The Effect of Adding Bamboo Leaf Ash and Cement on the Stability of Clay Soil

Subgrade soil or clay subgrade is a type of soil with very high pore water characteristics, causing problems for civil structures, both buildings and road pavements. Bamboo leaf ash contains several compounds such as silica (SiO₂) at 77.24%, while cement contains several calcium oxide (CaO) compounds at 60%. Bamboo leaf ash has a high silica content which functions as a support for pozzolanic reactions with clay soil. The variations in the mixture of bamboo leaf ash and cement used are 2%, 3%, 4%, 5% and 6% for bamboo leaf ash and 20% for cement by weight of soil, with a curing time of 4 days. From the two tests that have been carried out, namely soil compaction (Standard Proctor) and Unsoaked CBR (California Bearing Ratio), the optimum values ​​obtained for soil compaction (Standard Proctor) and CBR (California Bearing Ratio) Unsoaked are in the variation of soil + cement addition of 20% + Bamboo Leaf Ash 3%. In the soil compaction test (Standard Proctor), the dry volume weight value was 1,728 gr/cm3 and the optimum water content value was 16.02%, while in the Unsoaked CBR (California Bearing Ratio) the optimum CBR percentage value was 10.25%.