Deck panels can be used for both new construction and rehabilitation projects. They have been used successfully on deck replacement projects and bridge widening projects. For bridge widening projects, the existing deck needs to be cut back in order to expose the existing deck reinforcing bars so that a simple closure pour can be made to connect the old deck with the new deck.

This depends on the details chosen. One common option is to use longitudinal post-tensioning to connect the panels and to provide net compression in the deck under all service load conditions (including negative moment regions of continuous spans). In this scenario, there are several distinct construction steps that need to be applied in sequence (see answer to sequence question under” Construction” below. Even with this sequence, it is possible to replace a single span deck in one weekend (including old deck removal). Note that this requires the use of high early strength materials for grouting and closure pours. For typical construction projects that are not under a critical time frame, it is safe to assume that even a multi-span bridge can be built in one to two weeks.

There are no national or FHWA standards for deck panels; however there are many states using them. States tend to use proven details from other states; therefore some level of standardization has emerged. Several organizations have developed state and regional standards. These are based on successful details that have been proven in the field. Research reports and the new PCI “State of the Art Report on Full-depth Precast Concrete Bridge Deck Panels” are also a good source of details.

This is a common question that has no easy answer. It depends on many factors including size of project, number of similar projects, details used and access at the site. We have seen some projects cost 50% higher than CIP (small projects with complex geometry), but others be less than CIP (large project with significant repetition). Another factor is the number of projects that are built in a region. As contractors and fabricators become familiar with the process, the level of risk decreases which normally coincides with a decrease in cost.

Many agencies specify overlays for deck panel projects. The overlays serve two purposes. First, they provide a final tolerance adjustment to the top surface of the panels. Even with the best fabrication and construction practices, the final riding surface can be rough. The installation of an overlay will provide a smooth riding surface. Overlays can also be used to provide an additional layer of protection for the deck. Two systems are in use in the US; bituminous concrete pavement with a high quality membrane waterproofing system and thin concrete overlays. Both systems can provide a significant measure of deck protection.

Another option is to use a thin overlay system. This is normally used in conjunction with profile grinding of the deck in order to get a smooth riding surface. Tighter fabrication tolerances are also recommended for this option since grinding is normally limited to approximately ¼”. Match casting or line casting of the panels is recommended to achieve this level of quality.