinkage limit, and plastic index) of clay soils in the region will be examined and compared before and after adding different percentages of cement.