Less steel for concrete

Researchers from North Carolina State University have discovered how to use 30 per cent less reinforcing steel in the manufacture of the concrete beams.


Researchers from North Carolina State University have discovered how to use 30 per cent less reinforcing steel in the manufacture of the concrete beams, or spandrels, used in the construction of parking garages without sacrificing safety.


Dr Sami Rizkalla, one of the leaders of the research team, said that the new spandrel design simplifies construction for precast concrete producers. In addition to using less steel, the new design cuts labour and manufacturing time in half – significantly decreasing costs.


Greg Lucier, a doctoral student at NC State who was also crucial to the research effort, said the new spandrels could handle two to three times the maximum weight they would be expected to bear.


Lucier is also the lab manager of the Constructed Facilities Laboratory at NC State, which oversaw the testing of the new spandrel design.


The new design guidelines stem from a two-year project that was launched in January 2007, with support from the Precast/Prestressed Concrete Institute (PCI). PCI provided NC State with more than $400,000 (£288,000) in funding, materials and technical support over the life of the project.


The success of the project is already drawing interest from the concrete industry, with individual companies coming to NC State to get input on how to improve their products and manufacturing processes.


While the researchers have published some elements of the research project, they will present an overview of the entire project – including new testing data – for the first time at the spring convention of the American Concrete Institute in San Antonio this month.