March 4, 2009

New design model cuts construction costs

U.S. engineers have created a design model that allows the use of 30 percent less reinforcing steel in precast concrete beams without sacrificing safety.

North Carolina State University civil engineering Professor Sami Rizkalla says the new spandrel design simplifies construction for precast concrete producers, noting that in addition to using less steel, the new design cuts labor and manufacturing time in half -- significantly decreasing costs.

One of the researchers, doctoral student Greg Lucier, said the new design guidelines include a significant margin for safety. For example, Lucier said the spandrels could handle two to three times the maximum weight they would be expected to bear.

An overview of the entire project, including new testing data, will be presented during the March 15-19 convention of the American Concrete Institute in San Antonio.