About the research
Horizontal curves make up a small percentage of total road miles, yet account for one-quarter of all highway fatalities. The majority of crashes on curves involve lane departures. The Sequential Dynamic Curve Warning System consists of a series of solar-powered, LED-enhanced BlinkerSigns (a Curve Warning BlinkerSign and an array of Chevron BlinkerSigns) that are installed throughout a curve. Approaching vehicles, sensed by radar or other ITS device, trigger the controller that wirelessly activates the LED signs to flash sequentially through the curve to warn speeding drivers to slow down. The field study will evaluate the effectiveness of the technology in reducing vehicle speeds and in reducing the frequency and/or the severity of curve-related crashes. Participating State DOTs include Iowa, Missouri, Texas, Washington, and Wisconsin.
About the research
As a part of an innovation project funded by the Federal Highway Administration (FHWA) Highways for LIFE program, a full-depth precast, ultra-high-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementation of waffle decks were developed.
Following a successful full-scale validation test on a unit consisting of two panels and there different types of connections under laboratory conditions, the waffle deck was successfully installed on a replacement bridge in Wapello County, Iowa. The subsequent load testing confirmed the desirable performance of the UHPC waffle deck bridge.
Using the lessons from the completed project and outcomes from a series of simple and detailed finite element analyses of waffle decks, this report was developed to serve as a guide for broadening the design and installation of the UHPC waffle deck panel in new and existing bridges.
Following an introduction to UHPC and waffle deck panels and a summary of completed work, the report presents information on: design of waffle deck, design of connections, redecking using waffle deck panels, and guidance on precast fabrication, construction, and installation of UHPC waffle deck panels.