Mixing native soil with empty oil palm ash bunches and cement is an attempt to increase the clay soil bearing capacity. The purpose of this study was to determine the effect of adding 5% of oil palm ash and cement bunches of 0%, 5%, 7.5%, and 10%, respectively, to the value of free compressive strength. The contribution of this research can later become recommendations for handling soil improvement. The method used is the testing of the compressive strength-free soil stabilization in a laboratory that refers to SNI 3638: 2012. The results showed that the clay studied was high clay plasticity with a liquid limit value of 55.3%. The addition of empty oil palm bunches ash and cement tends to reduce the value of the soil liquid limit to 41.77% at a percentage of 5% empty oil palm bunches ash and 10% cement. The strength value of soil bearing capacity increased to 4.90 kg/cm² on 5% ash of empty oil palm bunches and 10% of cement at 0 days ripening. The carrying value of native soil is 1.96 kg/cm². The conclusion is that the addition of oil palm and cement bunches ash tends to reduce the value of soil consistency and increase the value of the compressive strength of the soil. Addition of Empty oil palm bunches ash and cement can be an alternative to stabilizing clay soils.

In this study, additive of waste cooking oil waste in the Asphalt Concrete-Wearing Course (AC-WC) mixture emphasizes the pore content of the asphalt mixture. In this study the application of waste cooking oil waste by 1%, 2%, 3%, 4%, and 5% of the optimum asphalt content. Judging from the mixed pore content in this study, it was found that by adding 1% the pore value was 4.61%; an additional 2% obtained a pore digit value of 4.64%; an additional 3% obtained a pore number value of 5.22%; at the addition of 4%, the pore value is 11.10%; and the addition of 5% obtained a pore number value of 11.47%. This indicates that the greater the level of addition of waste cooking oil waste, the higher the pore value obtained so that the mixture is less impervious to water and air so that the mixture will be more easily absorbed by water and oxidized. Thus resulting in accelerating the aging of the asphalt.