Concrete, Inc. in Grand Forks, N.D., is a company that produces and erects prestressed/precast concrete building components. The prestress sector was founded in 1968. In the 1970s Concrete, Inc. entered the market by producing and selling double tees for wall panels and roof members to general contractors. Concrete, Inc. is one of the more than 200 certified plants in the United States and offers a wide array of concrete building components, such as structural concrete columns, beams, double tees and flat slab panels to intricate architectural work. The company s sales and marketing staff covers the tri-state region of North Dakota, Minnesota and South Dakota.