Final Scope 

A complementary bridge deck protection system is comprised of deck treatments (AASHTO Element 510 Wearing Surface and Element 521 Concrete Protective Coating) constructed together as a system to extend the service life of a deck beyond what either treatment would achieve if used separately.

Once a bridge is constructed and put into service, it begins to deteriorate. One of the most vulnerable bridge components to deterioration is the bridge deck.  Decks are often exposed to contaminants and adverse weather conditions (deicing chemicals, road salts, etc.), water, freeze thaw conditions, and saltwater environments.  Water and contaminants can penetrate concrete and cause accelerated deterioration. 

State departments of transportation (DOTs) undertake a variety of strategies in design, construction, and maintenance to minimize, reduce, and slow down the deterioration of their bridges. Many bridge decks have overlays, such as: asphalt only, asphalt with a liquid applied waterproof membrane, asphalt with a sheet applied waterproof membrane, rigid cementitious concrete, latex modified concrete, premixed polymer concrete with primer, multi-layer polymer concrete with primer, etc.  These overlays function as protective wearing surfaces that reduce the amount of water and contaminants permeating the underlying deck concrete, thereby increasing the service life of the deck.  However, they may obscure the condition and hide the deterioration of the underlying deck.

Some state DOTs use overlays in conjunction with deck treatments, such as: concrete penetrating sealers, crack sealers or healer sealers, or a combination of sealer types.  These complementary bridge deck protection systems further extend the service life of decks because the top layer of protection (the overlay) has to fail before the second layer of protection (the sealer) begins to work.  Using a complementary bridge deck protection system may give state DOT bridge owners latitude of when to replace the overlay without experiencing significant deck deterioration.   The cost of applying a concrete penetrating sealer, crack sealer, or healer sealer is estimated to be 2% the cost of replacing a deck, 4% the cost of a partial depth deck replacement, and 1% the cost of new bridge construction. However, even at this relatively low cost, it is unknown how extensively complementary bridge deck protection measures are used.

The objective of this synthesis is to document state DOT practices for the selection and use of complementary bridge deck protection systems (single or combined).  The synthesis encompasses current practices for designing (selecting a deck treatment combination), installing, maintaining, replacing, and successively using complementary bridge deck protection systems to extend the service life of bridge decks.

Information to be gathered includes (but is not limited to):

• Deck protection or preventative treatments (include but limit to overlay or sealer) used as a single (standalone) deck protection strategy;
• Complementary bridge deck protection systems bridge used, including the combination of treatments that comprise the systems and duration of use;
• Factors and constraints considered when selecting and designing appropriate deck protection systems;
• Written policies, guidelines, specifications, testing data for decision-making on individual or complementary deck protection systems;
• Strategies and practices for installing, maintaining, and replacing complementary deck protection systems or individual treatments within the system;
• Criteria and testing (e.g., NDE testing) used to evaluate performance, and
• Performance of complementary bridge deck protection systems. 

Information will be gathered through a literature review, a survey of bridge owners, and follow-up interviews with selected bridge owners for the development of case studies. Knowledge gaps and suggestions for future research to address those gaps will be identified.

TRB Staff
Zhiye Li 
Email: zli@nas.edu

Meeting Dates
First Panel Meeting: 02/06/2025 (Virtual via Zoom)
Teleconference with Consultant: 03/14/25 (Virtual, via Zoom) 
Second Panel Meeting: 11/06/25 (In-person, in Washington, DC)

Panel Members
Ryan Bowers, Wisconsin Department of Transportation
Haylye Brown, Louisiana Department of Transportation and Development
Hung-Wen (Oliver) Chung, Florida Department of Transportation
Leslie Daugherty, Alaska Department of Transportation and Public Facilities
Samer Rabie, New Jersey Department of Transportation
Chengcheng Tao, Purdue University
Ping Lu, Federal Highway Administration (FHWA)