Stabilizing Clay Soil With Cement Reviewed From The Value Of CBR In The Plandaan District, Jombang Regency

Basically, clay soil has high plasticity, relatively high swelling and shrinkage capacity, and low bearing capacity or soil strength. If a civil engineering structure is built on clay soil, problems will arise with the soil itself, namely settlement and sliding. To overcome this bad clay soil, it is necessary to improve the soil. Stabilization can use two methods, namely: mechanical methods and chemical methods. The chemical stabilization method for clay soil is using cement. Cement is a good stabilizing agent, because its ability to harden and bind aggregate grains is very good in an effort to obtain a soil mass that is sturdy and resistant to deformation. The test for the soil strength value in this case is CBR. This is done by mixing clay and cement materials with variations (7%, 12%, 17% and 22%) and curing for: 7, 14 and 21 days. From the research results, the original CBR value was 2.5% after stabilization with cement material, the CBR value increased with the most optimum CBR value of 18.04% with the addition of 7% cement material with a curing period of 7 days, with a curing period of 14 days the most optimum value amounted to 36.7% at a cement content of 17% and the most optimum CBR value was 41.37% with the addition of 17% cement material with a curing period of 21 days. The effect of adding cement to the soil on the curing CBR test increases based on the increasing age of curing in the soil because the added cement provides an increase in the carrying capacity of both the portion of the mixture and the duration of curing.The maximum CBR in 5% cement is 22.78%, the CBR value of the undisturbed soil is
4.88%.