摘要：Moch. Sholeh1 & Dandung Novianto2 1 & 2Fakultas Teknik Jurusan Teknik Sipil Politeknik Negeri Malang ABSTRACT Clay consists of grains - grains are very small (<0002 mm) and shows the nature - the nature of plasticity and cohesion. Cohesion indicates the fact that part - the part that is attached to each other, while the plasticity is a trait that allows the form of the material was changed - edit without changing the content or without returning to its original form, and without any cracks or brokens. And clay with high plasticity index has strong support low when used as a basic foundation of the highway, so the need for soil improvement. From the above problems then this study aims to engineer clay with red brick powder in four comparisons. The first native land. Both the original soil mixed with red brick powder 5%. The third native soil mixed with red brick powder 7.5%. The four original soil mixed with red brick powder 10%. Each of these sought specific gravity, liquid limit, plastic limit and plasticity index on the original soil, mixing 5%, 7.5% and 10%. From the analysis of data obtained the following conclusion: the original soil, the value amounting to 60.9 Liquid limit, plastic limit values of 42.8 and plasticity index value of 18.1. The most optimal additional percentage is 7.5%. And Plasticity Index value at 7.5% is 20,31. Key words : Red brick powder, Soil Stability, Subgrade and the Road
