Comparative Assessment of Using Glass Powder and Aluminum Waste to Improve Unconfined Strength of Clay Soil

The soil strength is one of the essential mechanical soil properties that should be studied before constructing any project. This paper compares two clay soil samples, where one was improved by adding glass powder and another by aluminum waste. Each waste material was mixed with soil in varying percentages of 0%, 5%, 10%, and 15%, by the soil's weight, which was added as medium sand aggregate. Therefore, physical and mechanical tests are carried out on the samples. The physical tests showed that the soil classification changes from height plasticity CH to low plasticity CL for both materials at some percentage. The results of compaction tests showed that the addition of glass powder increases the dry densities (?d) of the samples, but the increasing rate of added aluminum waste decreases it. The higher amount of dry densities was at the 15% of additive of both materials. Adding glass powder increases the density of standard soil by 8.51%, while aluminum waste decreases it by 0.7%. However, the improvement in the value of the optimal water content (O.M.C) stopped at 10% and 15% of additive materials, respectively. The unconfined compression test showed that the values of unconfined strength U.C. decreased in the case of glass powder additive and increased when aluminum waste additive.