Concrete is a mixture of cement, water, sand, gravel, crushed rock, or other aggregates. Sometimes, one or more admixtures are added to change certain characteristics of the concrete, such as workability, durability, and time of hardening.
Top 100 Colleges by Highest Tuition. Here are the top 100 most expensive colleges by tuition for the 2008-2009 school year. The latest numbers can be found in our most expensive colleges ranking. Notes: Some colleges like Bates College, Colby College, Middlebury College, and Union College have a comprehensive fee (tuition + room/board).
Scott Ralls, Ph.D. President, Northern Virginia Community College. Scott Ralls is the fifth president of Northern Virginia Community College (NOVA). With approximately 75,000 degree students, NOVA is the 11th largest college in the United States and annually awards more associate degrees than any other individual post-secondary institution.