This course is designed to fulfill continuing education requirements for civil engineers. It delineates criteria for improving the engineering properties of soils used for pavement base courses, sub-base courses, and sub-grades by the use of additives which are mixed into the soil to effect the desired improvement. These criteria are also applicable to roads and airfields having a stabilized surface layer. Unless otherwise noted, all information in this course was obtained from the U.S. Army Corp of Engineers Website.