ABSTRACT
Lidah Formation that contains of blue gray mudstone with some lenses of carbonates sandstone and limestone are wide spread in the north part of East Java, Indonesia. The weathering process of this geologic formation produces expansive clayey soil. The engineering properties of this soil are low California Bearing Ratio (CBR) and high swelling index. The aim of this research is to improve engineering properties by using the industrial solid waste (fly ash of coal burning, air cooled blast furnaces slag, and mixing of these). The laboratory experiment carried out after ASTM. The CBR (California Bearing Ratio) tests were executed in un-soaked and soaked condition. The swelling index tests were carried out to explore the changing of expansivity properties of clayey soil until the maximum value is reached. The experiment’s results showed that the addition of industrial solid waste less than 10% of dry weight can increase the CBR value and decrease of swelling index.
