Modifying the Behavior of Expansive Soils with Hydrophobic Wax Additives

The main purpose of this research is to look at how paraffin wax (PW) can be used to treat the top level of expansive soil by lowering the amount of water that reaches it which in turn lowers the soil's swelling potential. Covering the natural expansive soil with wax helps keep its natural properties and its moisture content. In this study the soil will be treated with PW at levels of 0%, 5%, 10%, 15% and 20% by the weight of the dry soil. The geotechnical engineering features of both the untreated soil and the soil mixed with PW were tested. Results show that adding 20% PW particles, decreases the free swelling by 64%, swelling pressure by 57%, and swelling potential by 61%. Also lowers the soil’s highest dry density by 16.7% and reduces the optimum moisture content (OMC) by 53%. There is also an Additionally, adding PW also reduces the unconfined compressive strength by up to 24.69%. Even though there is a reduction, it doesn't matter much for lightweight buildings, which are the main structures that need to be protected from swelling soils. Thus, using PW can be a good alternative to deal with expansive soil problems in some situations. This method is also cost-effective because it lowers the expensive costs of soil replacement and creates new uses for paraffin wax, which is a byproduct of petroleum.