High-Early Strength Concrete for Rapid Bridge Deck Repair and Rehabilitation
Bridge deck cracking is a prevalent problem in the United States. While early-age cracking will not cause failure of the bridge deck system independently, the penetration of deleterious substances (e.g., deicing chemicals) through the cracks leads to costly serviceability issues. If left unchecked these issues could lead to severe distress and the loss of structural integrity of the deck and superstructure. Bridge deck deterioration, therefore, must be managed through preservation efforts that range in scope from patch repairs to full deck replacement, with bridge deck concrete overlays and overlay replacement falling somewhere in between. There is also a need to strengthen some bridges due to higher demands, including increasing deck thickness through a structural overlay. Regardless of the scope of the rehabilitation project, one of the continuing challenges in these efforts is selecting a suitable repair material that can achieve specified engineering and durability properties quickly while also being long-lasting. As traffic volumes continue to increase, long-term closures or lane restrictions are nearly impossible, and many of these preservation projects must be completed during overnight closure windows, often in congested and heavily trafficked urban transportation corridors. Currently, there are a number of repair and overlay materials available for protecting bridge decks from additional deterioration and extending their service life (e.g., ultra high-performance concrete, latex modified concrete, low slump concrete, etc.) [1-5]. Many of these overlay systems have shown varying degrees of success but mobility and safety issues have caused state DOTs to truncate construction times as much as possible, leaving less time for these conventional strength-gaining materials to be used. This has led to instances of using expensive polymer-based concretes (e.g., polyester polymer concrete or PPC) instead of preferred or higher-performing cementitious materials due to rapid traffic turnaround; PPC overlays set up very fast, but they do not address decks in poor condition and are expensive. Consequently, there is an urgent need in identifying, characterizing, and implementing sustainable and advanced high-early strength concrete (HESC) overlays to support rapid concrete bridge deck rehabilitation. The proposed research project explores the use of a calcium sulfoaluminate (CSA) cement-based overlay as alternative option. CSA is a preferred option for HESC because of its ability to set within a short time window (roughly 15 min) and easily surpass a compressive strength of 2,500 psi in under 3 hours. A primary reason for the rapid strength development in CSA is due to its finer particle size, when compared with ordinary Portland cement (OPC), and a chemistry that promotes rapid and significant ettringite formation in the first few hours [6]. This rapid ettringite formation often leads to an early-age expansion characteristics resulting in a lower or neutral long-term shrinkage stress development and thus, reducing cracking potential. While the main incentive for using CSA is the rapid strength gain, it is worth noting that its lower calcium composition leads to a 30-50% reduction in CO2 emission from calcination compared to OPC [7]. Furthermore, the lower temperature needed in the kiln to produce the CSA compounds can reduce the energy of manufacturing by up to 60% [8]. A survey done in 2017 reported that California is the only state DOT recommending the use of CSA for high early strength concrete [9]. However, another survey found that 9 other states, including Washington, have had success using CSA for repair applications [10]. While CSAs have the potential to be successfully used in producing HESC overlays, significantly more data is needed in order to develop appropriate guidance and specification documents for their use. The construction of concrete overlays presents a unique problem, where sufficient bonding and compatibility between the overlay material and the substrate is essential for a long-lasting rehabilitation. The use of HESC in this application presents several additional challenges, where conventional bridge overlay construction practice may not work for these materials. The ideal material should possess high early-age strength, good adhesion to existing concrete substrates, and superior short- and long-term durability. These properties will be evaluated in the proposed testing program to develop a suitable CSA based HESC overlay material specification for accelerated bridge construction and rehabilitation applications
Language
- English
Project
- Status: Active
- Funding: $70000
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Contract Numbers:
69A3551747121
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Sponsor Organizations:
Accelerated Bridge Construction University Transportation Center (ABC-UTC)
Florida International University
10555 W. Flagler Street
Miami, FL United States 33174Office of the Assistant Secretary for Research and Technology
University Transportation Centers Program
Department of Transportation
Washington, DC United States 20590 -
Performing Organizations:
University of Washington, Seattle
Civil and Environmental Engineering Department
201 More Hall, Box 352700
Seattle, WA United States 98195-2700 -
Principal Investigators:
Thonstad, Travis
- Start Date: 20230515
- Expected Completion Date: 0
- Actual Completion Date: 0
- USDOT Program: University Transportation Centers
Subject/Index Terms
- TRT Terms: Bridge decks; Calcium sulfates; High early strength cement; Mix design; Overlays (Pavements); Repairing
- Subject Areas: Bridges and other structures; Construction; Highways; Maintenance and Preservation; Materials;
Filing Info
- Accession Number: 01889316
- Record Type: Research project
- Source Agency: Accelerated Bridge Construction University Transportation Center (ABC-UTC)
- Contract Numbers: 69A3551747121
- Files: UTC, RIP
- Created Date: Jul 31 2023 12:24AM