Relation between Swelling Potential and Swelling Pressure for different Types of Expansive Clay of New Cairo

The purpose of this paper is to present correlations that may help in predicting swelling pressure (PS) and swelling potential (SP) for expansive clay, which can contribute to solving engineering problems such as cracking, shifting or other structural damage, that may occur, if the behavior of this type of soil is not taken into consideration. Therefore, in this research, five different samples of expansive clay soils were collected from different site locations in New Cairo, Egypt. Then, these samples were dried, pulverized and passed through sieve No. 40 (0.425 mm). The samples were prepared initially at maximum dry density (MDD) and optimum moisture content (OMC) by carrying out the standard proctor compaction test. After that, the values of swelling pressure (PS) and swelling potential (SP) were measured by using the oedometer apparatus. Also, the percentage of clay in each sample was determined by the use of hydrometer analysis, and plasticity index (PI) by applying Atterberg limits. In addition, the clay activity (A) values were calculated. Consequently, equations were deduced to estimate swelling pressure and swelling potential using the activity (A). Furthermore, another equation was deduced to calculate swelling pressure by using both the activity and swelling potential.