Validation of Rehab Strategies of Extend the Service Life of Concrete Bridge Decks
Started: July, 2008 Ended: June, 2013 Project ID #4W2179 Status: Completed
The objective of this research is to investigate the long-term effectiveness of Caltrans’ preservation and rehabilitation strategies for concrete bridge decks. Caltrans currently employs high molecular weight methacrylate (HMWM)-based crack sealing and polyester overlay. This research will also explore the value of Portland cement concrete (PCC) and asphalt concrete (AC) overlays on bridge decks, and identify the appropriate treatment time and frequency for these strategies.
Concrete box girder bridges with integral decks are the predominant bridge type in California. Instead of unreliable and expensive deck replacement, Caltrans currently employs preservation and rehabilitation strategies, mainly using HMWM-based crack sealing and polyester overlay. The current state-of-the-practice relative to rehabilitating bridge decks using these methods, as well as PCC and AC overlay, will be assessed by reviewing existing literature. Critical factors and variables that influence the effectiveness and durability of these practices in California will be identified. As critical parameters are identified, a series of laboratory experiments will be conducted to obtain load cycle vs. deterioration relationships for deck slabs under various conditions before and after protective treatment. A laboratory-based accelerated tester will be fabricated to test deck slabs under rolling loads and well-controlled environmental conditions. The load cycle vs. deterioration relationships will address strength loss and reinforcement corrosion of the deteriorated concrete, which are two of Caltrans’ primary concerns for its bridge decks. A two-dimensional (2D) finite element method (FEM) model will be developed to simulate the ingress of chloride and moisture into deck slabs. The load cycle vs. wheel-path stiffness, chloride permeability and moisture permeability curves obtained from the laboratory test will then be combined with the 2D FEM model to predict the service life of each rehabilitation strategy. A life-cycle cost analysis will be performed to determine the most cost-effective rehabilitation strategies for Caltrans bridge decks.
Eli Cuelho - PI
Steve Sahs - Main External Contact
Sponsors & Partners
- California Department of Transportation (CALTRANS) Sponsor