Slipform PaverOne of Iowa's most significant contributions to the construction of the Interstate Highway System was the invention of the slipform paver, which is also celebrating its 50th anniversary. The slipform paver was invented by materials engineers with the Iowa Highway Commission, now the Iowa Department of Transportation. The first commercial slipform paving machine was manufacturing by an Iowa company.
This invention revolutionized concrete paving in Iowa and the nation, improving the quality and performance of the portland cement pavement roadway, and greatly accelerating the rate in which concrete roadways could be constructed. Prior to this invention, wooden forms and steel or wooden stakes had to be manually installed as supports for the concrete prior to it being laid, much in the same manner that sidewalks are constructed today. This conventional forms method of paving roads was labor and time intensive and would have added years to construction of the interstate had been necessary to use it throughout the building of the system.
For more about the slipform paver, including photos of the original prototypes, explore the following featured article.