Improving Concrete Overlay Construction

Several road construction projects involving concrete overlays at the state and county levels in Iowa in 2009 were studied for construction techniques and methods. The projects that were evaluated consisted of sites in four Iowa counties: Osceola, Worth, Poweshiek, and Johnson counties. The construction techniques and methods that were studied included concrete overlays and material usage. By evaluating these methods, highway agencies can explore different ways of making road construction less costly and can minimize the amount of time that the traveling public is exposed to road construction. Research conclusions are offered in the following areas: Longitudinal joint formation; Global Positioning System mapping of pavement surfaces for concrete surface profile and quantity calculations; Milling; Slipform paver machine control; Stringless paving; Geotextile bond breakers; Concrete opening strength requirement for local traffic use; Traffic control for one- and two-lane overlay construction; Overlay construction operation timing; and Falling weight deflectometer testing.