Abstract
The presence of gypsum in soil as bond agent alters its behavior, in other words, there is a large influence of gypsum on the physical and mechanical properties of soil. This influence depends mainly on the amount and type of gypsum presented in the soil.
The soils used in this study were brought from one locations at Al-Tar region west of Al-Najaf city. These soils had gypsum content of 35%. The classification tests indicate that the soil is poorly graded. In this paper an experimental study is carried out on the effect of three different additives to the gypseous soil in order to improve the compaction properties of the gypsum soil. The additives used in this study were cement, ceramic and mix of cement and ceramic. The percentages of ceramic was varied between 4-12% in the first series whereas percentage of cement was between 4-8% by weight in the second series. In the third series the percentage of cement was kept constant 4% by weight while the percentage of ceramic varied from 4 to 12% by weight. Control groub without any additive was also tested to determine the effect of additives. The results show that the best improvement in compaction characteristics test is achieved when the sample is treated with adding mix of cement and ceramic, the maximum dry density only increase with the increases in mixing content, while the opposite is true for the optimum water content. The results also show that the maximum dry density of treated gypsum soil with ceramic material increases with the increase in ceramic content up to 8% after which the density decreases.
